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Talk:Financial Derivatives

I'm starting to write this book because I have a decent grasp of the math behind financial derivatives but I'd like a better one. It has been my experience that teaching or writing about a subject gives a better comprehension. I will be drawing heavily on John C. Hull and wikipedia, along with other assorted resources.

I think it is a good idea to write this book. But why did you stop writing on it. A chapter about Credit Derivatives, Collateralized Debt Obligations, Credit Default Swaps and how to price Synthetic CDO would be nice.

Financial Math
I dont agree that your article displays a very advanced grasp of the mathematics behind financial derivatives. Relying too much on the textbook by Hull risks accusations of plagiarism. --Tedblack 18:20, 23 January 2007 (UTC)

title: Talk:Financial Derivatives


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Linguistics/Phonetics

Introduction
If you have ever heard a person learning English as a second language say, "I want to go to the bitch" (meaning "I want to go to the beach"), you might understand the importance of mastering phonetics when learning new languages.

As such an example illustrates, few people in our society give conscious thought to the sounds they produce and the subtle differences they possess. It is unfortunate, but hardly surprising, that few language-learning books use technical terminology to describe foreign sounds. Language learners often hear unhelpful advice such as "It is pronounced more crisply". As scientists, we cannot be satisfied with this state of affairs. If we can classify the sounds of language, we are one step closer to understanding the gestalt of human communication.

The study of the production and perception of speech sounds is a branch of linguistics called phonetics, studied by phoneticians. The study of how languages treat these sounds is called phonology, covered in the next chapter. While these two fields have considerable overlap, it should soon become clear that they differ in important ways.

Phonetics is the systematic study of the human ability to make and hear sounds which use the vocal organs of speech, especially for producing oral language. It is usually divided into the three branches of (1) articulatory, (2) acoustic and (3) auditory phonetics. It is also traditionally differentiated from (though overlaps with) the field of phonology, which is the formal study of the sound systems (phonologies) of languages, especially the universal properties displayed in ALL languages, such as the psycholinguistic aspects of phonological processing and acquisition.

One of the most important tools of phonetics and phonology is a special alphabet called the International Phonetic Alphabet or IPA, a standardized representation of the sounds used in human language. In this chapter, you will learn what sounds humans use in their languages, and how linguists represent those sounds in IPA. Reading and writing IPA will help you understand what's really happening when people speak.

Phonetic transcription and the IPA
It is often convenient to split up speech in a language into segments, which are defined as identifiable units in the flow of speech. In many ways this discretization of speech is somewhat fictional, in that both articulation and the acoustic signal of speech are almost entirely continuous. Additionally, attempts to classify segments by nature must ignore some level of detail, as no two segments produced at separate times are ever identical. Even so, segmentation remains a crucial tool in almost all aspects of linguistics.

In phonetics the most basic segments are called phones, which may be defined as units in speech which can be distinguished acoustically or articulatorily. This definition allows for different degrees of wideness. In many contexts phones may be thought of as acoustic or articulatory targets which may or may not be fully reached in actual speech. Another, more commonly used segment is the phoneme, which will be defined more precisely in the next chapter.

It is important to keep in mind that while the segment may (or may not) be a reality of phonology, it is in no way an actual physical part of realized speech in the vocal tract. Realized speech is highly co-articulated, displays movement and spreads aspects of sounds over entire syllables and words. It is convenient to think of speech as a succession of segments (which may or may not coincide closely with ideal segments) in order to capture it for discussion in written discourse, but actual phonetic analysis of speech confounds such a model. It should be pointed out, however, that if we wish to set down a representation of dynamic, complex speech into static writing, segmental constructs are very convenient fictions to indicate what we are trying to set down. Similarly, syllables and words are convenient structures which capture the prosodic structure of a language, and are often notated in written form, but are not physical realities.

The International Phonetic Alphabet (IPA) is a system of phonetic notation which provides a standardized system of transcribing phonetic segments up to a certain degree of detail. It may be represented visually using charts, which may be found in full in Appendix A. We will leave a more detailed description of the IPA to the end of this chapter, but for now just be aware that text in square brackets [] is phonetic transcription in IPA. We will reproduce simplified charts of different subsets of the IPA here as they are explained.

Variations of IPA such as the well established Americanist phonetic notation and a new, simplified international version called SaypU are available, but IPA is more comprehensive and so preferred for educational use, despite its complexity.

To understand the IPA's taxonomy of phones, it is important to consider articulatory, acoustic, and auditory phonetics.

Articulatory phonetics
Articulatory phonetics is concerned with how the sounds of language are physically produced by the vocal apparatus. The units articulatory phonetics deals with are known as gestures, which are abstract characterizations of articulatory events.

Speaking in terms of articulation, the sounds that we utter to make language can be split into two different types: consonants and vowels. For the purposes of articulatory phonetics, consonant sounds are typically characterized as sounds that have constricted or closed configurations of the vocal tract. Vowels, on the other hand, are characterized in articulatory terms as having relatively little constriction; that is, an open configuration of the vocal tract. Vowels carry much of the pitch of speech and can be held different durations, such as a half a beat, one beat, two beats, three beats, etc. of speech rhythm. Consonants, on the other hand, do not carry the prosodic pitch (especially if devoiced and not nasalized) and do not display the potential for the durations that vowels can have. Linguists may also speak of 'semi-vowels' or 'semi-consonants' (often used as synonymous terms). For example, a sound such as [w] phonetically seems more like a vowel (with relative lack of constriction or closure of the vocal tract) but, phonologically speaking, behaves as a consonant in that it always appears before a vowel sound at the beginning (onset) of a syllable.

Consonants
Phoneticians generally characterize consonants as being distinguished by settings of the independent variables place of articulation (POA) and manner of articulation (MOA). In layman's terminology, POA is "where" the consonant is produced, while MOA is "how" the consonant is produced.

The following are descriptions of the different POAs:
 * Bilabial segments are produced with the lips held together, for instance the [p] sound of the English pin, or the [b] sound in bin.
 * Labiodental segments are produced by holding the upper teeth to the lower lip, like in the [f] sound of English fin.
 * Dental consonants have the tongue making contact with the upper teeth (area 3 in the diagram). An example from English is the [θ] sound in the word thin.
 * Alveolar consonants have the tongue touching the area of the mouth known as the alveolar ridge (area 4 in the diagram). Examples include the [t] in tin and [s] in sin.
 * Postalveolar consonants are similar to alveolars but more retracted (in area 5 in the diagram), like the [ʃ] of shin.
 * Palatal consonants are articulated at the hard palate (the middle part of the roof of the mouth, area 7 in the diagram). In English the palatal [j] sound appears in the word young.
 * Velar consonants are articulated at the soft palate (the back part of the roof of the mouth, known also as the velum, area 8 in the diagram). English [k] is velar, like in the word kin.
 * Glottal consonants are articulated far back in the throat, at the glottis (area 11 in the diagram, effectively the vocal folds). English [h] may be regarded as glottal.
 * Doubly articulated consonants have two points of articulation, such as the English labio-velar [w] of wit.

Other POAs are also possible, but will be described in more detail later on.

MOA involves a number of different variables which may vary independently:
 * Voicing: Try pronouncing the hissing sound [s] of the English word sip. Elongate the sound until you can produce it continuously for five seconds. Then do the same for the [z] sound in zip. Hold your hand to your throat, observing the different in tactile sensation between the two. you should notice that [z] creates vibrations, while [s] does not. This rapid vibration is in fact caused by the vocal folds, and it is referred to as voicing. Many different sounds can contrast solely based on a voicing difference: English [b, p] in bin, pin, [d, t] in din, tin, et cetera.

 * Nasality: Some sounds are produced with airflow through the nasal cavity. These are known as nasals. Nasal consonants in English include the [n] of not, the [m] of mit, and the [ŋ] of sing. Nasals may also contrast for voicing in some languages, but this is rare — in most languages, nasals are voiced.

 * Obstruency: Consonants involving a total obstruction of airflow are known as stops or plosives. Examples include English [p, b, t, d, k, g]. Fricatives are consonants with a steady stricture causing friction, for example [f, v, s, z, ʃ, ʒ]. Affricates begin with a stop-like closure followed by frication, like the [tʃ, dʒ] of English chip, jeans.

 * Sonorancy: Non-obstruents are classed as sonorants. This includes the already-mentioned nasals. Another important type of sonorant found in English is the approximant, in which articulatory organs produce a narrowing of the vocal tract, but leave enough space for air to flow without much audible turbulence. Examples include English [w, j, l, ɹ].

Knowing this information is enough to construct a simplified IPA chart of the consonants of English. As is conventional, MOA is organized in rows, and POA columns. Voicing pairs occur in the same cells; the ones in bold are voiced while the rest are voiceless.

Vowels
Vowels are very different from consonants, but our method of decomposing sounds into sets of features works equally well. Vowels can essentially be viewed as being combinations of three variables:
 * Height: This measured how close your tongue is to the roof of your mouth. For example, try pronouncing [æ] (as in "cat") and [i] (as in "feet"). Your mouth should be much more open for the former than the latter. Thus [æ] is called either open or low, and [i] either closed or high.
 * Backness: This is what is sounds like. Try, for example, alternating between pronouncing the vowels [æ] (as in "cat") and [ɑ] (as in "cot"), and get a feel for the position of your tongue in your mouth. It should move forward for [æ] and back for [ɑ], which is why the former is called a front vowel and the latter a back vowel.
 * Rounding: Pronouncing the vowels [i] and [u], and look at your lips in a mirror. They should look puckered up for [u] and spread out for /i/. In general, this "puckering" is referred to in phonetics as rounding.

Back vowels tend to be rounded, and front vowels unrounded, for reasons which will be covered later in this chapter. However, this tendency is not universal. For instance, the vowel in the French word bœuf is what would result from the vowel of the English word bet being pronounced with rounding. Some East and Southeast Asian languages possess unrounded back vowels, which are difficult to describe without a sound sample.

The cardinal vowels are a set of idealized vowels used by phoneticians as a base of reference.

The IPA orders the vowels in a similar way to the consonants, separating the three main distinguishing variables into different dimensions. The vowel trapezoid may be thought of as a rough diagram of the mouth, with the left being the front, the right the back, and the vertical direction representing height in the mouth. Each vowel is positioned thusly based on height and backness. Rounding isn't indicated by location, but when pairs of vowels sharing the same height and backness occur next to each other, the left member is always unrounded, and the right a rounded vowel. Otherwise, just use the general heuristic that rounded vowels are usually back. The following is a simplified version of the IPA vowel chart:

Many of these vowels will be familiar from (General American) English. The following are rough examples: Note, however, that in phonetics we can describe any segment in arbitrarily fine detail. As such, when we say that, say, the vowel in "cat" is [æ], we are sacrificing precision.

Some of these vowels have no English equivalent, but may be familiar from foreign languages. [a] represents the sound in Spanish "hablo", the front rounded [œ] vowel is that in French "bœuf", [y] is that of German "hüten", and [ɯ] (perhaps the most exotic to most English speakers) is found as the first vowel of European Portuguese "pegar".

Acoustic phonetics
Acoustic phonetics deals with the physical medium of speech -- that is, how speech manipulates sound waves.

Sound is composed of waves of high- and low-pressure areas which propagate through air. The most basic way to view sound is as a wave function. This plots the pressure measured by the sound-recording device against time, corresponding closely to the physical nature of sound. Loudness may be found by looking at the amplitude of the sound at a given time.

However, this approach is fairly limited. Humans, in fact, don't process sound using this raw data. The ear analyzes sound by decomposing it into its constituent frequencies, a mathematical algorithm known as the Fourier transform.

As a sound is produced in the oral tract, the column of air in the tract serves as a harmonic oscillator, oscillating at numerous frequencies simultaneously. Some of the frequencies of oscillation are at higher amplitudes than others, a property called resonance. The resonant frequencies (frequencies with relatively high resonance) of the vocal tract are known in phonetics as formants. The formants in a speech sound are numbered by their frequency: f1 (pronounced eff-one) has the lowest frequency, followed by f2, f3, etc. The analysis of formants turns out to be key to acoustic phonetics, as any change in the shape of the vocal cavity changes which resonances are dominant.

There are two basic ways to analyze the formants of a speech signal. Firstly, at any given time the sound contains a mixture of different frequencies of sound. The relative amplitudes (strengths) of different frequencies at a particular time may be shown as a frequency spectrum. As you can see on the right, frequency is plotted against amplitude, and formants show up as peaks.

Another way to view formants is by using a spectrogram. This plots time against frequency, with amplitude represented by darkness. Formants show up as dark bands, and their movement may be tracked through time.

Given the development of modern technology, acoustic analysis is now accessible to anyone with a computer and a microphone.

Auditory phonetics
Auditory phonetics is a branch of phonetics concerned with the hearing of speech sounds and with speech perception.

As a learner
Children learn the sounds made in their native language within their first year, and after this it becomes difficult to produce sounds foreign to their native languages. Even familiar segments are produced without reflection on the manner of their production. As such, it is highly recommended that you practice pronouncing isolated segments, and listen repeatedly to examples of those which seem exotic to you. Soon, you will be noticing yourself becoming more observant as to the phones you hear in your everyday life, and will be less puzzled by unfamiliar segments in other languages.

Exercise 1: English Places of Articulation
The following English words were tagged with the place of articulation of their first segment, but the tags have been scrambled. Match each word with the correct POA:

Exercise 2: Brezhoneg
The following text in the Breton language has been translated into English:

Ar brezhoneg a zo ur yezh predenek eus skourr ar yezhoù keltiek komzet en darn vrasañ eus Enez Vreizh abaoe an Henamzer betek an aloubadegoù Saoz. Tost eo tre d'ar c'herneveureg (Cornwall:Kernow) ha d'ar c'hembraeg (Wales:Cymru) ha nebeutoc'h d'ar yezhoù keltiek all a zo c'hoazh bev : Skoseg, Gouezeleg ha Manaveg (Scotland, Ireland, Isle of Man) (ar skourr gouezelek).

Breton is a Brythonic language belonging to the branch of Celtic spoken over most of Britain from prehistoric times until the Saxon invasions. It is closely related to Cornish (Cornwall:Kernow) and Welsh (Wales:Cymru) and more distantly to the other surviving Celtic languages, Scots, Irish and Manx Gaelic (Scotland, Ireland, Isle of Man) (The Goidelic group).

You have been commissioned to create a phonetic transcription of this text using the following recording of a native speaker:

Write the transcription, being as accurate as you can. (Hint: The Breton rhotic is similar to that of French.)

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

title: Linguistics/Phonetics


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User:Bedawyn

Who I Am

Projects I'm following:

Alchemy - Last pass 9-30-04

Introduction to Paleoanthropology - Ongoing (through Ch. 4)

title: User:Bedawyn


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Cryptography/Public Key Overview

We briefly mentioned ../Asymmetric Ciphers/ earlier in this book. In this and following chapters we will describe how they work in much more detail.

The discovery of public key cryptography revolutionized the practice of cryptography in the 1970s. In public key cryptography, the key used to encrypt a message is not the same as the key used to decrypt it. This requires an asymmetric key algorithm.

(All previous cryptographic algorithms and cryptosystems, now retroactively categorized as "symmetric key cryptography" or "shared key cryptography", always use the same key to encrypt a message and later to decrypt that message).

Public key cryptography is cryptography where the key exchange process between person A and person B must not be kept secret. Private keys actually are never exchanged. In fact Person A sends information (possibly about a session key) to Person B so that it is only interpretable to Person B. An intruder cannot discover the meaning of the exchange because Person B has a piece of information that the intruder does not. Person A didn't access Person B's secret information (private key) either he only indirectly accessed it via a "public" key. The public key is formed from the private key by using a One-Way Function.

The concepts behind public key cryptography are best expressed by a simple puzzle.

''Alice wants to send a trinket to Bob without an intruder stealing it. Each person has a lock and a key.'' A Non-Public Key Solution
 * 1) Alice puts her key in the box and sends to Bob.
 * 2) Bob copies the key and sends it back.
 * 3) Alice sends the trinket in a locked box.
 * 4) Bob opens the box with the copied key.

This solution, although the most intuitive, suffers from a major problem. The intruder could monitor the boxes and copy the key as it sent. If an intruder has Alice's key the trinket or anything else will be stolen in transit. To some the puzzle seems impossible, but those who understand public key cryptography solve it easily. Public Key Solution The puzzle's trick is double locking the box.
 * 1) Alice puts the trinket in a box, locks it and sends it to Bob.
 * 2) Bob locks the box again with his lock and sends the box back.
 * 3) Alice removes her lock and sends it to Bob.
 * 4) Bob removes the final lock and takes the trinket.

This back-and-forth "double lock" process is used in many asymmetric key algorithms, such as ElGamal encryption and Diffie–Hellman key exchange, but not all of them.

This is the double lock principle, but it is not Public Cryptography as both keys are secret. In public cryptography one key is public, the other is secret. Nobody knowing the public key is able to decipher a message encrypted with a public key. Only the secret key is able to decipher a message encrypted with a public key.

A real-world analogy to public keys would be the padlock. The padlock can be easily closed, but it is much harder to do the reverse, namely opening. It is not impossible, but it requires much more effort to open it than to close it, assuming you don't have the (private) key. Alice could send Bob an open padlock by mail (the equivalent to the public key). Bob then puts a message for Alice into a box and locks the box with the padlock. Now, Bob sends the locked box back to Alice and Alice opens it with her private key.

Note that this approach is susceptible to man-in-the-middle attacks. If Charles intercepts the mail with Alice's padlock and replaces it with his own padlock, Bob will lock the box with the wrong padlock and Charles will be able to intercept the answer. Charles could then even lock the box again with Alice's padlock and forward the box to Alice. That way, she will never notice that the message got intercepted. This illustrates that it is very important to obtain public keys (the padlocks) from a trusted source. That's what certificates are for. They come along with the public keys and basically say something like 'I, Microsoft, hereby confirm that this padlock belongs to Alice', and are signed using secure digital signatures.

So someone (Bob) is able to send securely an encrypted data to Alice, if Alice had made her key public.

Bob is able to prove that he owns a secret key only by providing:

 * a plain text
 * the same text encrypted with the secret key
 * the public key corresponding to the secret key.

Something similar to the double lock principle is Merkle's puzzle, which is the ancestor of the Diffie–Hellman key exchange, which is itself a close cousin to RSA public key system.

title: Cryptography/Public Key Overview


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File:Letter frequency.PNG

Summary
Letter frequency for English language- i made it in excel

title: File:Letter frequency.PNG


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User:Eibwen

Eibwen, make a page! --Waxmop 02:22, 2 Oct 2004 (UTC)

title: User:Eibwen


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Introduction to Paleoanthropology/Hominids Acheulean

African Homo erectus: Homo ergaster
H. ergaster existed between 1.8 million and 1.3 million years ago.

Like H. habilis, the face shows: Early H. ergaster specimens average about 900 cc, while late ones have an average of about 1100 cc. The skeleton is more robust than those of modern humans, implying greater strength.
 * protruding jaws with large molars;
 * no chin;
 * thick brow ridges;
 * long low skull, with a brain size varying between 750 and 1225 cc.

Body proportions vary:
 * Ex. Turkana Boy is tall and slender, like modern humans from the same area, while the few limb bones found of Peking Man indicate a shorter, sturdier build.

Study of the Turkana Boy skeleton indicates that H. ergaster may have been more efficient at walking than modern humans, whose skeletons have had to adapt to allow for the birth of larger-brained infants.

Homo habilis and all the australopithecines are found only in Africa, but H. erectus/ergaster was wide-ranging, and has been found in Africa, Asia, and Europe.

Asian Homo erectus
Specimens of H. erectus from Eastern Asia differ morphologically from African specimens:
 * features are more exaggerated;
 * skull is thicker, brow ridges are more pronounced, sides of skull slope more steeply, the sagittal crest is more exaggerated;
 * Asian forms do not show the increase in cranial capacity.

As a consequence of these features, they are less like humans than the African forms of H. erectus.

Paleoanthropologists who study extinct populations are forced to decide whether there was one species or two based on morphological traits alone. They must ask whether eastern and western forms are as different from each other as typical species.

If systematics finally agree that eastern and western populations of H. erectus are distinct species, then the eastern Asian form will keep the name H. erectus. The western forms have been given a new name: Homo ergaster (means "work man") and was first applied to a very old specimen from East Turkana in East Africa.

Homo georgicus
Specimens recovered recently exhibit characteristic H. erectus features: sagittal crest, marked constriction of the skull behind the eyes. But they are also extremely different in several ways, resembling H. habilis:
 * small brain size (600 cc);
 * prominent browridge;
 * projection of the face;
 * rounded contour of the rear of skull;
 * huge canine teeth.

Some researchers propose that these fossils might represent a new species of Homo: H. georgicus.

Homo antecessor
Named in 1997 from fossils (juvenile specimen) found in Atapuerca (Spain). Dated to at least 780,000 years ago, it makes these fossils the oldest confirmed European hominids.

Mid-facial area of antecessor seems very modern, but other parts of skull (e.g., teeth, forehead and browridges) are much more primitive. Fossils assigned to new species on grounds that they exhibit unknown combination of traits: they are less derived in the Neanderthal direction than later mid-Quaternary European specimens assigned to Homo heidelbergensis.

Homo heidelbergensis
Archaic forms of Homo sapiens first appeared in Europe about 500,000 years ago (until about 200,000 years ago) and are called Homo heidelbergensis.

Found in various places in Europe, Africa and maybe Asia.

This species covers a diverse group of skulls which have features of both Homo erectus and modern humans. Fossil features:
 * brain size is larger than erectus and smaller than most modern humans: averaging about 1200 cc;
 * skull is more rounded than in erectus;
 * still large brow ridges and receding foreheads;
 * skeleton and teeth are usually less robust than erectus, but more robust than modern humans;
 * mandible is human-like, but massive and chinless; shows expansion of molar cavities and very long cheek tooth row, which implies a long, forwardly projecting face.

Fossils could represent a population near the common ancestry of Neanderthals and modern humans.

Footprints of H. heidelbergensis (earliest human footprints) have been found in Italy in 2003.

Phylogenic relationships
For almost three decades, paleoanthropologists have often divided the genus Homo among three successive species:
 * Homo habilis, now dated between roughly 2.5 Myrs and 1.7 Myrs ago;
 * Homo erectus, now placed between roughly 1.7 Myrs and 500,000 years ago;
 * Homo sapiens, after 500,000 years ago.

In this view, each species was distinguished from its predecessor primarily by larger brain size and by details of cranio-facial morphology:
 * Ex. Change in braincase shape from more rounded in H. habilis to more angular in H. erectus to more rounded again in H. sapiens.

The accumulating evidence of fossils has increasingly undermined a scenario based on three successive species or evolutionary stages. It now strongly favors a scheme that more explicitly recognizes the importance of branching in the evolution of Homo.

This new scheme continues to accept H. habilis as the ancestor for all later Homo. Its descendants at 1.8-1.7 million mears ago may still be called H. erectus, but H. ergaster is now more widely accepted. By 600,000-500,000 years ago, H. ergaster had produced several lines leading to H. neanderthalensis in Europe and H. sapiens in Africa. About 600,000 years ago, both of these species shared a common ancestor to which the name H. heidelbergensis could be applied.

"Out-of-Africa 1" model
Homo erectus in Asia would be as old as Homo ergaster in Africa. Do the new dates from Dmanisi and Java falsify the hypothesis of an African origin for Homo erectus? Not necessarily.

If the species evolved just slightly earlier than the oldest African fossils (2.0-1.9 million years ago) and then immediately began its geographic spread, it could have reached Europe and Asia fairly quickly.

But the "Out-of-Africa 1" migration is more complex. Conventional paleoanthropological wisdom holds that the first human to leave Africa were tall, large-brained hominids (Homo ergaster/erectus). New fossils discovered in Georgia (Dmanisi) are forcing scholars to rethink that scenario completely. These Georgian hominids are far smaller and more primitive in both anatomy and technology than expected, leaving experts wondering not only why early humans first ventured out of Africa, but also how.

Summary
Homo ergaster was the first hominid species whose anatomy fully justify the label human:
 * Unlike australopithecines and Homo habilis, in which body form and proportions retained apelike features suggesting a continued reliance on trees for food or refuge, H. ergaster achieved essentially modern forms and proportions;
 * Members also differed from australopithecines and H. habilis in their increased, essentially modern stature and in their reduced degree of sexual dimorphism.


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Talk:Introduction to Paleoanthropology/Definition

Because of this, the concept of an ecological niche does not apply to humans anymore.

I think this is debatable, and should probably be removed. We can operate outside our ecological niche -- on submarines in the ocean or scuba diving with breathing tanks, with special cold-weather equipment on the highest mountains or even on spacecraft beyond the atmosphere -- but we still have an ecological niche.

Also, I think it might be wise in this first chapter to either avoid using the hominoid/hominid/hominin terms completely or else take the time to define them right off. It can be confusing enough to remember which is which even when you know what they are, much less if you're new to the field and don't realize they're really separate terms and not just variant spellings of the same term.--Bedawyn 02:45, 2 Oct 2004 (UTC)


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User:Porton~enwikibooks

Victor Porton from Russia

 * Homepage

 * Wiki projects (not full list):
 * 21 Century Math Method - a new math method replacing axiomatic method with a new simple and powerful formal system and the assocciated methodology.
 * Binding properties (programming)

Please donate for me to have the possibility to work more on free projects such as WikiResearch, free software, and mathematics, rather than uselessly spend time on business.

title: User:Porton~enwikibooks


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Introduction to Paleoanthropology/Acheulean Technology

Homo ergaster/erectus, the author of the Acheulean industry, enjoyed impressive longevity as a species and great geographic spread. We will review several cultural innovations and behavioral changes that might have contributed to the success of H. ergaster/erectus:
 * stone-knapping advances that resulted in Acheulean bifacial tools;
 * the beginnings of shelter construction;
 * the control and use of fire;
 * increased dependence on hunting.

The Acheulean industrial complex
(1.7 million - 200,000 years ago)

Stone tools
By the time Homo ergaster/erectus appeared, Oldowan choppers and flake tools had been in use for 800,000 years. For another 100,000 to 400,000 years, Oldowan tools continued to be the top-of-the-line implements for early Homo ergaster/erectus. Between 1.7 and 1.4 million years ago, Africa witnessed a significant advance in stone tool technology: the development of the Acheulean industry. The Acheulean tool kit included:
 * picks;
 * cleavers;
 * an assortment of Oldowan-type choppers and flakes, suggesting that the more primitive implements continued to serve important functions;
 * mainly characterized by bifacially flaked tools, called bifaces.

A biface reveals a cutting edge that has been flaked carefully on both sides to make it straighter and sharper than the primitive Oldowan chopper. The purpose of the two-sided, or bifacial, method was to change the shape of the core from essentially round to flattish, for only with a flat stone can one get a decent cutting edge.

One technological improvement that permitted the more controlled working required to shape an Acheulean handax was the gradual implementation, during the Acheulean period, of different kinds of hammers. In earlier times, the toolmaker knocked flakes from the core with another piece of stone. The hard shock of rock on rock tended to leave deep, irregular scars and wavy cutting edges.

But a wood or bone hammer, being softer, gave its user much greater control over flaking. Such implements left shallower, cleaner scars and produced sharper and straighter cutting edges.
 * With the Acheulean Industry, the use of stone (hard hammer) was pretty much restricted to the preliminary rough shaping of a handax, and all the fine work around the edges was done with wood and bone.

Acheulean handaxes and cleavers are generally interpreted as being implements for processing animal carcasses. Even though cleavers could have been used to chop and shape wood, their wear patterns are more suggestive of use on soft material, such as hides and meat. Acheulean tools represent an adaptation for habitual and systematic butchery, and especially the dismembering of large animal carcasses, as Homo ergaster/erectus experienced a strong dietary shift toward more meat consumption.

Acheulean tools originated in Africa between 1.7 and 1.4 million years ago. They were then produced continuously throughout Homo ergaster/erectus'  long African residency and beyond, finally disappearing about 200,000 years ago.

Generally, Acheulean tools from sites clearly older than 400,000 to 500,000 years ago are attributed to Homo ergaster/erectus, even in the absence of confirming fossils. At several important Late Acheulean sites, however, the toolmakers' species identity remains ambiguous because the sites lack hominid fossils and they date to a period when Homo erectus and archaic Homo sapiens (e.g., Homo heidelbergensis) overlapped in time.

Other raw materials
Stone artifacts dominate the Paleolithic record because of their durability, but early people surely used other raw materials, including bone and more perishable substances like wood, reeds, and skin.

A few sites, mainly European, have produced wooden artifacts, which date usually between roughly 600,000 and 300,000 years ago:
 * Ex. At the site of Schöningen, Germany, several wooden throwing spears, over 2 m long. They arguably present the oldest, most compelling case for early human hunting.

Diffusion of Technology
Wide variability in stone tools present with H. erectus. In Eastern Asia, H. erectus specimens are associated not with Acheulean tools, but instead with Oldowan tools, which were retained until 200,000 to 300,000 years ago.

This pattern was first pointed out by Hallam Movius in 1948. The line dividing the Old World into Acheulean and non-Acheulean regions became known as the Movius line. Handax cultures flourished to the west and south of the line, but in the east, only choppers and flake tools were found.

Why were there no Acheulean handax cultures in the Eastern provinces of Asia?
 * history of research;
 * other explanations:
 * quality of raw materials (fine-grained rocks rare)
 * different functional requirements (related to environment and food procurement)
 * "bamboo culture": bamboo tools used in place of stone implements to perform tasks;
 * Early dates in Java and Dmanisi explain situation
 * Acheulean developed in Africa from the preceding Oldowan Tradition only after 1.8 Myrs ago, but if people moved into eastern Asia at 1.8 million years ago or before, they would have arrived without Acheulean tools.

In sum, while the Acheulean tradition, with its handaxes and cleavers, was an important lithic advance by Homo ergaster over older technologies, it constituted only one of several adaptive patterns used by the species. Clever and behaviorally flexible, H. ergaster was capable of adjusting its material culture to local resources and functional requirements.

Subsistence patterns and diet
Early discoveries of Homo ergaster/erectus fossils in association with stone tools and animal bones lent themselves to the interpretation of hunting and gathering way of life. Nevertheless this interpretation is not accepted by all scholars and various models have been offered to make sense of the evidence.

First Scenario: Scavenging
Recently, several of the original studies describing Homo ergaster/erectus as a hunter-gatherer have come under intense criticism. Re-examination of the material at some of the sites convinced some scholars (L. Binford) that faunal assemblages were primarily the result of animal activity rather than hunting and gathering.

Animal bones showed cut marks from stone tools that overlay gnaw marks by carnivores, suggesting that Homo ergaster/erectus was not above scavenging parts of a carnivore kill.

According to these scholars, at most sites, the evidence for scavenging by hominids is much more convincing than is that for actual hunting.

Which scenario to choose?
The key point here is not that Homo ergaster/erectus were the first hominid hunters, but that they depended on meat for a much larger portion of their diet than had any previous hominid species.

Occasional hunting is seen among nonhuman primates and cannot be denied to australopithecines (see A. garhi). But apparently for Homo ergaster/erectus hunting took an unprecedented importance, and in doing so it must have played a major role in shaping both material culture and society.

Shelter and fire
For years, scientists have searched for evidence that Homo ergaster/erectus had gained additional control over its environment through the construction of shelters, and the control and use of fire. The evidence is sparse and difficult to interpret.

Shelter
Seemingly patterned arrangements or concentrations of large rocks at sites in Europe and Africa may mark the foundations of huts or windbreaks, but in each case the responsible agent could equally well be stream flow, or any other natural process.

Therefore there appears to be no convincing evidence that Homo ergaster/erectus regularly constructed huts, windbreaks, or any other sort of shelter during the bulk of its long period of existence. Shelter construction apparently developed late in the species' life span, if at all, and therefore cannot be used as an explanation of H. ergaster's capacity for geographic expansion.

Fire
Proving the evidence of fire by Homo ergaster/erectus is almost equally problematic. Some researchers have suggested that the oldest evidence for fire use comes from some Kenyan sites dated about 1.4 to 1.6 million years ago. Other scholars are not sure. The problem is that the baked earth found at these sites could have been produced as easily by natural fires as by fires started - or at least controlled - by H. ergaster/erectus.

Better evidence of fire use comes from sites that date near the end of Homo erectus'  existence as a species. Unfortunately, the identity of the responsible hominids (either Homo erectus or archaic Homo sapiens) is unclear.

The evidence at present suggests that fire was not a key to either the geographic spread or the longevity of these early humans.

Out-of-Africa 1: Behavioral aspects
Researchers proposed originally that it was not until the advent of handaxes and other symmetrically shaped, standardized stone tools that H. erectus could penetrate the northern latitudes. Exactly what, if anything, these implements could accomplish that the simple Oldowan flakes, choppers and scrapers that preceded them could not is unknown, although perhaps they conferred a better means of butchering.

But the Dmanisi finds of primitive hominids and Oldowan-like industries raise once again the question of what prompted our ancestors to leave their natal land.

Yet, there is one major problem with scenarios involving departure dates earlier than about 1.7-1.4 million years ago, and that is simply that they involve geographic spread before the cultural developments (Acheulean industry, meat eating, fire, shelter) that are supposed to have made it possible.

A shift toward meat eating might explain how humans managed to survive outside of Africa, but what prompted them to push into new territories remains unknown at this time.

Perhaps they were following herds of animal north. Or maybe it was as simple and familiar as a need to know what lay beyond that hill or river or tall savanna grass. Also an early migration could explain technological differences between western and eastern Homo erectus populations.

The link between butchering tools and moves into northern latitudes is the skinning and preparation of hides and furs, for reworking 1. into portable shelters, and 2. into clothing. more skilful skinning meant that skins would be better preserved, while fire would lead to meat preservation (smoking) by the simple need to hang cuts of butchered meat high up out of reach of any scavenging animals within smoke filled caves or other dwellings. Having smoked meat then allowed deeper incursions into otherwise hostile terrain, or a long-term food supply available in harsh winters. With readily available and storable energy resources, and protective clothing, they could push out into harsh northern latitudes with comparative ease.

Summary
Overall, the evidence suggests that Homo ergaster was the first hominid species to resemble historic hunter-gatherers not only in a fully terrestrial lifestyle, but also in a social organization that featured economic cooperation between males and females and perhaps between semi-permanent male-female units.


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User talk:Bedawyn

Paleoanthropology
By all mean, please add to, copyedit and comment on this project. I'm converting many pages of notes into book-format and it does need some major collaboration-type work. - Davodd 02:53, 2 Oct 2004 (UTC)
 * Thanks for your valuable input (and copyediting). I agree with your notes on pulling out some of the chapters. I am re-organizing the book now, and think I will have them as suggested reading. As for the POV stuff, I think the issues need to be raised, but the language should be toned down with "some think" or "an argument can be made that..."-type stuff. Sure, they are weasle words, but I think it would be worse than to just leave the issues out altogether. I still have a couple more chapters to do. Unfortunately they are still in outline form from my laptop's notes. I probably will just put those notes up to finish the book in rough form - then work on fleshing them out later. Davodd 06:08, 3 Oct 2004 (UTC)

title: User talk:Bedawyn


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Cookbook:Garlic Parmesan Pasta

| Pasta Recipes

Ingredients

 * 120 ml (½ cup) butter
 * 2 tsp crushed dried basil
 * 2 tsp lemon juice
 * 1 ¼ tsp garlic powder
 * ¾ tsp seasoned salt
 * 220 g (8 oz) fettuccine or angel hair pasta, cooked and drained
 * 360 ml (1 ½ cups) broccoli florets, cooked tender-crisp
 * 3 Tbsp walnuts, chopped
 * Fresh, grated Parmesan cheese

Procedure

 * 1) Melt the butter in a large skillet. Add the basil, lemon juice, garlic powder and seasoned salt, blending well.
 * 2) Add the fettuccine, broccoli, and walnuts. Blend well and toss to coat the fettuccine.
 * 3) After tossing, add fresh grated Parmesan cheese to top off the dish.

Notes, tips, and variations

 * Cooked chicken breast or cooked shrimp may be added along with the pasta if desired.

title: Cookbook:Garlic Parmesan Pasta


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Talk:Introduction to Paleoanthropology/Dating Techniques

Was the all-caps for the 1.4 and 1.5 subheaders intentional? I wasn't sure if it was supposed to mark a difference in section types. Also, are these sections supposed to be contrasting, that is, saying paleoanthropology uses the 1.5 techniques but not the 1.4 techniques (from a different subdiscipline)?--Bedawyn


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Cookbook talk:Garlic Parmesan Pasta

This recipe was copied from Wikipedia on 10/1/04. Following is the history of this page. liblamb 03:24, 2 Oct 2004 (UTC)

 * (cur) (last) 18:42, 23 Sep 2004 Poccil
 * (cur) (last) 18:39, 23 Sep 2004 Poccil
 * (cur) (last) 10:56, 18 Sep 2004 Anthony DiPierro
 * (cur) (last) 12:10, 12 Sep 2004 Guanaco m (Reverted edits by Guanabot to last version by Big Bob the Finder)
 * (cur) (last) 04:51, 12 Sep 2004 Guanabot (Guanaco - robot)
 * (cur) (last) 21:24, 1 Aug 2003 Big Bob the Finder m (Update of "ancient" entries)
 * (cur) (last) 10:51, 25 Feb 2002 Conversion script m (Automated conversion)

title: Cookbook talk:Garlic Parmesan Pasta


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Introduction to Paleoanthropology/Modern Humans/Population Variation

One of the notable characteristics of the human species today is its great variability. Human diversity has long fascinated people, but unfortunately it also has led to discrimination. In this chapter we will attempt to address the following questions:
 * What are the causes of physical variability in modern animals?
 * Is the concept of race useful for studying human physical variation?
 * Are there differences in intelligence from one population to another?

Variation and evolution
Human genetic variation generally is distributed in such a continuous range, with varying clusters of frequency.
 * Ex. Our hair is curly or straight, our skin is lightly to heavily pigmented, and in height we range from short to tall.

The significance we give our variations, the way we perceive them (in fact, whether or not we perceive them at all) is determined by our culture.

Many behavioral traits are learned or acquired by living in a society; other characteristics, such as blue eyes, are passed on physically by heredity. Environment affects both.

The physical characteristics of both populations and individuals are a product of the interaction between genes and environments.
 * Ex. One's genes predispose one to a particular skin color, but the skin color one actually has is strongly affected by environmental factors such as the amount of solar radiation.

For most characteristics, there are within the gene pool of Homo sapiens variant forms of genes, known as alleles.
 * In the color of an eye, the shape of a hand, the texture of skin, many variations can occur.

This kind of variability, found in many animal species, signifies a rich potential for new combinations of characteristics in future generations. A species faced with changing environmental conditions has within its gene pool the possibility of producing individuals with traits appropriate to its altered life. Many may not achieve reproductive success, but those whose physical characteristics enable them to do well in the new environment will usually reproduce, so that their genes will become more common in subsequent generations. Thus, humankind has been able to occupy a variety of environments.

A major expansion into new environments was under way by the time Homo erectus appeared on the scene. Populations of this species were living in Africa, Southeast Asia, Europe and China. The differentiation of animal life is the result of selective pressures that, through the Pleistocene, differed from one region to another. Coupled with differing selective pressures were geographical features that restricted or prevented gene flow between populations of different faunal regions.
 * Ex. The conditions of life were quite different in China, which lies in the temperate zone, than they were in tropical Southeast Asia.

Genetic variants will be expressed in different frequencies in these geographically dispersed populations.
 * Ex. In the Old World, populations of Homo sapiens living in the tropics have a higher frequency of genes for dark skin than do those living in more northerly regions.

In blood type, H. sapiens shows four distinct groups (A, B, O or AB):
 * The frequency of the O allele is highest in Native Americans, especially among some populations native to South America;
 * The highest frequencies of the allele for Type A tend to be found among certain European populations;
 * The highest frequencies of the B allele are found in some Asian populations.

The Meaning of Race
Early anthropologists tried to explore the nature of human species by systematically classifying H. sapiens into subspecies or races, based on geographic location and physical features such as skin color, body size, head shape and hair texture. Such classifications were continually challenged by the presence of individuals who did not fit the categories.

The fact is, generalized references to human types such as "Asiatic" or "Mongoloid", "European" or "Caucasoid", and "African" or "Negroid" were at best mere statistical abstractions about populations in which certain physical features appeared in higher frequencies than in other populations.
 * No example of "pure" racial types could be found.

These categories turned out to be neither definitive nor particularly helpful. The visible traits were found to occur not in abrupt shifts from population to population, but in a continuum that changed gradually. Also one trait might change gradually over a north-south gradient, while another might show a similar change from east to west.
 * Human skin color becomes progressively darker as one moves from northern Europe to central Africa, while blood type B becomes progressively more common as one moves from western to eastern Europe.

Race as a biological concept
To understand why the racial approach to human variation has been so unproductive, we must first understand the race concept in strictly biological terms.

In biology, a race is defined as a population of a species that differs in the frequency of different variants of some gene or genes from other populations of the same species. Three important things to note about this definition:
 * it is arbitrary. There is no agreement on how many genetic differences it takes to make a race. For some, different frequencies in the variants of one gene are sufficient; for others, differences in frequencies involving several genes were necessary. The number of genes and precisely which ones are the more important for defining races are still open to debate;
 * it does not mean that any race has exclusive possession of any particular variant of any gene or genes. In human terms, the frequency of the allele for blood group O may be high in one population and low in another, but it is present in both. Races are genetically "open", meaning that gene flow takes place between them. Thus one can easily see the fallacy of any attempt to identify "pure" races: if gene flow cannot take place between two populations, either directly or indirectly through intermediate populations, then they are not races, but are separate species;
 * individuals of one race will not necessarily be distinguishable from those of another. In fact, the differences between individuals within a population are generally greater than the differences between populations.

The concept of human races
As a device for understanding physical variation in humans, the biological race concept has serious drawbacks:
 * the category is arbitrary, which makes agreement on any given classification difficult, if not impossible. For example, if one researcher emphasizes skin color, while another emphasizes blood group differences, they will not classify people in the same way. What has happened is that human populations have grown in the course of human evolution, and with this growth have come increased opportunities for contact and gene flow between populations. Since the advent of food production, the process has accelerated as higher birth rates and periodic food shortages have prompted the movement of farmers from their homelands to other places;
 * things are complicated even more because humans are so complicated genetically;
 * "race" exists as a cultural, as well as a biological, category. In various ways, cultures define religious, linguistic and ethnic groups as races, thereby confusing linguistic and cultural traits with physical traits;
 * to make the matter even worse, this confusion of social with biological factors is frequently combined with attitudes (racism) that are then taken as excuses to exclude whole categories of people from certain roles or positions in society. In the United States, for example, the idea of race originated in the 18th century to refer to the diverse peoples - European settlers, conquered Indians, and Africans imported as slaves - that were brought together in colonial North America. This racial worldview assigned some groups to perpetual low status on the basis of their supposedly biological inferiority, while access to privilege, power and wealth was reserved for favored groups of European descent.

There has been a lot of debate not just about how many human races there may be, but about what "race" is and is not. Often forgotten is the fact that a race, even if it can be defined biologically, is the result of the operation of evolutionary process. Because it is these processes rather than racial categories themselves in which we are really interested, most anthropologists have abandoned the race concept as being of no particular utility. Instead, they prefer to study the distribution and significance of specific, genetically based characteristics, or else the characteristics of small breeding populations that are, after all, the smallest units in which evolutionary change occurs.

Physical variables
Not only have attempts to classify people into races proven counterproductive, it has also become apparent that the amount of genetic variation in humans is relatively low, compared to that of other primate species.

Nonetheless, human biological variation is a fact of life, and physical anthropologists have learned a great deal about it. Much of it is related to climatic adaptation. A correlation has been noted between body build and climate:
 * Generally, people native to regions with cold climates tend to have greater body bulk (not to be equated with fat) relative to their extremities (arms and legs) than do people native to regions with hot climates, who tend to be long and slender. Interestingly, these differences show up as early as the time of Homo erectus.

Certain body builds are better suited to particular living conditions than others.
 * People with larger body bulk and shorter extremities may suffer more from summer heat than someone whose extremities are long and whose body is slender. But they will conserve needed body heat under cold conditions. The reason is that a bulky body tends to conserve more heat than a less bulky one, since it has less surface relative to volume;
 * People living in hot, open country, by contrast, benefit from a body build that can get rid of excess heat quickly so as to keep from overheating; for this, long extremities and a slender body, which increase surface area relative to volume, are advantageous.

Anthropologists have also studied such body features as nose, eye shape, hair textures and skin color in relation to climate.
 * Ex. Subject to tremendous variation, skin color is a 	function of four factors: transparency or thickness of the skin, distribution of blood vessels, and amount of carotene and melanin in a given area of skin. Exposure to sunlight increases the amount of melanin, darkening the skin. Natural selection has favored heavily pigmented skin as protection against the strong solar radiation of equatorial latitudes. In northern latitudes, natural selection has favored relatively depigmented skins, which can utilize relatively weak solar radiation in the production of Vitamin D. Selective mating, as well as geographical location, plays a part in skin color distribution.

Continuing human biological evolution
In the course of their evolution, humans in all parts of the world came to rely on cultural rather than biological adaptation for their survival. Nevertheless, as they spread beyond their tropical homeland into other parts of the world, they did develop considerable physical variation from one population to another.

The forces responsible for this include:
 * genetic drift, especially at the margins of their range where small populations were isolated for varying amounts of time;
 * biological adaptation to differing climates.

Although much of this physical variation can still be seen in human populations today, the increasing effectiveness of cultural adaptation has often reduced its importance. Cultural practices today are affecting the human organism in important, often surprising, ways.

The probability of alterations in human biological makeup induced by culture raises a number of important questions. By trying to eliminate genetic variants, are we weakening the gene pool by allowing people with hereditary diseases and defects to reproduce? Are we reducing chances for genetic variation by trying to control population size? We are not sure of the answers to these questions.