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Introduction to Paleoanthropology/Hominids MiddlePaleolithic

The second phase of human migration
The time period between 250,000 and 50,000 years ago is commonly called the Middle Paleolithic.

At the same time that Neanderthals occupied Europe and Western Asia, other kinds of people lived in the Far East and Africa, and those in Africa were significantly more modern than the Neanderthals.

These Africans are thus more plausible ancestors for living humans, and it appears increasingly likely that Neanderthals were an evolutionary dead end, contributing few if any genes to historic populations.

Topics to be covered in this chapter:
 * Summary of the fossil evidence for both the Neanderthals and some of their contemporaries;
 * Second phase of human migration ("Out-of-Africa 2" Debate)

History of Research
In 1856, a strange skeleton was discovered in Feldhofer Cave in the Neander Valley (in German "Neandertal" but previously it was called "Neanderthal", "thal" = valley) near Dusseldorf, Germany. The skull cap was as large as that of a present-day human but very different in shape. Initially this skeleton was interpreted as that of a congenital idiot.

The Forbes Quarry (Gibraltar) female cranium (now also considered as Neanderthal) was discovered in 1848, eight years before the Feldhofer find, but its distinctive features were not recognized at that time.

Subsequently, numerous Neanderthal remains were found in Belgium, Croatia, France, Spain, Italy, Israel and Central Asia.

Anthropologists have been debating for 150 years whether Neanderthals were a distinct species or an ancestor of Homo sapiens sapiens. In 1997, DNA analysis from the Feldhofer Cave specimen showed decisively that Neanderthals were a distinct lineage.

These data imply that Neanderthals and Homo sapiens sapiens were separate lineages with a common ancestor, Homo heidelbergensis, about 600,000 years ago.

Anatomy
Unlike earlier hominids (with some rare exceptions), Neanderthals are represented by many complete or nearly complete skeletons. Neanderthals provide the best hominid fossil record of the Plio-Pleistocene, with about 500 individuals. About half the skeletons were children. Typical cranial and dental features are present in the young individuals, indicating Neanderthal features were inherited, not acquired.

Morphologically the Neanderthals are a remarkably coherent group. Therefore they are easier to characterize than most earlier human types.

Neanderthal skull has a low forehead, prominent brow ridges and occipital bones. It is long and low, but relatively thin walled. The back of the skull has a characteristic rounded bulge, and does not come to a point at the back.

Cranial capacity is relatively large, ranging from 1,245 to 1,740 cc and averaging about 1,520 cc. It overlaps or even exceeds average for Homo sapiens sapiens. The robust face with a broad nasal region projects out from the braincase. By contrast, the face of modern Homo sapiens sapiens is tucked under the brain box, the forehead is high, the occipital region rounded, and the chin prominent.

Neanderthals have small back teeth (molars), but incisors are relatively large and show very heavy wear.

Neanderthal short legs and arms are characteristic of a body type that conserves heat. They were strong, rugged and built for cold weather. Large elbow, hip, knee joints, and robust bones suggest great muscularity. Pelvis had longer and thinner pubic bone than modern humans.

All adult skeletons exhibit some kind of disease or injury. Healed fractures and severe arthritis show that they had a hard life, and individuals rarely lived past 40 years old.

Chronology
Neanderthals lived from about 250,000 to 30,000 years ago in Eurasia.

The earlier ones, like at Atapuerca (Sima de Los Huesos), were more generalized. The later ones are the more specialized, "classic" Neanderthals.

The last Neanderthals lived in Southwest France, Portugal, Spain, Croatia, and the Caucasus as recently as 27,000 years ago.

Geography
The distribution of Neanderthals extended from Uzbekistan in the east to the Iberian peninsula in the west, from the margins of the Ice Age glaciers in the north to the shores of the Mediterranean sea in the south.

South-West France (Dordogne region) is among the richest in Neanderthal cave shelters:
 * La Chapelle-aux-Saints;
 * La Ferrassie;
 * Saint-Césaire (which is one of the younger sites at 36,000).

Other sites include:
 * Krapina in Croatia;
 * Saccopastore in Italy;
 * Shanidar in Iraq;
 * Teshik-Tash (Uzbekistan). The 9-year-old hominid from this site lies at the most easterly known part of their range.

No Neanderthal remains have been discovered in Africa or East Asia.

Chronology and Geography
The time and place of Homo sapiens origin has preoccupied anthropologists for more than a century. For the longest time, many assumed their origin was in South-West Asia. But in 1987, anthropologist Rebecca Cann and colleagues compared DNA of Africans, Asians, Caucasians, Australians, and New Guineans. Their findings were striking in two respects:
 * the variability observed within each population was greatest by far in Africans, which implied the African population was oldest and thus ancestral to the Asians and Caucasians;
 * there was very little variability between populations which indicated that our species originated quite recently.

The human within-species variability was only 1/25th as much as the average difference between human and chimpanzee DNA. The human and chimpanzee lineages diverged about 5 million years ago. 1/25th of 5 million is 200,000. Cann therefore concluded that Homo sapiens originated in Africa about 200,000 years ago. Much additional molecular data and hominid remains further support a recent African origin of Homo sapiens, now estimated to be around 160,000-150,000 years ago.

Earliest Evidence
The Dmanisi evidence suggests early Europeans developed in Asia and migrated to Europe creating modern Europeans with minor interaction with African Homo types. July 5 2002 issue of the journal Science and is the subject of the cover story of the August issue of National Geographic magazine. New Asian finds are significant, they say, especially the 1.75 million-year-old small-brained early-human fossils found in Dmanisi, Georgia, and the 18,000-year-old "hobbit" fossils (Homo floresiensis) discovered on the island of Flores in Indonesia.

Such finds suggest that Asia's earliest human ancestors may be older by hundreds of thousands of years than previously believed, the scientists say. Robin Dennell, of the University of Sheffield in England, and Wil Roebroeks, of Leiden University in the Netherlands, describe their ideas in the December 22, 2005 issue of Nature. The fossil and archaeological finds characteristic of early modern humans are represented at various sites in East and South Africa, which date between 160,000 and 77,000 years ago.

Herto (Middle Awash, Ethiopia)
In June 2003, publication of hominid remains of a new subspecies: Homo sapiens idaltu. Three skulls (two adults, one juvenile) are interpreted as the earliest near-modern humans: 160,000-154,000 BP. They exhibit some modern traits (very large cranium; high, round skull; flat face without browridge), but also retain archaic features (heavy browridge; widely spaced eyes). Their anatomy and antiquity link earlier archaic African forms to later fully modern ones, providing strong evidence that East Africa was the birthplace of Homo sapiens.

Omo-Kibish (Ethiopia)
In 1967, Richard Leakey and his team uncovered a partial hominid skeleton (Omo I), which had the features of Homo sapiens. Another partial fragment of a skull (Omo II) revealed a cranial capacity over 1,400 cc. Dating of shells from the same level gave a date of 130,000 years.

Ngaloba, Laetoli area (Tanzania)
A nearly complete skull (LH 18) was found in Upper Ngaloba Beds. Its morphology is largely modern, yet it retains some archaic features such as prominent brow ridges and a receding forehead. Dated at about 120,000 years ago.

Border Cave (South Africa)
Remains of four individuals (a partial cranium, 2 lower jaws, and a tiny buried infant) were found in a layer dated to at least 90,000 years ago. Although fragmentary, these fossils appeared modern.

Klasies River (South Africa)
Site occupied from 120,000 to 60,000 years ago. Most human fossils come from a layer dated to around 90,000 years ago. They are fragmentary: cranial, mandibular, and postcranial pieces. They appear modern, especially a fragmentary frontal bone that lacks a brow ridge. Chin and tooth size also have a modern aspect.

Blombos Cave (South Africa)
A layer dated to 77,000 BCE yielded 9 human teeth or dental fragments, representing five to seven individuals, of modern appearance.

Anatomy
African skulls have reduced browridges and small faces. They tend to be higher, more rounded than classic Neanderthal skulls, and some approach or equal modern skulls in basic vault shape. Where cranial capacity can be estimated, the African skulls range between 1,370 and 1,510 cc, comfortably within the range of both the Neanderthals and anatomically modern people.

Mandibles tend to have significantly shorter and flatter faces than did the Neanderthals.

Postcranial parts indicate people who were robust, particularly in their legs, but who were fully modern in form.

Out-of-Africa 2: The debate
Most anthropologists agree that a dramatic shift in hominid morphology occurred during the last glacial epoch. About 150,000 years ago the world was inhabited by a morphologically heterogeneous collection of hominids: Neanderthals in Europe; less robust archaic Homo sapiens in East Asia; and somewhat more modern humans in East Africa (Ethiopia) and also SW Asia. By 30,000 years ago, much of this diversity had disappeared. Anatomically modern humans occupied all of the Old World.

In order to understand how this transition occurred, we need to answer two questions:
 * 1) Did the genes that give rise to modern human morphology arise in one region, or in many different parts of the globe?
 * 2) Did the genes spread from one part of the world to another by gene flow, or through the movement and replacement of one group of people by another?

Unfortunately, genes don't fossilize, and we cannot study the genetic composition of ancient hominid populations directly. However, there is a considerable amount of evidence that we can bring to bear on these questions through the anatomical study of the fossil record and the molecular biology of living populations. The shapes of teeth from a number of hominid species suggest that arrivals from Asia played a greater role in colonizing Europe than hominids direct from Africa, a new analysis of more than 5,000 ancient teeth suggests. (Proceedings of the National Academy of Sciences Aug 2007)

Two opposing hypotheses for the transition to modern humans have been promulgated over the last decades:
 * the "multi-regional model" sees the process as a localized speciation event;
 * the "out-of-Africa model" sees the process as the result of widespread phyletic transformation.

The "Multi-regional" model
This model proposes that ancestral Homo erectus populations throughout the world gradually and independently evolved first through archaic Homo sapiens, then to fully modern humans. In this case, the Neanderthals are seen as European versions of archaic sapiens.

Recent advocates of the model have emphasized the importance of gene flow among different geographic populations, making their move toward modernity not independent but tied together as a genetic network over large geographical regions and over long periods of time. Since these populations were separated by great distances and experienced different kinds of environmental conditions, there was considerable regional variation in morphology among them.

One consequence of this widespread phyletic transformation would be that modern geographic populations would have very deep genetic roots, having begun to separate from each other a very long time ago, perhaps as much as a million years.

This model essentially sees multiple origins of Homo sapiens, and no necessary migrations.

The "Out-of-Africa"/"Replacement" model
This second hypothesis considers a geographically discrete origin, followed by migration throughout the rest of the Old World. By contrast with the first hypothesis, here we have a single origin and extensive migration.

Modern geographic populations would have shallow genetic roots, having derived from a speciation event in relatively recent times. Hominid populations were genetically isolated from each other during the Middle Pleistocene. As a result, different populations of Homo erectus and archaic Homo sapiens evolved independently, perhaps forming several hominid species. Then, between 200,000 and 100,000 years ago, anatomically modern humans arose someplace in Africa and spread out, replacing other archaic sapiens including Neanderthals. The replacement model does not specify how anatomically modern humans usurped local populations. However, the model posits that there was little or no gene flow between hominid groups.

Hypothesis testing
If the "Multi-regional Model" were correct, then it should be possible to see in modern populations echoes of anatomical features that stretch way back into prehistory: this is known as regional continuity. In addition, the appearance in the fossil record of advanced humans might be expected to occur more or less simultaneously throughout the Old World. By contrast, the "Out-of-Africa Model" predicts little regional continuity and the appearance of modern humans in one locality before they spread into others.

Out-of-Africa 2: The evidence
Until relatively recently, there was a strong sentiment among anthropologists in favor of extensive regional continuity. In addition, Western Europe tended to dominate the discussions. Evidence has expanded considerably in recent years, and now includes molecular biology data as well as fossils. Now there is a distinct shift in favor of some version of the "Out-of-Africa Model".

Discussion based on detailed examination of fossil record and mitochondrial DNA needs to address criteria for identifying:
 * regional continuity;
 * earliest geographical evidence (center of origin);
 * chronology of appearance of modern humans.

Regional Continuity
The fossil evidence most immediately relevant to the origin of modern humans is to be found throughout Europe, Asia, Australasia, and Africa, and goes back in time as far as 300,000 years ago.

Most fossils are crania of varying degrees of incompleteness. They look like a mosaic of Homo erectus and Homo sapiens, and are generally termed archaic sapiens. It is among such fossils that signs of regional continuity are sought, being traced through to modern populations.

For example, some scholars (Alan Thorne) argue for such regional anatomical continuities among Australasian populations and among Chinese populations. In the same way, some others believe a good case can be made for regional continuity in Central Europe and perhaps North Africa.

Replacement
By contrast, proponents of a replacement model argue that, for most of the fossil record, the anatomical characters being cited as indicating regional continuity are primitive, and therefore cannot be used uniquely to link specific geographic populations through time.

The equatorial anatomy of the first modern humans in Europe presumably is a clue to their origin: Africa. There are sites from the north, east and south of the African continent with specimens of anatomical modernity. One of the most accepted is Klasies River in South Africa. The recent discovery of remains of H. sapiens idaltu at Herto (Ethiopia) confirms this evidence. Does this mean that modern Homo sapiens arose as a speciation event in Eastern Africa (Ethiopia), populations migrating north, eventually to enter Eurasia? This is a clear possibility.

The earlier appearance of anatomically modern humans in Africa than in Europe and in Asia too supports the "Out-of-Africa Model".

Molecular biology
Just as molecular evidence had played a major role in understanding the beginnings of the hominid family, so too could it be applied to the later history, in principle.

However, because that later history inevitably covers a shorter period of time - no more than the past 1 million years - conventional genetic data would be less useful than they had been for pinpointing the time of divergence between hominids and apes, at least 5 million years ago. Genes in cell nuclei accumulate mutations rather slowly. Therefore trying to infer the recent history of populations based on such mutations is difficult, because of the relative paucity of information. DNA that accumulates mutations at a much higher rate would, however, provide adequate information for reading recent population history. That is precisely what mitochondrial DNA (mtDNA) offers.

MtDNA is a relatively new technique to reconstruct family trees. Unlike the DNA in the cell nucleus, mtDNA is located elsewhere in the cell, in compartments that produce the energy needed to keep cells alive. Unlike an individual's nuclear genes, which are a combination of genes from both parents, the mitochondrial genome comes only from the mother. Because of this maternal mode of inheritance, there is no recombination of maternal and paternal genes, which sometimes blurs the history of the genome as read by geneticists. Potentially, therefore, mtDNA offers a powerful way of inferring population history.

MtDNA can yield two major conclusions relevant for our topic: the first addresses the depth of our genetic routes, the second the possible location of the origin of anatomically modern humans.

Multiregional model:

 * extensive genetic variation, implying an ancient origin, going back at least a million years (certainly around 1.8 million years ago);
 * no population would have significantly more variation than any other. Any extra variation the African population might have had as the home of Homo erectus would have been swamped by the subsequent million years of further mutation.

Replacement model:

 * limited variation in modern mtDNA, implying a recent origin;
 * African population would display most variation.

Results

 * 1) If modern populations derive from a process of long regional continuity, then mtDNA should reflect the establishment of those local populations, after 1.8 million years ago, when populations of Homo erectus first left Africa and moved into the rest of the Old World. Yet the absence of ancient mtDNA in any modern living population gives a different picture. The amount of genetic variation throughout all modern human populations is surprisingly small, and implies therefore a recent origin for the common ancestor of us all.
 * 2) Although genetic variation among the world's population is small overall, it is greatest in African populations, implying they are the longest established.
 * 3) If modern humans really did evolve recently in Africa, and then move into the rest of the Old World where they mated with established archaic sapiens, the resulting population would contain a mixture of old and new mtDNA, with a bias toward the old because of the relative numbers of newcomers to archaic sapiens. Yet the evidence does not seem to support this view.

The argument that genetic variation among widely separated populations has been homogenized by gene flow (interbreeding) is not tenable any more, according to population geneticists.

Intermediate Model
Although these two hypotheses dominate the debate over the origins of modern humans, they represent extremes; and there is also room for several intermediate models.
 * One hypothesis holds that there might have been a single geographic origin as predicted by replacement model, but followed by migrations in which newcomers interbred with locally established groups of archaic sapiens. Thus, some of genes of Neanderthals and archaic H. sapiens may still exist in modern populations;
 * Another hypothesis suggests that there could have been more extensive gene flow between different geographic populations than is allowed for in the multi-regional model, producing closer genetic continuity between populations. Anatomically modern humans evolved in Africa, and then their genes diffused to the rest of the world by gene flow, not by migration of anatomically modern humans and replacement of local peoples.

In any case the result would be a much less clearcut signal in the fossil record.

Southwest Asia
Neanderthal fossils have been found in Israel at several sites: Kebara, Tabun, and Amud. For many years there were no reliable absolute dates. Recently, these sites were securely dated. The Neanderthals occupied Tabun around 110,000 years ago. However, the Neanderthals at Kebara and Amud lived 55,000 to 60,000 years ago. By contrast, at Qafzeh Cave, located nearby, remains currently interpreted as of anatomically modern humans have been found in a layer dated to 90,000 years ago.

These new dates lead to the surprising conclusion that Neanderthals and anatomically modern humans overlapped - if not directly coexisted - in this part of the world for a very long time (at least 30,000 years). Yet the anatomical evidence of the Qafzeh hominid skeletons reveals features reminiscent of Neanderthals. Although their faces and bodies are large and heavily built by today's standards, they are nonetheless claimed to be within the range of living peoples. Yet, a recent statistical study comparing a number of measurements among Qafzeh, Upper Paleolithic and Neanderthal skulls found those from Qafzeh to fall in between the Upper Paleolithic and Neanderthal norms, though slightly closer to the Neanderthals.

Portugal
The Lagar Velho 1 remains, found in a rockshelter in Portugal dated to 24,500 years ago, correspond to the complete skeleton of a four-year-old child.

This skeleton has anatomical features characteristic of early modern Europeans:
 * prominent chin and certain other details of the mandible;
 * small front teeth;
 * characteristic proportions and muscle markings on the thumb;
 * narrowness of the front of pelvis;
 * several aspects of shoulder and forearm bones.

Yet, intriguingly, a number of features also suggest Neanderthal affinities:
 * the front of the mandible which slopes backward despite the chin;
 * details of the incisor teeth;
 * pectoral muscle markings;
 * knee proportions and short, strong lower-leg bones.

Thus, the Lagar Velho child appears to exhibit a complex mosaic of Neanderthal and early modern human features. This combination can only have resulted from a mixed ancestry; something that had not been previously documented for Western Europe. The Lagar Velho child is interpreted as the result of interbreeding between indigenous Iberian Neanderthals and early modern humans dispersing throughout Iberia sometime after 30,000 years ago. Because the child lived several millennia after Neanderthals were thought to have disappeared, its anatomy probably reflects a true mixing of these populations during the period when they coexisted and not a rare chance mating between a Neanderthal and an early modern human.

Population dispersal into Australia/Oceania
Based on current data (and conventional view), the evidence for the earliest colonization of Australia would be as follows:
 * archaeologists have generally agreed that modern humans arrived on Australia and its continental islands, New Guinea and Tasmania, about 35,000 to 40,000 years ago, a time range that is consistent with evidence of their appearance elsewhere in the Old World well outside Africa;
 * all hominids known from Greater Australia are anatomically modern Homo sapiens;
 * the emerging picture begins to suggest purposeful voyaging by groups possessed of surprisingly sophisticated boat-building and navigation skills;
 * the only major feature of early Greater Australia archaeology that does NOT fit comfortably with a consensus model of modern human population expansion in the mid-Upper Pleistocene is the lithic technology, which has a pronounced Middle, rather than Upper, Paleolithic cast.

Over the past decade, however, this consensus has been eroded by the discovery and dating of several sites:
 * Malakunanja II and Nauwalabila I, located in Arnhem Land, would be 50,000 to 60,000 years old;
 * Jinmium yielded dates of 116,000 to 176,000 years ago.

Yet these early dates reveal numerous problems related to stratigraphic considerations and dating methods. Therefore, many scholars are skeptical of their value.

If accurate, these dates require significant changes in current ideas, not just about the initial colonization of Australia, but about the entire chronology of human evolution in the early Upper Pleistocene. Either fully modern humans were present well outside Africa at a surprisingly early date or the behavioral capabilities long thought to be uniquely theirs were also associated, at least to some degree, with other hominids.

As a major challenge, the journey from Southeast Asia and Indonesia to Australia, Tasmania and New Guinea would have required sea voyages, even with sea levels at their lowest during glacial maxima. So far, there is no archaeological evidence from Australian sites of vessels that could have made such a journey. However, what were coastal sites during the Ice Age are mostly now submerged beneath the sea.

Summary
Overall the evidence suggested by mitochondrial DNA is the following:
 * the amount of genetic variation in human mitochondrial DNA is small and implies a recent origin for modern humans;
 * the African population displays the greatest amount of variation; this too is most reasonably interpreted as suggesting an African origin.


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Introduction to Paleoanthropology/MiddlePaleolithic Technology

Stone tool industry
Neanderthals and their contemporaries seem to have been associated everywhere with similar stone tool industries, called the Mousterian (after Le Moustier Cave in France). Therefore no fundamental behavioral difference is noticeable. The implication may be that the anatomical differences between Neanderthals and near-moderns have more to do with climatic adaptation and genetic flow than with differences in behavior.

Archaeological sites are dominated by flake tools. By contrast, Acheulean sites are dominated by large handaxes and choppers. Handaxes are almost absent from Middle Paleolithic sites. Oldowan hominids used mainly flake tools as well. However, unlike the small, irregular Oldowan flakes, the Middle Paleolithic hominids produced quite symmetric, regular flakes using sophisticated methods.

The main method is called the Levallois and it involves three steps in the core reduction:
 * 1) the flintknapper prepares a core having one precisely shaped convex surface;
 * 2) then, the knapper makes a striking platform at one end of the core;
 * 3) finally, the knapper hits the striking platform, knocking off a flake whose shape is determined by the original shape of the core.

Mousterian tools are more variable than Acheulean tools. Traditionally tools have been classified into a large number of distinct types based on their shape and inferred function. Among the most important ones are:
 * points;
 * side scrapers, flake tools bearing a retouched edge on one or both sides;
 * denticulates, flake tools with a succession of irregular adjacent notches on one or both sides.

Francois Bordes found that Middle Paleolithic sites did not reveal a random mix of tool types, but fell into one of four categories that he called Mousterian variants. Each variant had a different mix of tool types. Bordes concluded that these sites were the remains of four wandering groups of Neanderthals, each preserving a distinct tool tradition over time and structured much like modern ethnic groups.

Recent studies give reason to doubt Bordes' interpretation. Many archaeologists believe that the variation among sites results from differences in the kinds of activity performed at each locality. For example, Lewis Binford argued that differences in tool types depend on the nature of the site and the nature of the work performed. Some sites may have been base camps where people lived, while others may have been camps at which people performed subsistence tasks. Different tools may have been used at different sites for woodworking, hide preparation, or butchering prey.

Recently, however, microscopic studies of wear patterns on Mousterian tools suggest that the majority of tools were used mainly for woodworking. As a result, there seems to be no association between a tool type (such as a point or a side-scraper) and the task for which it was used.

Microscopic analyses of the wear patterns on Mousterian tools also suggest that stone tools were hafted, probably to make spears.

Mousterian hominids usually made tools from rocks acquired locally. Raw materials used to make tools can typically be found within a few kilometers of the site considered.

Subsistence Patterns
Neanderthal sites contain bones of many animals alongside Mousterian stone tools. European sites are rich in bones of red deer, fallow deer, bison, aurochs, wild sheep, wild goat and horse, while eland, wildebeest, zebra are found often at African sites. Archaeologists find only few bones of very large animals such as hippopotamus, rhinoceros and elephant, even though they were plentiful in Africa and Europe.

This pattern has provoked as much debate at similar ambiguity as for earlier hominids, regarding the type of food procurement responsible for the presence of these bones: hunting or scavenging.

Several general models have be offered to explain the Mousterian faunal exploitation:

Obligate Scavenger Model
Some archaeologists (such as Lewis Binford) believe that Neanderthals and their contemporaries in Africa never hunted anything larger than small antelope, and even these prey were acquired opportunistically, not as a result of planned hunts. Any bones of larger animals were acquired by scavenging. As evidence in support of this view, the body parts which dominate (skulls and foot bones) are commonly available to scavengers. Binford believes that hominids of this period did not have the cognitive skills necessary to plan and organize the cooperative hunts necessary to bring down large prey. Mousterian hominids were nearly as behaviorally primitive as early Homo.

Flexible Hunter-Scavenger Model
Other scientists argue that Neanderthals likely were not obligate scavengers, but that during times when plant foods were abundant they tended to scavenger rather than hunt. At other times, when plant foods were less abundant, Neanderthals hunted regularly. Their interpretation is of a flexible faunal exploitation strategy that shifted between hunting and scavenging.

Less-Adept Hunter Model
Other scientists believe that Neanderthals were primarily hunters who regularly killed large animals. But they were less effective hunters than are modern humans. They point out that animal remains at Mousterian sites are often made up of one or two species:
 * For example, at Klasies River, vast majority of bones are from eland.

The prey animals are large creatures, and they are heavily overrepresented at these sites compared with their occurrence in the local ecosystem. It is hard to see how an opportunistic scavenger would acquire such a non-random sample of the local fauna. One important feature of this model is that animal prey hunted such as eland are not as dangerous prey as buffalo. Middle Paleolithic hominids were forced to focus on the less dangerous (but less abundant) eland, because they were unable to kill the fierce buffalo regularly.

Fully Adept Hunter Model
Finally some scientists argue that scavenging was not a major component of the Middle Paleolithic diet and there is little evidence of a less effective hunting strategy. Skeletal element abundance and cut mark patterning would be consistent with hunting.

Overall, there is currently no evidence that Middle Paleolithic hominids differed from Upper Paleolithic hominids in scavenging or hunting, the most fundamental aspect of faunal exploitation. The differences that separate Middle Paleolithic hominids from modern hominids may not reside in scavenging versus hunting or the types of animals that they pursued. Differences in the effectiveness of carcass use and processing, with their direct implications for caloric yield, may be more important.

Neanderthals lacked sophisticated meat and fat storage technology, as well as productive fat rendering technology. At a minimum, the lack of storage capabilities and a lower caloric yield per carcass have forced Neanderthals to use larger foraging ranges to increase the likelihood of successful encounters with prey.

Cannibalism
Marks on human bones from Middle Paleolithic can be the result of two phenomena: violence and cannibalism.

Violence
Violence can be recognized on bone assemblages by: Evidence for violence in the Middle Paleolithic is extremely rare.
 * marks of weapons;
 * cutmarks on skull produced by scalping;
 * removal of heads and hands as trophies;
 * breakage of faces;
 * much less "body processing" than in case of cannibalism.

Body processing and cannibalism
By contrast, evidence of body processing and cannibalism is becoming more widespread at different times and in different geographical areas.

Chronology

 * Lower Paleolithic
 * Sterkfontein (South Africa): cannibalism
 * Bodo cranium (Ethiopia): cannibalism
 * Atapuerca (Spain): cannibalism

 * Middle Paleolithic (Neanderthals)
 * Krapina (Croatia): body processing
 * Moula-Guercy (France): cannibalism
 * Marillac (France): cannibalism
 * Combe-Grenal (France): cannibalism

 * Middle Paleolithic (Homo sapiens idaltu)
 * Herto (Ethiopia): body processing

 * Upper Paleolithic (with Neanderthals)
 * Vindija (Croatia): cannibalism
 * Zafarraya (Spain): cannibalism

 * Neolithic
 * Fontbrégoua (France): cannibalism

Criteria
Criteria required for a "minimal taphonomic signature" of cannibalism: These criteria must be found on both hominid and ungulate remains. Finally the types of bones usually broken are the crania and limb bones.
 * breakage of bones (to get at marrow and brain);
 * cut marks suggesting butchery;
 * so-called anvil abrasions left where a bone has rested on a stone anvil whilst it is broken with a hammer stone;
 * burning (after breakage and cutting);
 * virtual absence of vertebrae (crushed or boiled to get at marrow and grease);
 * "pot polishing" on the ends of bones which have been cooked and stirred in a clay pot.

Patterns
Different behavioral patterns toward the dead among Middle Paleolithic Neanderthals:
 * Cannibalism: Moula-Guercy
 * Human individuals defleshed and disarticulated.
 * Bones smashed for marrow and brain.
 * Mortuary practices with body processing: Krapina, Herto
 * Postmortem processing of corpses with stone tools, probably in preparation for burial of cleaned bones.
 * No evidence of marrow processing.
 * Mortuary practices without body processing: Southwest Asia (Amud, Kebara, Shanidar)
 * Intentional burials; dead bodies placed carefully in burial pits with tools and grave goods.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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User talk:Kundalini24

I have designed and developed a method of learning English language within four months.

title: User talk:Kundalini24


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Talk:Introduction to Paleoanthropology/Darwinian Thought

For the next draft, the death of the "fixity of species" idea needs to be clarified. Section 1.1 says that LeClerc and Lamark moved beyond it, but the next section gives Darwin the credit for it. (The first Darwin section was very readably put together, by the way.)

It's not really clear why the three Selection bits (Individual, Directional, and Stabilizing) are subsections under "Advantages and Disadvantages".

In Darwin's day, the idea that natural selection could change a chimpanzee into a human... was unthinkable. -- I think this should be revised to avoid mentioning the chimpanzee-human thing. Although you do state "apelike creature" in the next paragraph, there are enough people who will seize on any chance to claim (incorrectly) that scientists think we descended from chimpanzees that it's best just not to give them any opening in the first place.

But only a few endorsed Darwin's view that major changes occur through the accumulation of small variations. -- Should the eye dilemma be mentioned here, or would it be unnecessary detail? (PBS Evolution of the Eye)

Some resources:

Darwiniana and Evolution

Evolutionary Classics

Early Theories of Evolution

Alfred Russel Wallace is gapingly missing from this discussion. --Bedawyn 20:55, 2 Oct 2004 (UTC)


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Modern Physics/Potential Momentum

Potential Momentum
In classical physics we know that kinematics can often be described by a potential energy alone. Now we've seen that in relativity the energy is just the temporal component of the momentum 4-vector, so we should expect the same of the potential energy. To see how this works, we'll reason by analogy from the classical case.

For a free, non-relativistic particle of mass m, the total energy E equals the kinetic energy K and is related to the momentum Π of the particle by

 * $$ E = K = \frac{| \boldsymbol{\Pi} |^2}{2m} \qquad \mbox{(free, non-relativistic)} . $$

In the non-relativistic case, the momentum is Π= mv, where v is the particle velocity.

If the particle is not free, but is subject to forces associated with a potential energy U(x,y,z), then the equation must be modified to account for the contribution of U to the total energy:

 * $$ E - U = K = \frac{| \boldsymbol{\Pi} |^2}{2m} \qquad \mbox{(non-free, non-relativistic)} . $$

The force on the particle is related to the potential energy by

 * $$ \mathbf{F} = - \left( \frac{\partial U}{\partial x}, \frac{\partial U}{\partial y} , \frac{\partial U}{\partial z} \right) . $$

For a free, relativistic particle, we have
 * $$ E = ( | \boldsymbol{\Pi} |^2 c^2 + m^2 c^4 )^{1/2} \qquad \mbox{(free, relativistic)} . $$

The obvious way to add forces to the relativistic case is by rewriting this equation with a potential energy:

 * $$ E - U = ( | \boldsymbol{\Pi} |^2 c^2 + m^2 c^4 )^{1/2} \qquad \mbox{(incomplete!)} . $$

However $$\boldsymbol\Pi = (\Pi, E/c)$$ is a four-vector, so an equation with something subtracted from just one of the components of this four-vector is not relativistically invariant. In other words, this equation doesn't obey the principle of relativity, and therefore cannot be correct!

How can we fix this problem? One way is to define a new four-vector with U/c being its timelike part and some new vector Q being its spacelike part:
 * $$ \underline{Q} \equiv ( \mathbf{ Q}, U/c) \qquad \mbox{(potential four-momentum)} . $$

We then subtract Q from the momentum Π. When we do this, equation (13.5) becomes
 * $$ E - U = ( | \boldsymbol{\Pi} - \mathbf{ Q}|^2 c^2 + m^2 c^4 )^{1/2} \qquad \mbox{(non-free, relativistic)} . $$

The quantity Q is called the potential momentum and Q is the potential four-momentum.

If |Π-Q| is much smaller than mc, this becomes approximately

 * $$E = mc^2 + \frac{1}{2m}\left( \boldsymbol{\Pi} - \mathbf{Q} \right)^2 $$

This expression for the energy has the same form as the Hamiltonian we looked at for classical velocity dependent forces, so we know it predicts a force perpendicular to the velocity, when the condition is met. It turns out to be perpendicular even when the condition is met.

In classical physics the potential momentum is an optional extra. In relativity it is a necessary part of any potential field.

Some additional terminology is useful. We define
 * $$ \mathbf{ p} \equiv \boldsymbol{\Pi} - \mathbf{ Q} \qquad \mbox{(kinetic momentum}) $$

as the kinetic momentum since in the classical case it reduces to mv. In order to avoid confusion, we rename Π the total momentum. Thus, the total momentum equals the kinetic plus the potential momentum, in analogy with energy.

title: Modern Physics/Potential Momentum


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Cookbook:Chicken Cabbage Salad

This chicken cabbage salad is a very easy way to make a tasty cabbage salad. It works well as both a side salad or a main dish.

Ingredients

 * 1 head cabbage
 * 1 bunch of cilantro
 * 1 bunch of green onions
 * ½ cup slivered almonds, toasted
 * ½ cup sunflower seeds
 * 2 packages of ramen noodles, Oriental flavor
 * 2 cooked chicken breasts
 * ½ cup of vegetable or canola oil
 * ½ cup of rice vinegar
 * 1 packet of Oriental flavoring (from one of the ramen packages)
 * Salt to taste
 * Pepper to taste
 * Sugar to taste

Procedure

 * 1) Chop the cabbage, cilantro leaves, and green onion until it is at an even consistency among the three. Mix together.
 * 2) Add the almonds and sunflower seeds.
 * 3) Break up the ramen noodles and place in the salad.
 * 4) Mix oil, rice vinegar, and flavoring. This is now your dressing.
 * 5) Pour dressing over salad, and add salt and pepper to taste
 * 6) Leave salad to sit and absorb flavor for an hour for best taste.

Notes, tips, and variations

 * Vegetarian chicken patties can be used to replace the chicken breasts
 * Cooked and cooled ramen noodles can be used for those who don't like crunchy noodles in their salad.
 * Try browning the noodles a nuts in a little butter, let them cool, and sprinkle on salad.

title: Cookbook:Chicken Cabbage Salad


text: Template:Bookshelves

title: Template:Bookshelves


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Modern Physics/The Law of Gravitation

Law of Gravitation

 * Aubhro Sengupta Spring 2020*

How do we calculate the force of gravity on an object? It seems like a simple enough task.
 * $$ F_g = g * m $$

However, this is only applicable when we want to calculate the force of gravity from earth on an object on earth. What if we want to calculate the force of gravity of an asteroid in space from another asteroid, or the force of gravity on a space craft from the sun. This is where universal gravitation comes in.

Of Newton's accomplishments, the discovery of the universal law of gravitation ranks as one of his greatest. Imagine two masses, M1 and M2, separated by a distance r. The gravitational force has the magnitude

 * $$ F_g = G \frac{M_1 M_2}{r^2} $$

where G is the gravitational constant:

 * $$G \approx 6.67 \times 10^{-11} \frac{m^3}{kg \cdot s^2}$$

The force is always attractive, and acts along the line joining the center of the two masses.

Lets notice a couple things here. First of all, since gravity is a force, it is a vector. The formula described above only gives us it's magnitude. What is the direction? Well depends on which force of gravity we are talking about. Since there are 2 objects here, M1 and M2, there are also two forces, the force of gravity on M1 by M2 and the force of gravity on M2 by M1. The magnitude of both forces are the same but the directions are opposite one another. This is actually a case of Newton's second law, as both forces are equal and opposite.

Notice that the ``r`` is squared in the bottom of the fraction. This tells us that not only does gravity get weaker as ``r`` increases, but it gets much weaker as ``r`` increases. This is why although technically all objects in the universe attract every other object through gravity, we can often disregard the force as it is negligible.

Vector Notation
Let's say that we have two masses, M and m, separated by a distance r, and a distance vector R. The relationship between R and r is given by:

 * $$|\vec{\mathbf{R}}| = r$$

We will also change our force into a force vector, acting in the direction of R:

 * $$\vec{F}_g = G \frac{M_1 M_2}{r^2} \cdot \frac{\vec{\mathbf{R}}}{r}$$

And this gives us our final vector equation:

 * $$\vec{F}_g = G \frac{M_1 M_2 \vec{\mathbf{R}}}{r^3} $$

Notice that since the ratio between R and r is normalized, the addition of these terms does not alter the equation, only the direction in which the force is acting.

title: Modern Physics/The Law of Gravitation


text:
Cookbook:Salting

Salting is a method of preserving food, that was more common before modern refrigeration.

Salting preserves food by drawing water out of the food, preventing bacteria growing and spoiling the food.

There are two methods of salting food:

Dry Curing

The food is surrounded in salt and left in a cool dry place. As water will be drawn out into the salt it may be necessary to pour the accumulated liquid out. Wet Curing

A brine is prepared by dissolving salt in water, the food is then placed in the brine and left in a cool dry place. It is possible to introduce new flavours to the food by adding spices to the brine, for example juniper berries or peppercorns.

Depending on how much salt is used the food could last for a few months to a few years, and the technique adds flavor as well, though some do not like the taste of salted foods. Salted food is very salty and may need to be reconstituted, to reintroduce water and remove some of the salt.

Some popular salted foods are Lox and the less salty (and thus less preserved) counterpart Nova Lox.

title: Cookbook:Salting


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Cookbook:Salmon

| Basic foodstuffs | Seafood | Fish

Salmon is a very popular fish, being large and high in omega-3 fatty acids. Canned salmon is high in calcium because the bones have been softened and are eaten with the meat. Salmon is particularly popular in the American Jewish community. The eggs are sometimes eaten as a caviar substitute.

The line-caught variety is especially prized and expensive. Much like flamingos, wild salmon gain their pink or red color from the krill (small shrimp-like animals) that they eat. Color differences indicate food source differences. Farm-raised salmon are artificially colored by feeding them a dye that tends to remain in flesh. The dye has been shown to remain in humans, including the retina, which can be damaging to eyesight. Farm-raised salmon taste somewhat like corn, likely due to the feed being used. Farm-raised salmon can be recognized by the wider fat-filled or goo-filled gaps between the flakes of meat.

When purchasing fish, freshness is important. The fish should not have a fishy smell, which actually comes from bacteria decomposing the fish. If purchasing whole fish, the eyes should be clear. Frozen-at-sea fish are often the freshest choice available.

Trout may be substituted for salmon.

Types of Salmon Products

 * Lox - Salted salmon.
 * Smoked Salmon

Recipes with Salmon

 * Gravlax
 * Salmon fried rice
 * Honey Mustard Salmon
 * Plank-Grilled Salmon
 * Maple Syrup Planked Salmon
 * Salmon with Rice and Sauce

 * Canned Salmon Recipes by Alaska Packers' Association, 1900 e-book with color illustrations, available from Internet Archive

In culture
In Norse mythology there is a story about Loki, the god of mischief and strife: In order to escape punishment by the other gods for trying to trick the blind god Hod into killing Baldur, the god of beauty and light, Loki jumped into a river and transformed himself into a salmon. The other gods tried to catch him in a net. As Loki was trying to escape by leaping over the net, Thor grabbed him by the tail. This is why the salmon's tail is tapered today.

The fish with the tapered tail lives an interesting life. Born in fresh water, it migrates to the ocean and returns to fresh water to reproduce. It is said that later in their lives, salmon return to exactly the same spot where they were born. This could be the reason why the salmon tastes so fancy - this interesting lifestyle may have an effect on the flavor of the fish. And if you want your salmon dish to taste even more intense, use smoked salmon instead of fresh.

title: Cookbook:Salmon


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Cookbook:Holland Tea Cakes

| Holiday Recipes | Dessert

Holland tea cakes are simple flat cookies. They are easy and quick to make. They are traditionally Christmas cookies but are good for any time. They last for a long time, so if you make too many they can be saved.

Ingredients

 * 1 cup (240 g) white granulated sugar
 * 1 stick butter, preferably melted
 * 2 eggs, separated
 * 2 cups (280 g) flour
 * 1–2 teaspoons cinnamon (or to taste)
 * Colored sugar or nuts for topping

Procedure

 * 1) Preheat oven to 350°F (180°C).
 * 2) Mix the butter and sugar until completely combined. Mix in the egg yolk, then the flour and cinnamon (preferably by hand, though this all can be done in a mixer if you want).
 * 3) Pour batter into a cookie pan. Use the palm of your hand to spread and smooth it over the whole pan (this is the hardest part).
 * 4) Brush on leftover egg white. Scatter your desired toppings evenly over the batter.
 * 5) Bake in preheated oven until cookies are golden brown (about 20 minutes). Remove, and let cool slightly.
 * 6) Before they get too cool, cut them into small 1-inch (2.5 cm) squares.

Notes, tips, and variations

 * Egg substitutes can be used in place of the egg yolk, but you still need egg white for the topping.

title: Cookbook:Holland Tea Cakes


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User:MaxPolun

I'm a college student at drexel university, studing physics. I live in Philadelphia.

I have so far added a few recipies to the cookbook, but am looking foreward to working on some more technical modules as well.

title: User:MaxPolun


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Introduction to Paleoanthropology/Evolution/Food Production

Food Production
The ways in which humans procure resources are not unlimited. Essentially, there are five major procurement patterns practiced in the world today:
 * Food collection
 * hunting and gathering
 * Food production
 * extensive agriculture
 * intensive agriculture
 * pastoralism
 * industrialism

Food Collection: Hunting and Gathering
People who practice a hunting and gathering subsistence strategy simply rely on whatever food is available in their local habitat, for the most part collecting various plant foods, hunting wild game, and fishing (where the environment permits).

They collect but they do not produce any food. For example, crops are not cultivated and animals are not kept for meat or milk. Hunters and gathers do and did modify the landscape to increase the amount of available food. One of the main ways hunters and gatherers modified their environment was through the use of burning. Today, only about 30,000 people make their living in this fashion.

Cultures of agriculturalists, having larger ecological footprints have pushed most hunters and gatherers out of the areas where plant food and game is abundant into the more marginal of the earth: the Arctic, arid deserts, and dense tropical rain forests.

Food Production: Terminology
Food Production: General term which covers types of domestication involving both plants and animals, each of which requires radically different practices.

Cultivation: Term refers to all types of plant culture, from slash-and-burn to growing crop trees. Terminological distinctions within the term cultivation are based on types on gardens maintained and means with which they are cultivated. Example: distinction between horticulture and agriculture

 * Horticulture: Refers to smaller-scale, garden-based cultivation, usually of a mixed variety of plant species, often with relatively simple tools.

 * Agriculture: This practice requires tools of greater complexity or higher energy in their manufacture and use, such as animal traction, etc.

 * Slash-and-burn: Strategy, normally horticultural, in which forest or bush land is cleared by chopping and burning the less useful wood species, planting in the ashes, harvesting for several years and then moving on to a new plot of land.

 * "Non-domestication" vs. "pre-domestication" cultivation: Cultivation of crops in some cases does not induce domestication. Example of such methods common among hunter-gatherers: beating the plants or reaping them when they are ripe. Therefore called "non-domestication cultivation." Other methods can induce the domestication of wild-type crops: uprooting or reaping grasses not ripe or nearly ripe using sickles. Therefore called "pre-domestication cultivation"

Animal Husbandry: Term refers to all types of animal rearing practices, ranging from chicken to cattle.

 * Pastoralism: Term normally used to refer to subsistence-oriented livestock production in which some animals or animal products are sold or bartered for food or other commodities, but family reproduction relies largely on the herds. Animals featured in this way of life vary according to regions and include cattle, sheep, goats, camels, horses.

Southwest Asia
Credited with domesticating: Dog, pig, goat, sheep, wheat, barley, oat, peas, lentils, apples.
 * Mobile Hunter-Gatherers
 * Sedentary hunter-gatherers
 * Sedentary farming communities

China
Credited with domesticating: Rice
 * Mobile Hunter-Gatherers
 * Sedentary hunter-gatherers
 * Sedentary farming communities

Africa
Credited with domesticating: Sorghum, cattle

Mesoamerica
Credited with domesticating: Maize (corn), squash, pumpkin, sunflower, turkey
 * Mobile hunter-gatherers
 * Small mobile farming communities
 * Sedentary farming communities


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High School Mathematics Extensions/Supplementary/Partial Fractions

Introduction
Before we begin, consider the following:
 * $$\frac{1}{1\times2}+\frac{1}{2\times3}+\frac{1}{3\times4}......+\frac{1}{99\times100}$$

How do we calculate this sum? At first glance it may seem difficult, but if you use variables instead of numbers each term in the sum above would take the form:
 * $$\frac{1}{n\times(n + 1)}$$

which you can rewrite as
 * $$\frac{(n + 1) - n}{n\times(n + 1)} = \frac{(n+1)}{n\times(n + 1)}-\frac{n}{n\times(n + 1)} = \frac{1}{n}-\frac{1}{n+1}$$

Thus we can rewrite the original problem as follows:
 * $$(\frac{1}{1}-\frac{1}{2})+(\frac{1}{2}-\frac{1}{3})+(\frac{1}{3}-\frac{1}{4})+......+(\frac{1}{99}-\frac{1}{100})$$

Regrouping:
 * $$\frac{1}{1}+(-\frac{1}{2} + \frac{1}{2})+(-\frac{1}{3}+\frac{1}{3})+....+(-\frac{1}{99}+\frac{1}{99})-\frac{1}{100})$$

So all terms except the first and the last cancel out, yielding:
 * $$\frac{1}{1\times2}+\frac{1}{2\times3}+\frac{1}{3\times4}......+\frac{1}{99\times100}=1-\frac{1}{100}=\frac{99}{100}$$

Believe it or not, we've just done partial fractions!

Partial fractions is a method of breaking down complex fractions which involve products into sums of simpler fractions.

General method
So, how do we do partial fractions? Look at the example below:
 * $$\frac{4z-5}{z^2-3z+2}$$

Factorizing the denominator:
 * $$\frac{4z-5}{(z-1)(z-2)}$$

Then we suppose we can break it down into two fractions with denominator (z - 1) and (z - 2) respectively, let their numerators be a and b:
 * $$\frac{4z-5}{(z-1)(z-2)} = \frac{a}{z-1}+\frac{b}{z-2}$$

Multiplying by (z - 1)(z - 2):
 * $$4z-5 = a(z-2) + b(z-1)$$

 * $$4z-5 = az-2a+bz-b$$

 * $$4z-5 = (a+b)z-(2a+b)$$

Therefore by matching coefficients of like power of z, we have:

\begin{cases} a+b=4 & (\text{A}) \\ 2a+b=5 & (\text{B}) \end{cases} $$

Furthermore:

(\text{B})-(\text{A}) : a = 1 \to b = 3 $$

Therefore
 * $$\frac{4z-5}{z^2-3z+2}=\frac{1}{z-1}+\frac{3}{z-2}$$

Generally speaking, this method only works with proper fractions. Numerators with greater exponents than their denominators need to be divided first.

1. Can you find an equivalent expression to $$y = \frac{3p-21}{(p-5)p-14}$$ that is defined for $$y = \frac{1}{3}$$ ? TIP: Here, "defined" means having some value p for which the equation yields 1/3.

Power factors
On the last section we have talked about factorizing the denominator, and have each factor as the denominator of each term. But what happens when there are repeating factors? Can we apply the same method? See the example below:
 * $$\frac{4x-1}{(x+2)^2(x-1)}$$

Other than the method suggested above, we would like to use another approach to handle the problem. We first leave out some factor to make it into non-repeated form, do partial fraction on it, then multiply the factor back, then apply partial fraction on the 2 fractions.
 * $$\frac{1}{x+2} \times \frac{4x-1}{(x+2)(x-1)}$$

Partial fraction on the latter part:
 * $$\frac{4x-1}{(x+2)(x-1)} = \frac{a}{x+2} + \frac{b}{x-1}$$

Multiplying by (x + 2)(x - 1):
 * $$4x-1 = a(x-1) + b(x+2)$$

 * $$4x-1 = a(x-1)+b(x+2)$$

 * $$4x-1 \equiv (a+b)x + (2b-a)$$

By matching coefficients of like power of x, we have:

\begin{cases} a+b = 4 & (\text{A}) \\ 2b-a = -1 & (\text{B}) \end{cases} $$

Substitute a = 4 - b into (B),
 * $$2b-(4-b) = -1$$

Hence b = 1 and a = 3.

We carry on:
 * $$\frac{1}{x+2} \times \left ( \frac{3}{x+2} + \frac{1}{x-1} \right )$$

 * $$\frac{3}{(x+2)^2} + \frac{1}{(x+2)(x-1)}$$

Now we do partial fraction once more:
 * $$\frac{1}{(x+2)(x-1)} = \frac{a}{x+2} + \frac{b}{x-1}$$

Multiplying by (x + 2)(x - 1):
 * $$1 = a(x-1) + b(x+2)$$

 * $$1 = (a+b)x + (2b-a)$$

 * $$0x + 1 = (a+b)x + (2b-a)$$

By matching coefficients of like power of x, we have:

\begin{cases} a+b = 0 & (\text{A}) \\ 2b-a = 1 & (\text{B}) \end{cases} $$

Substitute a = -b into (B), we have:
 * $$2b-(-b) = 1$$

Hence b = 1/3 and a = -1/3.

So finally,
 * $$\frac{4x-1}{(x+2)^2(x-1)} = \frac{3}{(x+2)^2} - \frac{1}{3(x+2)} + \frac{1}{3(x-1)}$$

2. What about $$\frac{3q+2}{(\frac{3}{2}q^2+\frac{3}{2}q-6)q-6}$$ ?

Quadratic factors
We should always try to factor the denominator, for the sake of simplicity. There are some cases, though, in which factoring a polynomial leads to complex coefficients. Since these do anything but simplify our task, we shall leave the polynomial as it is. That is, as irreducible quadratic factors:
 * $$\frac{7x^2+22x+25}{x^3+3x^2+2x+6} = \frac{7x^2+22x+25}{(x+3)(x^2+2)}$$

When dealing with the quadratic factor, we should use the following partial fraction:
 * $$\frac{bx + c}{x^2+2}$$

Leading to:
 * $$\frac{7x^2+22x+25}{(x+3)(x^2+2)} = \frac{a}{x+3} + \frac{bx + c}{x^2+2}$$

Multiplying by (x + 3)(x^2 + 2):
 * $$7x^2+22x+25 = a(x^2+2) + (bx + c)(x+3)$$

 * $$7x^2+22x+25 = a(x^2+2) + (bx + c)(x+3)$$

 * $$7x^2+22x+25 = (a+b)x^2+(3b+c)x+(2a+3c)$$

By matching coefficients of like power of x, we have:

\begin{cases} a+b = 7 & (\text{A}) \\ 3b+c = 22 & (\text{B}) \\ 2a+3c = 25 & (\text{C}) \end{cases} $$

Solving:
 * $$(\text{C})-2(\text{A})-3(\text{B}) = (\text{C})-2(\text{A})-3(\text{B})$$

 * $$(2a+3c)-2(a+b)-3(3b+c) = 25 - 2(7) - 3(22)$$

 * $$-11b = -55$$

Therefore b = 5, a = 2 and c = 7.

Finally:
 * $$\frac{7x^2+22x+25}{(x+3)(x^2+2)} = \frac{2}{x+3} + \frac{5x + 7}{x^2+2}$$

3. Try breaking down $$\frac{z^2+3z}{z^3 + 1}$$.


text:
Introduction to Paleoanthropology/UpperPaleolithic

Aurignacian
The Aurignacian indicates a tool industry from the Upper Paleolithic in Europe. A tool industry contains standardized tools and production techniques that indicate a shared cultural knowledge. The Aurignacian industry contains blades (long, thin stone flakes), burins (stone chisels for working bone and wood), bone points, as well as the beginning of prehistoric art.

First Discovered
The name is associated with the Aurignac Rockshelter in the Pyrenees in Southwestern France.

Chronology

 * ca. 35,000-27,000 BC

Geography

 * Widespread distribution over Eurasia
 * Siberia (Sungir)

Hominid

 * Modern humans (Homo sapiens)

Material Culture
The tools of the Aurignacian are quite standardized which shows planning and foresight in their creation. In addition, the inclusion of tools to work bone and wood show a wider variety of raw materials being used in tool production.
 * Upper Paleolithic-type lithic industry
 * Aurignacian blades, burins, endscrapers, etc.
 * Bone Tools

Mortuary practices
The Aurignacian period includes definitive elaborate burials with grave goods. Burials can indicate the social status of the deceased as well as the beginning of religious concept associated with life and death. Grace goods provide archaeologists important social and cultural information.

Symbolic Expression
Proliferation of various forms of personal ornaments:
 * perforated animal-teeth;
 * distinctive "bead" forms carved out of bone and mammoth ivory;
 * earliest perforated marine shells

Artistic Expression
Types of evidence:
 * Engraved limestone blocks
 * Animal and human figurines
 * Parietal art

Engraved block characteristics:
 * Stiffness of outlines;
 * Deep incisions;
 * Work executed mainly on limestone slabs or blocks;
 * Sexual symbols realistically represented;
 * Animals (usually heads, forequarters and dorsal lines) extremely crudely rendered;
 * This type of artistic expression limited to southwest France (mainly Dordogne).

Figurine characteristics:
 * Earliest evidence of artwork in the Upper Paleolithic: Geissenklösterle - 37,000-33,000 BC
 * Present in Central Europe, presently Germany
 * Sophisticated and naturalistic statuettes of animal (mammoth, feline, bear, bison) and even human figures
 * Carved from mammoth ivory

First Discovered

 * La Gravette (Dordogne, France)

Chronology

 * ca. 27,000-21,000 BC

Geography

 * Widespread distribution over Eurasia

Major cultural centers

 * Southwest France
 * Northern Italy (Grimaldi)
 * Central Europe (Dolni Vestonice, Pavlov)

Architecture

 * Mammoth huts

Material Culture

 * Upper Paleolithic-type lithic industry
 * Gravette Points, etc.

Other Economic Activities

 * Pyrotechnology
 * Basketry

Complex mortuary practices

 * Dolni Vestonice triple burial

Artistic Expression
Types:
 * Animal figurines
 * Female figurines ("Venuses")
 * Parietal art

Animal figuring characteristics: Animals most frequently depicted are dangerous species (felines and bears), continuing Aurignacian tradition By contrast, Magdalenian animal statuettes from the same region show very different patterns (N=139): Dangerous animals represent only 10% of total
 * In Moravia, 67 animal statuettes recorded:
 * 21 bears
 * 11 small carnivores
 * 9 felines
 * 8 mammoths
 * 6 birds
 * 6 horses
 * 4 rhinoceroses
 * 1 caprid
 * 1 cervid
 * 56 horses, 44 bisons
 * 9 bears,
 * 2 felines,
 * 1 mammoth
 * 2 birds
 * 1 caprid, 1 cervid
 * 5 miscellaneous, 18 indeterminates
 * No rhinoceros

Female figurine characteristics: Widespread distribution over Europe and Russia; except Spain where no evidence of Venuses
 * Raw materials:
 * ivory
 * clay
 * Various types of research performed by anthropologists:
 * technological
 * stylistic
 * details of clothing, ornaments
 * chronological/geographical
 * interpretational
 * Most of baked clay figurines found fragmented
 * Lack of skill or deliberate action? Intentional fracturation through heating process
 * Fragmented figurines were intended products Involved and by-products of ritual ceremonies rather than art objects

Parietal art characteristics: From 21 sites, a list of 47 animals identified:
 * 9 ibexes
 * 9 cervids
 * 7 horses
 * 4 mammoths
 * 3 bovids
 * 1 megaceros
 * 1 salmon
 * 10 indeterminates

Dangerous animals (rhinoceros, bear, lion) depicted during the Gravettian do not constitute more than 11% of determinable animals:
 * 3 times less than in Aurignacian period);
 * yet still higher frequency than during Solutrean and Magdalenian

Strong preponderance of hunted animals, with horse very widely dominant
 * Example: Gargas with a list of 148 animals identified:
 * 36.5% bovids (bison and aurochs)
 * 29% horses
 * 10% ibexes
 * 6% cervids
 * 4% mammoths
 * 8% indeterminates
 * (2 birds, 1 wild boar)
 * No feline, rhinoceros, bear

First Discovered

 * Solutré (NE France)

Chronology

 * ca. 21,000-18,000 BC

Geography

 * Limited distribution over SW France and Iberia

Material Culture

 * Upper Paleolithic-type lithic industry
 * Heat Treatment, Pressure Retouch
 * Solutrean points: bifacially retouched leaf points, shouldered points, etc.
 * burins, endscrapers, etc.

Settlements

 * Some sedentary groups (Fourneau-du-Diable)
 * Long stratigraphic sequences

Human remains

 * Complex mortuary practices:
 * No evidence of burials, but manipulation of dead (e.g., reuse of skull: Le Placard)

Artistic expression
Types:
 * Engraved limestone blocks
 * Engraved Bones
 * Parietal art

Characteristics:
 * Various techniques applied: painting, engraving
 * Distribution and amount of animals represented in tradition of Late Upper Paleolithic: mainly horses and bisons
 * Several novelties from Gravettian:
 * First association of parietal art with occupation sites [Low-relief scupture on blocks detached from walls];
 * Representation of animals in line or opposed

First Discovered

 * La Madeleine (Dordogne, France)

Chronology

 * ca. 19,000-10,000 BC

Geography

 * Widespread distribution over Eurasia

Major cultural centers

 * Southwest France (Charente, Dordogne, Pyrénées)
 * Northeast Spain
 * Central Europe

Material Culture

 * Upper Paleolithic-type lithic industry
 * Magdalenian blades, burins, etc.
 * Rich bone tool industry (harpoons)

Complex mortuary practices

 * Children burials

Artistic expression
Types:
 * Raw Materials: Great diversity (limestone cave walls and slabs, sandstone, shale, bone, ivory, clay, etc.)
 * Techniques: All techniques employed: Engraving, Sculpture, Molding, Cutting, Drawing, Painting
 * Both mobiliary and parietal arts present. Out of about 300 sites with parietal art, 250 are attributed to Magdalenian period.
 * Types of Figurations:
 * Animals (mainly horses and bisons)
 * Humans (male and female)
 * Hands (positive and negative)
 * Signs (dots, lines)


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Physics Study Guide/Electronics

Electronics is the application of electromagnetic (and quantum) theory to construct devices that can perform useful tasks, from as simple as electrical heaters or light bulbs to as complex as the Large Hadron Collider.

;component of electronics

=Electronics=

Introduction
To discuss electronics we need the basic concepts from electricity: charge, current which is flow of charge, and potential which is the potential energy difference between two places. Please make sure these concepts are familiar before continuing.

Circuits
The interest of electronics is circuits. A circuit consists of wires that connect components. Typical components are resistors, voltage sources. In order to maintain a constant electrical current a continued exhaustion of chemical or mechanical energy is required.

A voltaic cell is a common electromotive power source for a circuit. It consists primarily of two plates, a positive copper plate and a negative zinc plate. One must note that the plates are placed in dilute sulfuric acid. Whence a key is switched or the circuit is closed the zinc reacts with the sulfuric in which it is placed in. One may discern that the electromotive force which is then applied to the circuit is believed to be converted from chemical to electrical energy upon the surface of the zinc cell. Whence the E.M.F is converted from chemical to electrical energy the electromotive force travels through the sulfuric acid. However disadvantages occur whence utilizing a voltaic or galvanic cell. Whence the circuit is closed, simultaneously hydrogen bubbles accumulate upon the copper plate surface hence decreasing the total electromotive power source applied to the circuit in question. The resistance with which the electromotive source encounters as it flows form the zinc plate to the copper plate through the dilute sulfuric acid is distinguished as internal resistance. Hence the voltaic cell uses diluted rather than concentrated sulfuric acid so as to reduce the internal resistance present inside of the component which applies the electromotive force to the circuit.

A circuit can be open, when there is a break so that no current can flow, or it can be closed, so that current can flow. These definitions allow us to discuss electronics efficiently.

Direct current and alternating Current
When the Electrons moves through a particular medium in straight without oscillating on their mean position then it is Direct Current. This DC is used in almost every electronical component. Alternating Current on the other hand as the name suggest, the Electrons alter back and forth and hence produces much electrical energy. AC is mainly used to reduce the wastage of electrons and passing much energy at one time.

Ohm's law
If 'V' is Potential Difference applied at two ends of conductor and 'I' is Current flowing through the conductor then 'I' is directly proportional to its 'V'. V = I x R

Kirchoff's laws
Kirchoff's laws generally hold for direct current (DC) circuits, but fail when dealing with changing electric current and voltage such as alternating current (AC) or signal processing in combination with capacitors, inductors, and antennas.

Kirchoff's current law
The sum of all the currents entering and leaving any point in a circuit is equal to zero.
 * $$\sum_{k=1}^n I_k = 0$$

It is based on the assumption that current flows only in conductors, and that whenever current flows into one end of a conductor it immediately flows out the other end.

Kirchoff's voltage law
The sum of all the voltages around the circuit loop is equal to zero.
 * $$\sum_{k=1}^n V_k = 0$$

It is based on the assumption that there is no fluctuating magnetic field linking the closed circuit loop.

Power
p=work done/time taken p=I*V (current * Voltage) Other Equations for P can also be derived using Ohm's Law, such as P = IR^2, because V=IR, which can be plugged in to get P= I * (IR) and another equation being P = V^2/R.

Resistors in series
In a series circuit, resistance increases as more resistors are added.Each resistor makes an addition to the restriction of the flow of charge.The current through the battery is inversely proportional to the total resistance. The equivalent(total) resistance is calculated by adding the resistances together. R$$eq$$=R$$1$$+R$$2$$+R$$3$$+

Resistors in parallel
1/R = 1/R1+1/R2+1/R3+......

Semiconductors
Current is the rate of flow of charge.

$$I$$ = Current [amperes - A]

$$Q$$ = Charge [coulombs - C]

$$T$$ = Time [seconds - s]

howstuffworks.com

Voltage is equal to current multiplied by resistance

Power is equal to the product of voltage and current

Electronics is the flow of current through semiconductor devices like silicon and germanium.

Semiconductor devices are those which behave like conductors at higher temperature.

Transistor, diode, SCR are some electronic devices.

title: Physics Study Guide/Electronics


text:
User talk:24.223.158.245

Thanks for trying out Wikibooks - try the sandbox and Research to get started

title: User talk:24.223.158.245


text:
Talk:High School Mathematics Extensions/Logic/Problem Set/Solutions

That 203.88.166.38 is me, Tom Lam or lemontea(it keeps kicking me out while I'm editing)

Why is there no boarder with table?

Problem on the solution
On the questions about NAND, I've find the answer that's simplier,using only six NAND operators.

{[(x NAND x) NAND (y NAND y)] NAND w} NAND (z NAND z)

Solution: Let (x+y)w+z = a NAND b, where a and b can either be one of x,y,w,z or another NAND operator.

$$(x+y)w+z=(ab)'$$

$$(x+y)w+z=a'+b'$$

Therefore $$a=[(x+y)w]'$$ and $$b=z'$$, both need further NAND operators. Let a = c NAND d, and let b = e NAND f.

$$(x+y)w+z={(cd)'}^{'}+{(ef)'}^{'}$$

$$(x+y)w+z=cd+ef$$

Therefore d=w, e=f=z,c=x+y.Let c = g NAND h.

$$x+y=(gh)'$$

$$x+y=g'+h'$$

Now g=x' and h=y', we still need more NAND operators. Let g = i NAND j and let h = k NAND l.

$$(ij)'=x'$$ $$x=ij$$ $$(kl)'=y'$$ $$kl=y$$

Therefore i=j=x and k=l=y.

Now substitute all the variables back, you should get:

(x+y)w+z={[(x NAND x) NAND (y NAND y)] NAND w} NAND (z NAND z)

Thanks.

 * Hey, tops! Did you figure this out yourself? Really good. Xiaodai 09:08, 20 Nov 2004 (UTC)
 * Actually i didn't read the solutions. The one in there is a shocker. Xiaodai 09:14, 20 Nov 2004 (UTC)
 * Hi!Yes, I did figure this out myself, but I just want to ask: what do you mean by "shocker" and "i didn't read the solutions." in your last comment? I'm completely confused.Lemontea 19:25, 20 Nov 2004 (GMT+8)


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Buddhist Philosophy/Esoteric Buddhism

 * Mahayana Dictum - "Emptiness is form and form is emptiness" can be expressed as a formula:

 * $$\frac{\infin=1=0}{2}$$

 * Esoteric Buddhist Schools include: Tendai, Shingon, Tantric and are the antithesis of the ../Yinyana/ and other open systems. Often based on supernatural teachings incorporating traditional beliefs (and superstitions), they nonetheless integrate some depth psychology and healing methods.

Introduction
Esoteric Buddhism is generally classified under the Great Vehicle (Mahayana) Buddhism. There are two parts to it: the Exoteric and the Esoteric Buddhism. In order for us to understand Esoteric Buddhism, we need to explore the origins as well the constituent philosophy and historical context of how the respective schools were established.

Exoteric Buddhism is based on Madhyamika ('middle way') of Nagarjuna.

Esoteric Buddhism requires the study of Exoteric Buddhism as the foundation. Esoteric Buddhism is taught to practitioners as an 'advanced' dharma.

Doctrine
The doctrine of the Esoteric (or Tantric) Buddhism is based on Mahavairocana-sutra, and Kalacakraindriya-sutra. The following may best explain the doctrine:
 * Taking the six elements as essence
 * Five Wisdom Buddhas
 * Taking the four mandalas as appearance
 * Taking the three secrets as means
 * Cause, base, final means
 * Anger and fear

Reference
Lecture delivered by Master Sheng-yen on Esoteric and Exoteric Buddhism

Article by A. P. Sinnett Esoteric Buddhism

title: Buddhist Philosophy/Esoteric Buddhism


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Curl/Interviews

Interviews

Please feel free to add your own questions and answers!

=Interview with "The Fridge"=

Are you known as 'the Fridge' because you are a kewl programmer?
When last time I had a temperature I wasn't so kewl. I think Fridge is the transcription of the German word "Fritte" (like potato chips) which is my nickname in Germany.

Is Curl evolutionary or revolutionary?
This binary question is not so easily answered. Curl is of course evolutionary because there have been other programming languages before. It wouldn't be the MIT if they hadn't learnt from previous mistakes. On the other hand Curl comes with a revolutionary license policy. Don't ask for details the answer might take months.

What is your favourite piece of Curl programming? Hint: try and include curlchat
I would say the "Hello World" program, as it nicely shows how markup language is integrated in the object-oriented programming language. There are also some really good applications around, most of them are not available on the net but have a look a www.curlchat.info for example and you will know what I mean.

Can Curl be used for programming mobile phones or PDA's?
No, not yet. If the Asian market produces enough revenue there might be a possibility that Curl is ported to these devices.

Why is your baby son a worshipped deity?
I don't understand the question.

How does Curl fit in with the Semantic Web?
Oh, a technical question. Curl is great in collection information and preparing them in a sensible way. Yes, Curl programs can give meaning to a arbitrary sets of data retrieved from different sources.

What is your connection to alchemy and time travel?
Yesterday, I was working with Curl version 4.2 that was released in 1992. But unfortunately, I was already so rich (look at all these gold nuggets on my desk) that I couldn't to see the ingenuity of the release.

Why are you so keen on Curl?
Because. Do you really want a personal answer?

title: Curl/Interviews


text:
Talk:Portuguese/Contents/Personal Pronouns of Subject

Untitled
The form "Vós" (plural "you") is NOT outdated. it is used in the northern Portugal, among northern dialects speakers. Also it is NOT formal there.

Capitalization
It is probably a good idea to avoid capitalizing the pronouns, except when it is required (for example, at the start of a sentence). Chonak 17:58, 9 April 2006 (UTC)

he/she
Suggestion: In Portuguese the undetermined gender is masculine, without the use of ele/ela (he/she). This politically correct construction in English, and the lack of it in Portuguese, could be developed in this article. (Right now I don't have enough references to deal with this.)66.18.232.233 (discuss) 21:09, 11 May 2012 (UTC)


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Ruby Programming/GUI Toolkit Modules/Tk

Of Ruby GUI bindings, the Tk binding is the oldest; it is widely available and still more or less the default toolkit for GUI programming with Ruby. Nevertheless, currently there exists no comprehensive manual for Ruby/Tk; the Ruby book recommends inferring Ruby/Tk usage from the Perl/Tk documentation.

The current Ruby "PickAxe book" has a chapter on Ruby/Tk.

Documentation

 * There’s a pretty good tutorial www.tutorialspoint.com/ruby/ruby_tk_guide.htm.

 * There are some pleasantly looking tutorials at tkdocs.com (it’s not really Tk’s official site).

 * After having introducted yourself to the concepts of Tk you should also be able to read TclTk’s official reference (this is also available as man pages on Unix or a CHM file on Windows ).

You may also be able to comfortably read PerlTk’s documentation as the Ruby bindings are said to be modeled after Perl’s.

Look and Feel
The “look and feel” of your Tk application depends on the version of the Tk library your Ruby interpreter is linked against:

 * Tk 8.4 and below is notorious for its “ugly” look. The widgets have the outdated Motif look and feel, and, on Unix-based systems, bitmap fonts are used.

 * Tk 8.5 and above look more modern. It is shipped with the Tile theming engine, and widgets now look native to the hosting platform . On Unix-based systems outline fonts are now used.

Availability
If the Tk toolkit isn’t already installed on your system, you’ll have to install it. You may use your system’s “package manager” for this.

If you built Ruby before having installed the Tk dev package, it’s likely that it was built without Tk built in. For 1.9 versions you might be able to get away with installing it as a gem but your best bet is to install the tk dev package and reinstall Ruby so that it builds with the Tk bindings.

Windows
By default the “old” one click installer has the Tk binaries, however you’ll still need to install the Tk toolkit from ActiveState.

If you’re using the new “rubyinstaller” then for 1.8.6 this might help or for 1.9 this might help

There’s a precompiled gem which should work out-of-the-box: tk-win.

It includes sources and libraries directly from Hidetoshi NAGAI. It’s Ruby 1.9 only.

You could also try the ffi-tk gem, or download this for 1.9 mingw users.

The hope is that future versions of rubyinstaller will come with the binaries built in, then the above work-arounds won’t be necessary.

|

title: Ruby Programming/GUI Toolkit Modules/Tk


text:
Perl Programming/Simple examples 2

Hi-Lo: A simple game written in perl that asks you for a guess between 1 and 100 and tells you if you are too high or low.

title: Perl Programming/Simple examples 2


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Cookbook:Shepherd's Pie II

| Canadian recipes

Pâté Chinois (Chinese Pie), sometimes known as shepherd's pie, is a simple dish made from layered hamburger, creamed corn, and mashed potatoes.

Ingredients

 * 1 pound (450 g) lean ground hamburger meat
 * 3–4 cups mashed potatoes
 * 12 oz (341 ml or 1 can) creamed corn
 * Salt, pepper, and butter to taste
 * 1–2 cups shredded Cheddar or Mexican blend cheese (optional, amount depends on how much cheese you want)

Procedure

 * 1) Preheat the oven to 350°F (175°C)
 * 2) In a large skillet, brown the hamburger meat until it is no longer pink
 * 3) In a medium baking pan, evenly layer the meat on the bottom, then corn. Spread a layer of potatoes.
 * 4) If using, sprinkle cheese on top.
 * 5) Bake in the oven for about 30 minutes, or until the cheese is melted.

Notes, tips, and variations

 * Possible toppings include paprika, parsley, ketchup or green tomato chow-chow (ketchup vert).
 * Other variations include frying the meat with a diced onion, as well as using an equal combination of creamed corn and regular corn.
 * See also Shepherd's Pie and Pâté chinois.

Warnings

 * Always follow safe handling guidelines when using raw meat.

title: Cookbook:Shepherd's Pie II


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Voter's Guide

The Wikibooks Voter's Guide is a project designed to educate potential voters on how to vote, as well as the possible benefits and disadvantages of voting in particular ways. Though this is the English Wikibooks project and all Voter's Guides contained herein should be in English, there should be intense cooperation and interlinking to ensure that voters can access a Voter's Guide for their country and in their native language. To this end, the English project should have English language guides to elections in countries like the United States, Canada, Australia, South Africa, United Kingdom and Jamaica, guides should also be made available in English for any country, even non-Anglophone lands like China, Japan and France.

 * /Australia/
 * /Canada/
 * /New Zealand/
 * /United Kingdom/
 * /United States/

Each Voter's Guide should have several sections (using the US as an example):
 * Brief stuff to be given out at polling stations:
 * Voter's Guide/United States/Candidates/Presidential: Brief information, short enough to be given out at polling stations and read just before voting, on the platforms of the candidates for President of the United States
 * Voter's Guide/United States/Candidates/Congressional: Brief information, short enough to be given out at polling stations and read just before voting, on the platforms of the candidates for Senator or Representative, divided by state (e.g. Voter's Guide/United States/Congressional candidates/Alaska)
 * In-depth info, too long to be portable or easily distributable
 * Voter's Guide/United States/Elections/Congressional: More in depth information on the candidates and issues behind the election; information on how and why (and why not) strategic voting can be harmful or beneficial
 * Voter's Guide/United States/Democratic Party: Information on the platform and history of the Democratic Party (this is an example of one Party Guide)
 * Voter's Guide/United States/George W. Bush: Simple biographical information, followed by long list of positions taken, bills supported/opposed, promises made (with info on if kept) (this is an example of one Candidate Guide)

title: Voter's Guide