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MGM-31 Pershing

The MGM-31A Pershing was the missile used in the Pershing 1 and Pershing 1a field artillery missile systems. It was a solid-fueled two-stage theater ballistic missile designed and built by Martin Marietta to replace the PGM-11 Redstone missile as the primary nuclear-capable theater-level weapon of the United States Army and replaced the MGM-1 Matador cruise missiles operated by the German Air Force. Pershing later replaced the European-based MGM-13 Mace cruise missiles deployed by the United States Air Force and the German Air Force. Development began in 1958, with the first test missile fired in 1960, the Pershing 1 system deployed in 1963 and the improved Pershing 1a deployed in 1969. The U.S. Army replaced the Pershing 1a with the Pershing II Weapon System in 1983 while the German Air Force retained Pershing 1a until all Pershings were eliminated in 1991. The U.S. Army Missile Command (MICOM) managed the development and improvements while the Field Artillery Branch deployed the systems and developed tactical doctrine.

Development
George Bunker, president of the Martin Company, paid a courtesy call on General John Medaris, USA, of the Army Ballistic Missile Agency (ABMA) at Redstone Arsenal, Alabama in 1956. Medaris noted that it would be helpful to the Army if there was a missile plant near the Air Force Missile Test Center (present-day Cape Canaveral Air Force Station) in Florida. The Martin Company subsequently began construction of their Sand Lake facility in Orlando, Florida which opened in late 1957. Edward Uhl, the co-inventor of the bazooka, was the vice-president and general manager of the new factory, which continues to operate today as the Lockheed Martin Missiles and Fire Control facility.

The U.S. Army began studies in 1956 for a ballistic missile with a range of about 500 –. Later that year, Secretary of Defense Charles Erwin Wilson issued the "Wilson Memorandum" that removed from the U.S. Army all missiles with a range of 200 mi or more. The United States Department of Defense (DoD) rescinded the memorandum in 1958 and ABMA began development of the class of ballistic missile.

The missile was initially called the Redstone-S, where the S meant solid propellant (and the name Redstone came from the Redstone missile it was supposed to replace), but renamed to Pershing in honor of General of the Armies John J. Pershing. ABMA selected seven companies to develop engineering proposals: Chrysler, the Lockheed Corporation, the Douglas Aircraft Company, the Convair Division of General Dynamics, the Firestone Corp., the Sperry-Rand Company, and the Martin Company.

The Secretary of the Army, Wilber M. Brucker, the former governor of Michigan – was apparently under pressure from his home state to award the contract to a company in Michigan. Chrysler was the only contractor from Michigan, but Medaris persuaded Brucker to leave the decision entirely in the hands of the ABMA. After a selection process by General Medaris and Dr. Arthur Rudolph, the Martin Company (later Martin Marietta after a merger in 1961) was awarded a CPFF (cost-plus-fixed-fee) contract for research, development, and first production of the Pershing system under the technical supervision and concept control of the government. Martin's quality control manager for the Pershing, Phil Crosby developed the concept of Zero Defects that enhanced the production and reliability of the system.

The first launch of the XM14 R&D Pershing 1 test missile (P-01) was on 25 February 1960. The first launch from the tactical transporter erector launcher (TEL) was on 26 July 1960 (P-06). For training there was an inert Pershing 1 missile designated XM19. In June 1963, the XM14 and XM19 Pershing missiles were redesignated as XMGM-31A and XMTM-31B, respectively. The production version of the tactical missile was later designated as MGM-31A and the XMTM-31B designation was dropped.

Deployment
President Eisenhower viewed the Pershing missile when he visited Cape Canaveral on 11 February 1960, and at Fort Benning on 5 May 1960 as part of Project MAN (Modern Army Needs). President Kennedy viewed Pershing three times: as part of the inaugural parade in 1961, at Fort Bragg on 12 October 1961, and at White Sands Missile Range in 1963.

Plans were for the organization of ten missile battalions: one at Fort Sill, one in Korea and eight in West Germany; this was eventually reduced to one battalion at Fort Sill and three in West Germany.

Each missile battalion organized at Fort Sill for deployment. The first tactical Pershing unit was the 2nd Missile Battalion, 44th Artillery Regiment, followed by the 4th Missile Battalion, 41st Artillery Regiment deployed to Schwäbisch Gmünd and the 1st Missile Battalion, 81st Artillery to McCully Barracks in Wackernheim. Each missile battalion had four launchers.

The 2nd Missile Battalion, 79th Artillery Regiment formed for deployment to South Korea in February 1964. The deployment was placed on hold and the battalion supported the 56th Artillery Group and the German Air Force missile wings when they launched missiles from White Sands Missile Range. The 85th U.S. Army Field Artillery Detachment was organized in Fort Sill in November 1966 and attached to 2/79th Artillery. The deployment to Korea was canceled and the 2/79th Artillery was deactivated.

The Secretary of Defense assigned the Pershing weapon system to a Quick Reaction Alert (QRA) role in 1964 after a DoD study showed that the Pershing would be superior to tactical aircraft for the QRA mission. The German Air Force began training at Fort Sill. Each missile battalion was then authorized six launchers. In 1965 this increased to eight launchers, two per firing battery. By 1965, three U.S. Army battalions and two German Air Force wings were operational in Germany. The 579th Ordnance Company was tasked with maintenance and logistical general support for the Pershing artillery units in Germany.

Missile
Two Thiokol solid-propellant motors powered the Pershing 1 missile. Since a solid-propellant motor cannot be turned off, the missile used thrust reversal and case venting for a selective range. Splice bands and explosive bolts attached the rocket motors. The missile was controlled by an analog guidance computer using a ball-and-disk integrator and a control computer. As directed by the onboard computers, the bolts exploded and ejected the splice band. Another squib would open the thrust reversal ports in the forward end of the stage and ignite the propellant in the forward end, causing the motor to reverse direction. Testing found that the second stage would draft behind the warhead and cause it to drift off course, so explosive charges on the side of the motor opened the case and vented the propellant. The range could be graduated but the maximum was 740 km. Jet vanes in the motor nozzles and air vanes on the motor case steered the missile. The onboard analog guidance computer and the Eclipse-Pioneer ST-120 (Stable Table-120) inertial navigation system provided guidance. The warhead could be conventional explosive or a W50 nuclear weapon with three yield options— the Y1 with 60 kiloton yield, Y2 with 200 kiloton yield and Y3 with 400 kiloton yield; the conventional warhead was never deployed.

Ground equipment
The Pershing 1 firing platoon consisted of four M474 tracked-vehicles manufactured by FMC Corporation— by comparison, Redstone needed twenty vehicles. The transporter erector launcher (TEL) transported the two stages and the guidance section as an assembly and provided the launch platform after the warhead was mated. It used a removable erector launcher manufactured by Unidynamics. The warhead carrier transported the warhead, the missile fins and the azimuth laying set used to position the missile. The PTS/PS carrier transported the programmer test station (PTS) and power station (PS). A fourth vehicle transported the Radio Terminal Set. The four vehicles were known as the land train.

The PTS featured rapid missile checkout and countdowns, with complete computer control, and automatic self-test and malfunction isolation. Additionally, the PTS would perform tests that simulated airborne missile operation, programmed the trajectory of the missile and controlled the firing sequence. Plug-in micromodules increased maintainability and allowed the PTS operator to perform 80% of all repairs at the firing position. A turbine driven Power Station mounted behind the PTS, provided the primary electrical and pneumatic power and conditioned air for the missile and ground support equipment at the firing position.

Collins Radio Company produced the AN/TRC-80 Radio Terminal Set specifically for the Pershing system. The "Track 80" used an inflatable dish antenna to provide line-of-sight or tropospheric-scatter voice and teleprinter communications between missile firing units and higher headquarters. The erector-launcher, PTS, PS and RTS could be removed from the carriers and air-transported in fourteen CH-47 Chinook loads.

Orientation
The missile was positioned or laid in on a pre-surveyed site with a system of two theodolites and a target card. Directional control passed from one theodolite to the one next to the missile. The missile then oriented to north by an operator using a horizontal laying theodolite aimed at a window in the guidance section of the missile. Using a control box, the ST-120 inertial navigation system in the guidance section rotated into alignment and the north direction programmed into the computer.

Satellite launcher
In 1961, Martin proposed a satellite launch system based on the Pershing. Named Pegasus, it would have had a lighter, simplified guidance section and a short third stage booster. A 60 lb payload could be boosted to a 210 mi circular orbit, or to an elliptical orbit with a 700 mi apogee. Pegasus would have used the Pershing erector-launcher and could be placed in any open area. Martin seems to have targeted the nascent European space program, but this system was never developed.

APL
In 1965, the Army contracted with the Applied Physics Laboratory (APL) of Johns Hopkins University to develop and implement a test and evaluation program. APL provided technical support to the Pershing Operational Test Unit (POTU), identified problem areas and improved the performance and survivability of the Pershing systems.

Development
In 1964 a series of operational tests and follow-on tests were performed to determine Pershing reliability. The Secretary of Defense then requested that the Army define the modifications required to make Pershing suitable for the Quick Reaction Alert (QRA) role. The Pershing 1a development program was approved in 1965, the original Pershing renamed to Pershing 1 and Martin Marietta received the Pershing 1a production contract in 1967. Project SWAP replaced all the Pershing equipment in Germany by mid-1970 and the first units quickly achieved QRA status. Secretary of Defense Robert McNamara directed that the U.S. Air Force's MGM-13 Mace missile would be replaced by the Pershing 1a in 1965.

Pershing 1a was a Quick Reaction Alert system and so had faster vehicles, launch times and newer electronics. The total number of launchers increased from 8 to 36 per battalion. Production of the Pershing 1a missile ended in 1975 and reopened in 1977 to replace missiles expended in training.

Pershing 1a was further improved in 1971 with the Pershing Missile and Power Station Development Program. The analog guidance computer and the control computer in the missile were replaced by a single digital guidance and control computer. The main distributor in the missile that routed power and signals was replaced with a new version. The missile used a rotary inverter to convert DC to AC that was replaced by a solid-state static inverter. The power station was improved for accessibility and maintenance. Further improvements in 1976 allowed the firing of a platoon's three missiles in quick succession and from any site without the need for surveying. The Automatic Reference System (ARS) used an optical laser link and a north-seeking gyro with encode to eliminate the need for pre-selected and surveyed points. The Sequential Launch Adapter connected the PTS to three missiles, eliminating the need to cable and uncable each launcher.

A total of 754 MGM-31A missiles were built.

Deployment
The battalions in Europe reorganized under a new table of organization and equipment (TOE); an infantry battalion was added to provide additional security; and the 56th Artillery Group was reorganized and redesignated the 56th Field Artillery Brigade. Due to the nature of the weapon system, officer positions were increased by one grade: batteries were commanded by a major instead of a captain; battalions were commanded by a colonel; and the brigade was commanded by a brigadier general.

Pershing 1a was deployed with three U.S. battalions in Europe and two German Air Force wings. Each battalion or wing had 36 mobile launchers. The constitution of West Germany prohibited owning nuclear weapons, thus control of the nuclear warheads remained in the hands of the U.S. Army. During peacetime operations, a portion of the Pershing 1a assets were deployed on the QRA mission. The remainder would be conducting field training or were maintained in kasernes awaiting alert. The system was designed to be highly mobile, permitting its dispersal to clandestine sites in times of alert or war and was deployed at distances greater than 100 km behind the forward edge of battle area or political border. Owing to its mobility and setback, Pershing was considered one of the most survivable theater nuclear weapons ever deployed in Europe.

The primary mission in the Supreme Allied Commander, Europe scheduled plan took one of two forms: peacetime or an increased state of readiness called the period of tension. Different levels or techniques of tasking were used for these mission forms. The peacetime Quick Reaction Alert role required that for each battalion or wing, one firing battery or a portion thereof would be combat alert status (CAS) on a permanent hard site, covering assigned targets.

In peacetime the four batteries of each battalion rotated through four states or conditions of alert readiness, the highest being that of the CAS battery. The purpose of this rotation was to assume the CAS status, to share the burden of CAS responsibility, to provide time for field tactical training and equipment maintenance, and to give ample leave and pass time to personnel without adverse impact on operational requirements.

During periods of increased tension, the firing batteries of each battalion were deployed to previously unused field tactical sites. At these sites, they assumed responsibility for coverage of all assigned targets. During the transition from the peacetime to full combat status, coverage was maintained on the highest priority targets that were assigned to the peacetime CAS batteries.

Once all firing batteries were at their field sites, the firing elements of the battalions were deployed by platoons, which were then separated from each other geographically to reduce vulnerability. The platoons then moved to new firing positions on a random schedule to increase survivability.

Launcher and support equipment
The M790 erector launcher (EL) was a modified low-boy flat-bed trailer towed by a Ford M757 5-ton tractor. The erection booms used a 3,000 psi pneumatic over hydraulic system that could erect the five ton missile from horizontal to vertical in nine seconds. Due to the overall missile length and for security, the warhead was not mated during travel. It was stored in a carrier and mated using a hand-pumped davit after the launcher was emplaced. The EL was pulled by a Ford M757 tractor for U.S. Army units and by a Magirus-Deutz Jupiter 6×6 for German Air Force units.

The PTS and PS were mounted on a Ford M656 truck for U.S. Army units and a Magirus-Deutz or MAN SE for German Air Force units. Launch activation was performed from a remote fire box that could be deployed locally or mounted in the battery control central (BCC). One PTS controlled three launchers— when one launch count was complete, ten large cables were unplugged from the PTS and the PTS was moved up and connected to the next launcher.

Further improvements
Missile and power station upgrades in 1974 provided easier access to missile components, reduce maintenance and improved reliability. A new digital guidance and control computer combined the functions of the analog control computer and the analog guidance computer into one package. The mean time to repair decreased from 8.7 hours to 3.8 hours and the mean time between failures increased from 32 hours to 65 hours.

More modifications in 1976 greatly reduced the launch time. The sequential launch adapter (SLA) was an automatic switching device mounted in a 10-ton trailer that allowed the PTS to remain connected to all three launchers allowing all three missiles to stay hot. The automatic reference system (ARS) eliminated the theodolites previously used to lay and orient the missile. It included a north-seeking gyro and a laser link to the ST-120 that more quickly oriented the missile.

After the Pershing II explosion in 1985, the Pershing 1a launchers of the German Air Force were retrofitted with ballistic shields.

In 1987 a joint Army/Department of Energy study concluded that it was technically and financially feasible to replace the W50 warhead carried by Pershing 1a with the W85 warhead developed for Pershing II. However, with the signing of the INF Treaty, development on the conversion was terminated.

Pershing II
The Pershing II Weapon System was a solid-fueled two-stage ballistic missile designed and built by Martin Marietta to replace the Pershing 1a Field Artillery Missile System as the United States Army's primary nuclear-capable theater-level weapon. The U.S. Army replaced the Pershing 1a with the Pershing II in 1983 while the German Air Force retained Pershing 1a until all Pershings were eliminated in 1991.

Operators
🇺🇸: United States Army
 * 56th Artillery Group (1963–1970), 56th Artillery Brigade (1970–1972), 56th Field Artillery Brigade (1972–1986)
 * 1st Missile Battalion, 81st Artillery Regiment (1963–1972), 1st Battalion, 81st Field Artillery Regiment (1972–1986)
 * 3rd Missile Battalion, 84th Artillery Regiment (1963–1968), 3rd Battalion, 84th Field Artillery Regiment (1968–1986)
 * 4th Missile Battalion, 41st Artillery Regiment (1963–1971), 1st Missile Battalion, 41st Artillery Regiment (1971–1972), 1st Battalion, 41st Field Artillery Regiment (1972–1986)
 * 214th Artillery Group (1958–1972), 214th Field Artillery Group (1972–1979), 214th Field Artillery Brigade (1979–1991)
 * 2nd Missile Battalion, 44th Artillery Regiment (1962–1971), 3rd Battalion, 9th Field Artillery Regiment (1971–1990)
 * 1st Field Artillery Missile Brigade
 * 2nd Missile Battalion, 79th Artillery Regiment (1964–1968)

🇩🇪 West Germany: German Air Force
 * Missile Wing 1 (Flugkörpergeschwader 1)
 * Missile Group 12 (Flugkörpergruppe 12)
 * Missile Group 13 (Flugkörpergruppe 13)
 * Missile Wing 2 (Flugkörpergeschwader 2)
 * Missile Group 21 (Flugkörpergruppe 21)
 * Missile Group 22 (Flugkörpergruppe 22)

Elimination
The Pershing systems were eliminated after the ratification of the Intermediate-Range Nuclear Forces Treaty on 27 May 1988. The missiles began to be withdrawn in October 1988 and the last of the missiles were destroyed by the static burn of their motors and subsequently crushed in May 1991 at the Longhorn Army Ammunition Plant near Caddo Lake, Texas. Although not covered by the treaty, West Germany agreed unilaterally to the removal of the Pershing 1a missiles from its inventory in 1991, and the missiles were destroyed in the United States.

Pershing Missiles in Popular Fiction

 * Adios El Jefe! (Helmut Portmann 2024)

title: MGM-31 Pershing


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Human skin color

Human skin color ranges from the darkest brown to the lightest hues. Differences in skin color among individuals is caused by variation in pigmentation, which is the result of genetics (inherited from one's biological parents), exposure to the sun, disorders, or some combination thereof. Differences across populations evolved through natural selection or sexual selection, because of social norms and differences in environment, as well as regulations of the biochemical effects of ultraviolet radiation penetrating the skin.

The actual skin color of different humans is affected by many substances, although the single most important substance is the pigment melanin. Melanin is produced within the skin in cells called melanocytes and it is the main determinant of the skin color of darker-skin humans. The skin color of people with light skin is determined mainly by the bluish-white connective tissue under the dermis and by the hemoglobin circulating in the veins of the dermis. The red color underlying the skin becomes more visible, especially in the face, when, as consequence of physical exercise or sexual arousal, or the stimulation of the nervous system (anger, embarrassment), arterioles dilate. Color is not entirely uniform across an individual's skin; for example, the skin of the palm and the sole is lighter than most other skin, and this is especially noticeable in darker-skinned people.

There is a direct correlation between the geographic distribution of ultraviolet radiation (UVR) and the distribution of indigenous skin pigmentation around the world. Areas that receive higher amounts of UVR, generally located closer to the equator, tend to have darker-skinned populations. Areas that are far from the tropics and closer to the poles have lower intensity of UVR, which is reflected in lighter-skinned populations. By the time modern Homo sapiens evolved, all humans were dark-skinned. Some researchers suggest that human populations over the past 50,000 years have changed from dark-skinned to light-skinned and vice versa as they migrated to different UV zones, and that such major changes in pigmentation may have happened in as little as 100 generations (≈2,500 years) through selective sweeps. Natural skin color can also darken as a result of tanning due to exposure to sunlight. The leading theory is that skin color adapts to intense sunlight irradiation to provide partial protection against the ultraviolet fraction that produces damage and thus mutations in the DNA of the skin cells.

In some populations, women are significantly lighter-skinned than men. However, in other populations, notably those of European descent, men are significantly lighter-skinned than women. European women may have darker skin than European men due to the female sex hormone estrogen, which darkens light skin. Women from darker-skinned populations may have evolved to lighter skin than men so their bodies could absorb more vitamin D during pregnancy, which improves calcium absorption.

The social significance of differences in skin color has varied across cultures and over time, as demonstrated with regard to social status and discrimination.

Melanin and genes
Melanin is produced by cells called melanocytes in a process called melanogenesis. Melanin is made within small membrane–bound packages called melanosomes. As they become full of melanin, they move into the slender arms of melanocytes, from where they are transferred to the keratinocytes. Under normal conditions, melanosomes cover the upper part of the keratinocytes and protect them from genetic damage. One melanocyte supplies melanin to thirty-six keratinocytes according to signals from the keratinocytes. They also regulate melanin production and replication of melanocytes. People have different skin colors mainly because their melanocytes produce different amount and kinds of melanin.

The genetic mechanism behind human skin color is mainly regulated by the enzyme tyrosinase, which creates the color of the skin, eyes, and hair shades. Differences in skin color are also attributed to differences in size and distribution of melanosomes in the skin. Melanocytes produce two types of melanin. The most common form of biological melanin is eumelanin, a brown-black polymer of dihydroxyindole carboxylic acids, and their reduced forms. Most are derived from the amino acid tyrosine. Eumelanin is found in hair, areola, and skin, and the hair colors gray, black, blond, and brown. In humans, it is more abundant in people with dark skin. Pheomelanin, a pink to red hue is found in particularly large quantities in red hair, the lips, nipples, glans of the penis, and vagina.

Both the amount and type of melanin produced is controlled by a number of genes that operate under incomplete dominance. One copy of each of the various genes is inherited from each parent. Each gene can come in several alleles, resulting in the great variety of human skin tones. Melanin controls the amount of ultraviolet (UV) radiation from the sun that penetrates the skin by absorption. While UV radiation can assist in the production of vitamin D, excessive exposure to UV can damage health.

Time scale of skin color evolution
The earliest primate ancestors of humans most likely had pale non-pigmented skin, like our closest modern relative—the chimpanzee, and other great apes. Loss of body hair in Homo links to the thermoregulation through perspiration heat dissipation required for activity in hot open environments and endurance running. Humans as primates have a particular need for this thermoregulation since unlike other mammals they lack a carotid rete that allows precooling of blood to the brain, an organ extremely sensitive to changes in body temperature. Given endurance running and its needs for thermoregulation arose with H. erectus, this links hairlessness with the origin of H. erectus about 2 million years ago. As hominids gradually lost their fur between 1.2 and 4 million years ago, to allow for better cooling through sweating, their naked skin was exposed to sunlight. In the tropics, natural selection favoured dark-skinned human populations as high levels of skin pigmentation protected against the harmful effects of sunlight. Indigenous populations' skin reflectance (the amount of sunlight the skin reflects) and the actual UV radiation in a particular geographic area is highly correlated, which supports this idea. Genetic evidence also supports this notion, demonstrating that around 1.2 million years ago there was a strong evolutionary pressure which acted on the development of dark skin pigmentation in early members of the genus Homo. Hairlessness exposes folate circulating subcutaneously and in the dermis to degradation from UV-radiation. The effect of sunlight on folic acid levels has been crucial in the development of dark skin and favored the emergence of skin pigmentation in order to protect from folate depletion due to the increased exposure to sunlight.

In 2017, a study showed that both dark and light pigmentation alleles arose before the origin of modern humans, with the older version of the variants in many cases being associated with lighter skin.

With the evolution of hairless skin, abundant sweat glands, and skin rich in melanin, early humans could walk, run, and forage for food for long periods of time under the hot sun without brain damage due to overheating, giving them an evolutionary advantage over other species. Research on the MC1R alleles using assumptions about past population size and an absence of population bottlenecks suggests the allele for dark skin present in modern Africans arose at least by 1.2 million years ago.

This was the genotype inherited by anatomically modern humans, but retained only by part of the extant populations, thus forming an aspect of human genetic variation. About 100,000–70,000 years ago, some anatomically modern humans (Homo sapiens) began to migrate away from the tropics to the north where they were exposed to less intense sunlight. This was possibly in part due to the need for greater use of clothing to protect against the colder climate. Under these conditions there was less photodestruction of folate and so the evolutionary pressure working against the survival of lighter-skinned gene variants was reduced. In addition, lighter skin is able to generate more vitamin D (cholecalciferol) than darker skin, so it would have represented a health benefit in reduced sunlight if there were limited sources of vitamin D. Hence the leading hypothesis for the evolution of human skin color proposes that:
 * 1) From the origin of hairlessness and exposure to UV-radiation to less than 100,000 years ago, archaic humans, including archaic Homo sapiens, were dark-skinned.
 * 2) As some Homo sapiens populations began to migrate, the evolutionary constraint keeping skin dark decreased proportionally to the distance north a population migrated, resulting in a range of skin tones within northern populations, although the bulk of humans remained dark-skinned.
 * 3) At some point, some northern populations experienced positive selection for lighter skin due to the increased production of vitamin D from sunlight and the genes for darker skin disappeared from these populations.
 * 4) Subsequent migrations into different UV environments and admixture between populations have resulted in the varied range of skin pigmentations we see today.

The genetic mutations leading to light skin, though partially different among East Asians and Western Europeans, suggest the two groups experienced a similar selective pressure after settlement in northern latitudes.

The theory is partially supported by a study into the SLC24A5 gene which found that the allele associated with light skin in Europe "determined […] that 18,000 years had passed since the light-skin allele was fixed in Europeans" but may have originated as recently as 12,000–6,000 years ago "given the imprecision of method", which is in line with the earliest evidence of farming.

Research by Nina Jablonski suggests that an estimated time of about 10,000 to 20,000 years is enough for human populations to achieve optimal skin pigmentation in a particular geographic area but that development of ideal skin coloration may happen faster if the evolutionary pressure is stronger, even in as little as 100 generations. The length of time is also affected by cultural practices such as food intake, clothing, body coverings, and shelter usage which can alter the ways in which the environment affects populations.

Population and admixture studies suggest a three-way model for the evolution of human skin color, with dark skin evolving in early Homo sapiens in Africa and light skin evolving only recently after modern humans had expanded out of Africa. For the most part, the evolution of light skin has followed different genetic paths in Western and Eastern Eurasian populations; however, some mutations associated with lighter skin have estimated origin dates after humans spread out of Africa but before the divergence of the two lineages.

According to Crawford et al. (2017), most of the genetic variants associated with light and dark pigmentation in African populations appear to have originated more than 300,000 years ago. African, South Asian and Australo-Melanesian populations also carry derived alleles for dark skin pigmentation that are not found in Europeans or East Asians. Huang et al. 2021 found the existence of "selective pressure on light pigmentation in the ancestral population of Europeans and East Asians", prior to their divergence from each other. Skin pigmentation was also found to be affected by directional selection towards darker skin among Africans, as well as lighter skin among Eurasians. Crawford et al. (2017) similarly found evidence for selection towards light pigmentation prior to the divergence of West Eurasians and East Asians.

Functional considerations
Elias et. al. in 2010 showed a superior barrier function in darkly pigmented skin. Most protective functions of the skin, including the permeability barrier and the antimicrobial barrier, reside in the stratum corneum and the researchers surmise that the stratum corneum has undergone the most genetic change since the loss of human body hair. Natural selection would have favored mutations that protect this essential barrier; one such protective adaptation is the pigmentation of interfollicular epidermis, because it improves barrier function as compared to non-pigmented skin. The authors argue that lack of significant differences between modern light-skinned and dark-skinned populations in vitamin D deficiency, early death from UV-induced cancers and birth defects — as well as instances of light and dark populations living side-by-side in areas with similar UV — suggest the standard model is insufficient to explain the strong selection drive for pigmented skin. Jablonski rejects this theory on the grounds that the human tanning response is driven by UV-B exposure, not xeric stress, and that the positive selection for vitamin D production is "well-established".

Genetics
To some extent, skin color is determined independently of eye and hair color, as can be seen from variation in skin coloration in human populations. For the evolution of human skin color, see section above.

For skin color, heritability is very high, even though it can be modified by exposure to sunlight.

A recent systematic study found 169 genes involved in human skin coloration. Most of the genes were involved in melanosome biogenesis, endosomal transport, and gene regulation. Notably, the function of these genes was verified in tissue culture experiments using CRISPR-Cas9 knockouts, showing that these genes are indeed involved in melanin production.

Dark skin
All modern humans share a common ancestor who lived around 200,000 years ago in Africa. Comparisons between known skin pigmentation genes in chimpanzees and modern Africans show that dark skin evolved along with the loss of body hair about 1.2 million years ago and that this common ancestor had dark skin. Investigations into dark-skinned populations in South Asia and Melanesia indicate that skin pigmentation in these populations is due to the preservation of this ancestral state and not due to new variations on a previously lightened population.

MC1R
The melanocortin 1 receptor (MC1R) gene is primarily responsible for determining whether pheomelanin and eumelanin are produced in the human body. Research shows at least 10 differences in MC1R between African and chimpanzee samples and that the gene has probably undergone a strong positive selection (a selective sweep) in early Hominins around 1.2 million years ago. This is consistent with positive selection for the high-eumelanin phenotype seen in Africa and other environments with high UV exposure.

Light skin
For the most part, the evolution of light skin has followed different genetic paths in European and East Asian populations. Two genes, however, KITLG and ASIP, have mutations associated with lighter skin that have high frequencies in both European and East Asian populations. They are thought to have originated after humans spread out of Africa but before the divergence of the European and Asian lineages around 30,000 years ago. Two subsequent genome-wide association studies found no significant correlation between these genes and skin color, and suggest that the earlier findings may have been the result of incorrect correction methods and small panel sizes, or that the genes have an effect too small to be detected by the larger studies.

KITLG
The KIT ligand (KITLG) gene is involved in the permanent survival, proliferation and migration of melanocytes. A mutation in this gene, A326G (rs642742 ), has been positively associated with variations of skin color in African-Americans of mixed West African and European descent and is estimated to account for 15–20% of the melanin difference between African and European populations. This allele shows signs of strong positive selection outside Africa and occurs in over 80% of European and Asian samples, compared with less than 10% in African samples.

ASIP
Agouti signalling peptide (ASIP) acts as an inverse agonist, binding in place of alpha-MSH and thus inhibiting eumelanin production. Studies have found two alleles in the vicinity of ASIP are associated with skin color variation in humans. One, rs2424984, has been identified as an indicator of skin reflectance in a forensics analysis of human phenotypes across Caucasian, African-American, South Asian, East Asian, Hispanic and Native American populations and is about three times more common in non-African populations than in Africa. The other allele, 8188G (rs6058017 ) is significantly associated with skin color variation in African-Americans and the ancestral version occurs in only 12% of European and 28% of East Asian samples compared with 80% of West African samples.

Europe
A number of genes have been positively associated with the skin pigmentation difference between European and non-European populations. Mutations in SLC24A5 and SLC45A2 are believed to account for the bulk of this variation and show very strong signs of selection. A variation in TYR has also been identified as a contributor.

Research indicates the selection for the light-skin alleles of these genes in Europeans is comparatively recent, having occurred later than 20,000 years ago and perhaps as recently as 12,000 to 6,000 years ago. In the 1970s, Luca Cavalli-Sforza suggested that the selective sweep that rendered light skin ubiquitous in Europe might be correlated with the advent of farming and thus have taken place only around 6,000 years ago; This scenario found support in a 2014 analysis of mesolithic (7,000 years old) hunter-gatherer DNA from La Braña, Spain, which showed a version of these genes not corresponding with light skin color. In 2015 researchers analysed for light skin genes in the DNA of 94 ancient skeletons ranging from 8,000 to 3,000 years old from Europe and Russia. They found c. 8,000-year-old hunter-gatherers in Spain, Luxembourg, and Hungary were dark skinned while similarly aged hunter gatherers in Sweden were light skinned (having predominately derived alleles of SLC24A5, SLC45A2 and also HERC2/OCA2). Neolithic farmers entering Europe at around the same time were intermediate, being nearly fixed for the derived SLC24A5 variant but only having the derived SLC45A2 allele in low frequencies. The SLC24A5 variant spread very rapidly throughout central and southern Europe from about 8,000 years ago, whereas the light skin variant of SLC45A2 spread throughout Europe after 5,800 years ago.

Some authors have expressed caution regarding the skin pigmentation predictions. According to Ju et al. (2021), in a study addressing 40,000 years of modern human history, stated:"'Relatively dark skin pigmentation in Early Upper Paleolithic Europe would be consistent with those populations being relatively poorly adapted to high-latitude conditions as a result of having recently migrated from lower latitudes. On the other hand, although we have shown that these populations carried few of the light pigmentation alleles that are segregating in present-day Europe, they may have carried different alleles that we cannot now detect.'"

SLC24A5
Solute carrier family 24 member 5 (SLC24A5) regulates calcium in melanocytes and is important in the process of melanogenesis. The SLC24A5 gene's derived Ala111Thr allele (rs1426654 ) has been shown to be a major factor in light skin pigmentation and is common in Western Eurasia. Recent studies have found that the variant represents as much as 25–40% of the average skin tone difference between Europeans and West Africans. This derived allele is a reliable predictor of phenotype across a range of populations. It has been the subject of recent selection in Western Eurasia, and is fixed in European populations.

SLC45A2
Solute carrier family 45 member 2 (SLC45A2 or MATP) aids in the transport and processing of tyrosine, a precursor to melanin. It has also been shown to be one of the significant components of the skin color of modern Europeans through its Phe374Leu (rs16891982 ) allele that has been directly correlated with skin color variation across a range of populations. This variation is ubiquitous in European populations but extremely rare elsewhere and shows strong signs of selection.

TYR
The TYR gene encodes the enzyme tyrosinase, which is involved in the production of melanin from tyrosine. It has an allele, Ser192Tyr (rs1042602 ), found solely in 40–50% of Europeans and linked to light-colored skin in studies of South Asian and African-American populations.

East Asia
A number of genes known to affect skin color have alleles that show signs of positive selection in East Asian populations. Of these, only OCA2 has been directly related to skin color measurements, while DCT, MC1R and ATRN are marked as candidate genes for future study.

OCA2
Oculocutaneous albinism II (OCA2) assists in the regulation of pH in melanocytes. The OCA2 gene's derived His615Arg (rs1800414 ) allele has been shown to account for about 8% of the skin tone difference between African and East Asian populations in studies of an East Asian population living in Toronto and a Chinese Han population. This variant is essentially restricted to East Asia, with highest frequencies in Eastern East Asia (49–63%), midrange frequencies in Southeast Asia, and the lowest frequencies in Western China and some Eastern European populations.

Candidate genes
A number of studies have found genes linked to human skin pigmentation that have alleles with statistically significant frequencies in Chinese and East Asian populations. While not linked to measurements of skin tone variation directly, dopachrome tautomerase (DCT or TYRP2 rs2031526 ), melanocortin 1 receptor (MC1R) Arg163Gln (rs885479 ) and attractin (ATRN ) have been indicated as potential contributors to the evolution of light skin in East Asian populations.

Tanning response
Tanning response in humans is controlled by a variety of genes. MC1R variants Arg151Sys (rs1805007 ), Arg160Trp (rs1805008 ), Asp294Sys (rs1805009 ), Val60Leu (rs1805005 ) and Val92Met (rs2228479 ) have been associated with reduced tanning response in European and/or East Asian populations. These alleles show no signs of positive selection and only occur in relatively small numbers, reaching a peak in Europe with around 28% of the population having at least one allele of one of the variations. A study of self-reported tanning ability and skin type in American non-Hispanic Caucasians found that SLC24A5 Phe374Leu is significantly associated with reduced tanning ability and also associated TYR Arg402Gln (rs1126809 ), OCA2 Arg305Trp (rs1800401 ) and a 2-SNP haplotype in ASIP (rs4911414 and rs1015362 ) to skin type variation within a "fair/medium/olive" context.

Albinism
Oculocutaneous albinism (OCA) is a lack of pigment in the eyes, skin and sometimes hair that occurs in a very small fraction of the population. The four known types of OCA are caused by mutations in the TYR, OCA2, TYRP1, and SLC45A2 genes.

Age
In hominids, the parts of the body not covered with hair, like the face and the back of the hands, start out pale in infants and turn darker as the skin is exposed to more sun. All human babies are born pale, regardless of what their adult color will be. In humans, melanin production does not peak until after puberty.

The skin of children becomes darker as they go through puberty and experience the effects of sex hormones. This darkening is especially noticeable in the skin of the nipples, the areola of the nipples, the labia majora in females, and the scrotum in males. In some people, the armpits become slightly darker during puberty. The interaction of genetic, hormonal, and environmental factors on skin coloration with age is still not adequately understood, but it is known that men are at their darkest baseline skin color around the age of 30, without considering the effects of tanning. Around the same age, women experience darkening of some areas of their skin.

Human skin color fades with age. Humans over the age of thirty experience a decrease in melanin-producing cells by about 10% to 20% per decade as melanocyte stem cells gradually die. The skin of face and hands has about twice the amount of pigment cells as unexposed areas of the body, as chronic exposure to the sun continues to stimulate melanocytes. The blotchy appearance of skin color in the face and hands of older people is due to the uneven distribution of pigment cells and to changes in the interaction between melanocytes and keratinocytes.

Sexual dimorphism
It has been observed that females are found to have lighter skin pigmentation than males in some studied populations. However, in light skinned populations, namely those of European descent, women have darker skin (and eyes) than men.

It is unknown why skin color is sexually dimorphic in some populations. White women may have darker skin than white men because the female sex hormone estrogen is known to increase skin pigmentation in lighter-skinned populations. White women's skin is significantly darker than White men's, to the extent that White women have a much lower rate of skin cancer than White men.

In populations where women have lighter skin than men, it has been hypothesized that the requirement for high amounts of calcium during pregnancy and lactation may be related to the dimorphism. Breastfeeding newborns, whose skeletons are growing, require high amounts of calcium intake from the mother's milk (about 4 times more than during prenatal development), part of which comes from reserves in the mother's skeleton. Adequate vitamin D resources are needed to absorb calcium from the diet, and it has been shown that deficiencies of vitamin D and calcium increase the likelihood of various birth defects such as spina bifida and rickets. Natural selection may have led to females with lighter skin than males in some indigenous populations because women must get enough vitamin D and calcium to support the development of fetus and nursing infants and to maintain their own health. However, some authors have cast doubt on the theory that vitamin D synthesis is related to the sexual dimorphism of human akin color in these populations.

The sexes also differ in how they change their skin color with age. Women can change pigmentation in certain parts of their body, such as the areola and nipples during the menstrual cycle and pregnancy. Between 50 and 70% of pregnant women will develop the "mask of pregnancy", which refers to the browning and yellowing of the cheeks, upper lips, and forehead that occurs during pregnancy. This is caused by increases in the female sex hormone estrogen, and it can develop in women who take birth control pills or participate in hormone replacement therapy.

Disorders of pigmentation
Uneven pigmentation of some sort affects most people, regardless of bioethnic background or skin color. Skin may either appear lighter, or darker than normal, or lack pigmentation at all; there may be blotchy, uneven areas, patches of brown to gray discoloration or freckling. Apart from blood-related conditions such as jaundice, carotenosis, or argyria, skin pigmentation disorders generally occur because the body produces either too much or too little melanin.

Albinism
Some types of albinism affect only the skin and hair, while other types affect the skin, hair and eyes, and in rare cases only the eyes. All of them are caused by different genetic mutations. Albinism is a recessively inherited trait in humans where both pigmented parents may be carriers of the gene and pass it down to their children. Each child has a 25% chance of being albino and a 75% chance of having normally pigmented skin. One common type of albinism is oculocutaneous albinism or OCA, which has many subtypes caused by different genetic mutations. Albinism is a serious problem in areas of high sunlight intensity, leading to extreme sun sensitivity, skin cancer, and eye damage.

Albinism is more common in some parts of the world than in others, but it is estimated that 1 in 70 humans carry the gene for OCA. The most severe type of albinism is OCA1A, which is characterized by complete, lifelong loss of melanin production, other forms of OCA1B, OCA2, OCA3, OCA4, show some form of melanin accumulation and are less severe. The four known types of OCA are caused by mutations in the TYR, OCA2, TYRP1, and SLC45A2 genes.

Albinos often face social and cultural challenges (even threats), as the condition is often a source of ridicule, racism, fear, and violence. Many cultures around the world have developed beliefs regarding people with albinism. Albinos are persecuted in Tanzania by witchdoctors, who use the body parts of albinos as ingredients in rituals and potions, as they are thought to possess magical power.

Vitiligo
Vitiligo is a condition that causes depigmentation of sections of skin. It occurs when melanocytes die or are unable to function. The cause of vitiligo is unknown, but research suggests that it may arise from autoimmune, genetic, oxidative stress, neural, or viral causes. The incidence worldwide is less than 1%. Individuals affected by vitiligo sometimes suffer psychological discomfort because of their appearance.

Hyperpigmentation
Increased melanin production, also known as hyperpigmentation, can be a few different phenomena:
 * Melasma describes the darkening of the skin.
 * Chloasma describes skin discolorations caused by hormones. These hormonal changes are usually the result of pregnancy, birth control pills or estrogen replacement therapy.
 * Solar lentigo, also known as "liver spots" or "senile freckles", refers to darkened spots on the skin caused by aging and the sun. These spots are quite common in adults with a long history of unprotected sun exposure.

Aside from sun exposure and hormones, hyperpigmentation can be caused by skin damage, such as remnants of blemishes, wounds or rashes. This is especially true for those with darker skin tones.

The most typical cause of darkened areas of skin, brown spots or areas of discoloration is unprotected sun exposure. Once incorrectly referred to as liver spots, these pigment problems are not connected with the liver.

On lighter to medium skin tones, solar lentigenes emerge as small- to medium-sized brown patches of freckling that can grow and accumulate over time on areas of the body that receive the most unprotected sun exposure, such as the back of the hands, forearms, chest, and face. For those with darker skin colors, these discolorations can appear as patches or areas of ashen-gray skin.

Exposure to the sun
Melanin in the skin protects the body by absorbing solar radiation. In general, the more melanin there is in the skin the more solar radiation can be absorbed. Excessive solar radiation causes direct and indirect DNA damage to the skin and the body naturally combats and seeks to repair the damage and protect the skin by creating and releasing further melanin into the skin's cells. With the production of the melanin, the skin color darkens, but can also cause sunburn. The tanning process can also be created by artificial UV radiation.

There are two different mechanisms involved. Firstly, the UVA-radiation creates oxidative stress, which in turn oxidizes existing melanin and leads to rapid darkening of the melanin, also known as IPD (immediate pigment darkening). Secondly, there is an increase in production of melanin known as melanogenesis. Melanogenesis leads to delayed tanning and first becomes visible about 72 hours after exposure. The tan that is created by an increased melanogenesis lasts much longer than the one that is caused by oxidation of existing melanin. Tanning involves not just the increased melanin production in response to UV radiation but the thickening of the top layer of the epidermis, the stratum corneum.

A person's natural skin color affects their reaction to exposure to the sun. Generally, those who start out with darker skin color and more melanin have better abilities to tan. Individuals with very light skin and albinos have no ability to tan. The biggest differences resulting from sun exposure are visible in individuals who start out with moderately pigmented brown skin: the change is dramatically visible as tan lines, where parts of the skin which tanned are delineated from unexposed skin.

Modern lifestyles and mobility have created mismatch between skin color and environment for many individuals. Vitamin D deficiencies and UVR overexposure are concerns for many. It is important for these people individually to adjust their diet and lifestyle according to their skin color, the environment they live in, and the time of year. For practical purposes, such as exposure time for sun tanning, six skin types are distinguished following Fitzpatrick (1975), listed in order of decreasing lightness:

Fitzpatrick scale
The following list shows the six categories of the Fitzpatrick scale in relation to the 36 categories of the older von Luschan scale:

Dark skin with large concentrations of melanin protects against ultraviolet light and skin cancers; light-skinned people have about a tenfold greater risk of dying from skin cancer, compared with dark-skinned persons, under equal sunlight exposure. Furthermore, UV-A rays from sunlight are believed to interact with folic acid in ways that may damage health. In a number of traditional societies the sun was avoided as much as possible, especially around noon when the ultraviolet radiation in sunlight is at its most intense. Midday was a time when people stayed in the shade and had the main meal followed by a nap, a practice similar to the modern siesta.

Geographic variation
Approximately 10% of the variance in skin color occurs within regions, and approximately 90% occurs between regions. Because skin color has been under strong selective pressure, similar skin colors can result from convergent adaptation rather than from genetic relatedness; populations with similar pigmentation may be genetically no more similar than other widely separated groups. Furthermore, in some parts of the world where people from different regions have mixed extensively, the connection between skin color and ancestry has substantially weakened. In Brazil, for example, skin color is not closely associated with the percentage of recent African ancestors a person has, as estimated from an analysis of genetic variants differing in frequency among continent groups.

In general, people living close to the equator are highly darkly pigmented, and those living near the poles are generally very lightly pigmented. The rest of humanity shows a high degree of skin color variation between these two extremes, generally correlating with UV exposure. The main exception to this rule is in the New World, where people have only lived for about 10,000 to 15,000 years and show a less pronounced degree of skin pigmentation.

In recent times, humans have become increasingly mobile as a consequence of improved technology, domestication, environmental change, strong curiosity, and risk-taking. Migrations over the last 4000 years, and especially the last 400 years, have been the fastest in human history and have led to many people settling in places far away from their ancestral homelands. This means that skin colors today are not as confined to geographical location as they were previously.

Social status, colorism and racism
According to classical scholar Frank Snowden, skin color did not determine social status in ancient Egypt, Greece or Rome. These ancient civilizations viewed relations between the major power and the subordinate state as more significant in a person's status than their skin colors.

Nevertheless, some social groups favor specific skin coloring. The preferred skin tone varies by culture and has varied over time. A number of indigenous African groups, such as the Maasai, associated pale skin with being cursed or caused by evil spirits associated with witchcraft. They would abandon their children born with conditions such as albinism and showed a sexual preference for darker skin.

Many cultures have historically favored lighter skin for women. Before the Industrial Revolution, inhabitants of the continent of Europe preferred pale skin, which they interpreted as a sign of high social status. The poorer classes worked outdoors and got darker skin from exposure to the sun, while the upper class stayed indoors and had light skin. Hence light skin became associated with wealth and high position. Women would put lead-based cosmetics on their skin to whiten their skin tone artificially. However, when not strictly monitored, these cosmetics caused lead poisoning. Other methods also aimed at achieving a light-skinned appearance, including the use of arsenic to whiten skin, and powders. Women would wear full-length clothes when outdoors, and would use gloves and parasols to provide shade from the sun.

Colonization and enslavement as carried out by European countries became involved with colorism and racism, associated with the belief that people with dark skin were uncivilized, inferior, and should be subordinate to lighter-skinned invaders. This belief exists to an extent in modern times as well. Institutionalized slavery in North America led people to perceive lighter-skinned African-Americans as more intelligent, cooperative, and beautiful. Such lighter-skinned individuals had a greater likelihood of working as house slaves and of receiving preferential treatment from plantation owners and from overseers. For example, they had a chance to get an education. The preference for fair skin remained prominent until the end of the Gilded Age, but racial stereotypes about worth and beauty persisted in the last half of the 20th century and continue in the present day. African-American journalist Jill Nelson wrote that, "To be both prettiest and black was impossible," and elaborated:

"We learn as girls that in ways both subtle and obvious, personal and political, our value as females is largely determined by how we look. ... For black women, the domination of physical aspects of beauty in women's definition and value render us invisible, partially erased, or obsessed, sometimes for a lifetime, since most of us lack the major talismans of Western beauty. Black women find themselves involved in a lifelong effort to self-define in a culture that provides them no positive reflection."

A preference for fair or lighter skin continues in some countries, including Latin American countries where whites form a minority. In Brazil, a dark-skinned person is more likely to experience discrimination. Many actors and actresses in Latin America have European features—blond hair, blue eyes, and pale skin. ; ; ; ; ; ; A light-skinned person is more privileged and has a higher social status; a person with light skin is considered more beautiful and lighter skin suggests that the person has more wealth. Skin color is such an obsession in some countries that specific words describe distinct skin tones - from (for example) "jincha", Puerto Rican slang for "glass of milk" to "morena", literally "brown".

In South Asia, society regards fair skin as more attractive and associates dark skin with lower class status; this results in a massive market for skin-whitening creams. Fairer skin-tones also correlate to higher caste-status in the Hindu social order—although the system is not based on skin tone. Actors and actresses in Indian cinema tend to have light skin tones, and Indian cinematographers have used graphics and intense lighting to achieve more "desirable" skin tones. Fair skin tones are advertised as an asset in Indian marketing.

Skin-whitening products have remained popular over time, often due to historical beliefs and perceptions about fair skin. Sales of skin-whitening products across the world grew from $40 billion to $43 billion in 2008. In South and East Asian countries, people have traditionally seen light skin as more attractive, and a preference for lighter skin remains prevalent. In ancient China and Japan, for example, pale skin can be traced back to ancient drawings depicting women and goddesses with fair skin tones. In ancient China, Japan, and Southeast Asia, pale skin was seen as a sign of wealth. Thus skin-whitening cosmetic products are popular in East Asia. Four out of ten women surveyed in Hong Kong, Malaysia, the Philippines and South Korea used a skin-whitening cream, and more than 60 companies globally compete for Asia's estimated $18 billion market. Changes in regulations in the cosmetic industry led to skin-care companies introducing harm-free skin lighteners. In Japan, the geisha have a reputation for their white-painted faces, and the appeal of the bihaku (美白), or "beautiful white", ideal leads many Japanese women to avoid any form of tanning. There are exceptions to this, with Japanese fashion trends such as ganguro emphasizing tanned skin. Skin whitening is also not uncommon in Africa, and several research projects have suggested a general preference for lighter skin in the African-American community. In contrast, one study on men of the Bikosso tribe in Cameroon found no preference for attractiveness of females based on lighter skin color, bringing into question the universality of earlier studies that had exclusively focused on skin-color preferences among non-African populations.

Significant exceptions to a preference for lighter skin started to appear in Western culture in the mid-20th century. However, a 2010 study found a preference for lighter-skinned women in New Zealand and California. Though sun-tanned skin was once associated with the sun-exposed manual labor of the lower class, the associations became dramatically reversed during this time—a change usually credited to the trendsetting Frenchwoman Coco Chanel (1883–1971) presenting tanned skin as fashionable, healthy, and luxurious. , though an overall preference for lighter skin remains prevalent in the United States, many within the country regard tanned skin as both more attractive and healthier than pale or very dark skin. Western mass media and popular culture continued to reinforce negative stereotypes about dark skin, but in some circles pale skin has become associated with indoor office-work while tanned skin has become associated with increased leisure time, sportiness and good health that comes with wealth and higher social status. Studies have also emerged indicating that the degree of tanning is directly related to how attractive a young woman is.

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

title: Human skin color


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Harry Enfield

Henry Richard Enfield (born 30 May 1961) is an English comedian, actor, writer and director. He is known in particular for his television work, including Harry Enfield's Television Programme and Harry & Paul, and for the creation and portrayal of comedy characters such as Kevin the Teenager, Loadsamoney, Smashie and Nicey, The Scousers, Tim Nice-But-Dim and Mr "You Don't Want to Do It Like That".

Early life
Born in Horsham, Sussex, he is the eldest of four children (and only son) of English television, radio and newspaper journalist and presenter Edward Enfield and his wife, Deirdre Jenkins. The Enfield family are descendants of the nineteenth-century philanthropist Edward Enfield.

He was educated at the independent Arundale School in Pulborough, Dorset House School, Worth School, Collyer's Sixth Form College (all in West Sussex) and the University of York, where he was a member of Derwent College and studied politics. He squatted in Hackney and worked for a while as a milkman.

Career
Enfield first came to wide public attention when appearing on Channel 4's Saturday Live as several different characters created with Paul Whitehouse. These quickly entered the national consciousness. Among these characters were Stavros, a Greek kebab shop owner with fractured English; and Loadsamoney, an obnoxious plasterer who constantly boasted about how much money he earned. The Loadsamoney character was created in reaction to the policies of the Thatcher government of the day, and took on a life of its own, sampling the songs "Money, Money" from the musical Cabaret and "Money, Money, Money" by ABBA to spawn a hit single in 1988 and a sell-out live tour. In May 1988, Labour Party leader Neil Kinnock used the term loadsamoney to criticise the policies of the Conservative government and journalists began to refer to the "loadsamoney mentality" and the "loadsamoney economy".

As a foil to Loadsamoney, Enfield and Whitehouse created the Geordie "Bugger-All-Money" and in 1988 Enfield appeared as both characters during the Nelson Mandela 70th Birthday Tribute Concert at Wembley Stadium. In time, Whitehouse and Enfield became disturbed that Loadsamoney was being seen in a positive light, rather than as a satirical figure, and they had him run over during a Comic Relief Red Nose Day show while leaving the studio after presenting host Lenny Henry with "the biggest cheque of the night"—a physically huge cheque for ten pence. Enfield created "Tory Boy", a character which portrayed a young male Conservative Member of Parliament (MP).

In 1989, Enfield realised a personal project, Norbert Smith - a Life, a spoof on British theatrical knights "slumming" in the film industry. He also provided voices for the British satirical puppet show Spitting Image, and starred as Dirk Gently in the BBC Radio adaptations of Dirk Gently's Holistic Detective Agency and The Long Dark Tea-Time of the Soul.

TV series

In 1990, Enfield developed his BBC sketch show Harry Enfield's Television Programme, later retitled Harry Enfield & Chums, with Whitehouse and Kathy Burke. Eschewing the alternative comedy style prevalent at the time, both versions of the show were indebted to comedians such as Dick Emery and Morecambe and Wise. Enfield and his co-performers created another group of nationally recognised characters for these shows, such as Stan and Pam Herbert, who use the catchphrase "We are considerably richer than you" (in an exaggerated West-Midlands accent), Tim Nice-But-Dim, The Scousers, Smashie and Nicey, Wayne and Waynetta Slob, Annoying Kid Brother, who grew into Kevin the Teenager, and two old-fashioned presenters, Mr Cholmondley-Warner and Grayson.

In 1991, Enfield played Dermot in the sitcom Men Behaving Badly along with Martin Clunes, Caroline Quentin and Leslie Ash, originally on Thames Television. Enfield left after the first series, and was replaced in the second series by Neil Morrissey as Tony. Enfield is a professed fan of opera and fronted a Channel 4 documentary series on the subject. In 1991 Harry also starred in the series Gone to the Dogs as Little Jim.

After a short break from television, Enfield signed a new contract with BSkyB, but produced only one series, Harry Enfield's Brand Spanking New Show. In 2002 Enfield returned to the BBC with Celeb, a new series based on the comic strip of the same title in Private Eye, as the ageing rockstar Gary Bloke.

In 2002, Enfield was the first guest on the revamped version of BBC's Top Gear where he did a 2 minutes 1 second lap. He also appeared on the show on 23 November 2008. Enfield has also narrated various TV documentaries such as the Discovery Wings channel "Classic British Aircraft".

In 2007, he played Jim Stonem in the Channel 4 series Skins. He reprised this role in the second series in 2008, and the third series in 2009. Enfield directed two episodes of Skins in season two entitled "Chris" and "Tony" in 2008. He appears often on mainstream television shows. His comedy series Harry & Paul (originally titled Ruddy Hell! It's Harry & Paul) started in 2007.

In September 2013 Enfield appeared in the BBC Three comedy series Bad Education as Martin, the father of Jack Whitehall's character Alfie. In October 2014, Enfield and Paul Whitehouse returned to the characters of Frank and George in a sketch for Channel 4's testicular cancer awareness comedy show "The Feeling Nuts Comedy Night".

In August 2015, Enfield, alongside Whitehouse, in celebration of their 25-year partnership, presented An Evening With Harry Enfield and Paul Whitehouse

In 2016, he appeared as John Shakespeare, father of William Shakespeare, in the sitcom Upstart Crow.

Since 2016, Enfield has appeared as Prince Charles (later King Charles III) in the Channel 4 sitcom The Windsors.

Films
In 2000, Enfield appeared in his first leading film role playing Kevin alongside Kathy Burke, who played the character's (male) friend Perry—roles originally created for Enfield's television series—in Kevin & Perry Go Large. The film charted the pair's attempt to become professional DJs by travelling to the nightclubs of Ibiza and pestering their idol, the DJ Eyeball Paul, played by Rhys Ifans, while gaining love and losing their virginity. Enfield also appeared as King George VI in Churchill: The Hollywood Years (2004), a satire on Hollywood's tendency to change elements of history. In 2012, he starred with Simon Callow in the film Acts of Gordfrey, which opened in UK cinemas on 27 January.

He reprised his role as Martin in The Bad Education Movie, released on 21 August 2015. He appeared as Bill in the 2015 film Scottish Mussel.

In 2015 Enfield and Jessica Hynes appeared as Mr and Mrs Jackson in a BBC film of the Arthur Ransome children's novel Swallows and Amazons.

In 2022, Enfield appeared as Tony Blair in the made-for-television biographical musical comedy film Prince Andrew: The Musical.

Video games
In 2012, a likeness of his character Loadsamoney, named "Harold Lott", was released as a DLC skin for the game Killing Floor.

Commercials
Enfield appeared in some television commercials before becoming famous, including one made in 1987 for Tetley. Enfield's commercials include a series made in 1994 for Dime Bar. One commercial in this series had Enfield as a yokel refusing a Dime bar—smooth on the outside, crunchy on the inside—because he preferred armadillos—smooth on the inside, crunchy on the outside. Later Enfield, with Paul Whitehouse, starred in a series of commercials for Hula Hoops as The Self-Righteous Brothers, characters from Enfield's television show. In 2004 Enfield starred in a series of commercials for Burger King in Paraguay as Dr Angus, a character intended to promote the company's newest hamburger. Two more characters from Enfield's TV series, Mr Cholmondley-Warner and Grayson, also appeared in commercials, for Mercury Communications. Also in 2004 Enfield provided the voice of "The Roaming Gnome" character used in Travelocity's U.S. advertising campaign. Enfield was also in commercials for Worthington Bitter.

Music
Enfield made a cameo appearance as 'the tea lady' during Blur's performance at the Olympics Closing Ceremony Celebration Concert in London's Hyde Park in 2012.

He also appeared alongside Damon Albarn's other project The Good, the Bad & the Queen, as compere, during a live performance at the Tower of London, on 9 July 2007.

Theatre
In 2021 Enfield starred as Prince Charles in The Windsors: Endgame at the Prince of Wales Theatre in London. The show ran for a limited time and closed on 9 October 2021.

Personal life
In 1997, Enfield married Lucy Lyster; they have three children. It was announced in August 2020 that the couple had separated.

title: Harry Enfield


text:
Heavy Equipment Transport System

Heavy Equipment Transporter System (HETS) is the name of a U.S. Army logistics vehicle transport system, the primary purpose of which is to transport the M1 Abrams tank. It is also used to transport, deploy, and evacuate armored personnel carriers, self-propelled artillery, armored bulldozers, and other heavy vehicles and equipment.

The current U.S. Army vehicle used in this role is an Oshkosh-built M1070 tractor unit in A0 and A1 configurations which is coupled to a DRS Technologies M1000 semi-trailer. This combination replaced the earlier Oshkosh-built M911 tractor unit and M747 semi-trailer.

M1070 and M1000

To meet a US Army requirement for the transport of the M1 Abrams series main battle tank (MBT) Oshkosh Truck Corporation, now Oshkosh Defense, proposed the M1070. A contract for 1,044 M1070s was placed, with production commencing in July 1992. The final U.S. Army contract for the original A0 version called for 195 vehicles. These were delivered between March 2001 and March 2003. A total of 2,488 A0 versions were delivered to the U.S. Army. Following extensive use, some M1070s have been reset to the original build standard by Oshkosh.

The M1070E1 model was developed in the mid-1990s in conjunction with the U.S. Army as a possible Technology Insertion Program (TIP) for the M1070. No orders were placed.

In March 2008, Oshkosh Defense announced a contract award from the U.S. Army to begin engineering and initial production of the next-generation of HET. Oshkosh announced in October 2010 its first delivery order for the M1070A1 HET. Production of the M1070A1 concluded in August 2014, with 1,591 new vehicles built.

The M1000 trailer is used with the M1070A0 and M1070A1 tractors. The M1000 was originally developed as a private venture by Southwest Mobile Systems, later Systems & Electronics Inc (SEI), now DRS Technologies, as a response to a possible US Army requirement for transporting M1 and M1A1 MBTs. A production order for 1,066 M1000 units was placed by the U.S. Army in 1989. By July 2009 more than 2,600 M1000 trailers had been ordered.
 * The M1070 and M1000 are both air-transportable by C-5 Galaxy or C-17 Globemaster III aircraft.
 * The M1070 replaced the Scammell Commander as the British Army heavy tank transporter in 2001. The UK version (M1070F) is compliant with European legislation on emissions (EURO III).

M25 Tank Transporter
The M25 Tank Transporter was a heavy tank transporter and tank recovery vehicle used in World War II and beyond by the US Army. Nicknamed the Dragon Wagon, the M25 was composed of a 6×6 armored tractor (M26) and 40-ton trailer (M15).

M746/M747 - M911/M747
Prior to 1993, the U.S. Army employed the Commercial Heavy Equipment Transporter (C-HET), which consisted of either the M746 or the M911 truck tractor and the M747 semitrailer.

 * The M746 was an 8×8, 221⁄2-ton tractor built by Ward LaFrance from 1975 to 1977. Approximately 125-185 were built.
 * The lift axle, 8×6, Oshkosh M911 superseded the M746 after 1977.

During Operations Desert Shield and Desert Storm the M911 vehicles were employed primarily to haul M1 Abrams tanks. However, they demonstrated poor durability when loads exceeded 60 tons. Some are still serving as heavy transports of other military equipment, such as cargo handling equipment.

Operators
• 🇪🇬 (Oshkosh M1070)

• (Oshkosh M911)

• 🇮🇶 (Oshkosh M1070)

• 🇮🇱 (DRS M1000)

• 🇯🇴 (Oshkosh M1070

• 🇲🇦 (Oshkosh M911)

• 🇴🇲 (Oshkosh M911)

• 🇸🇦 (Oshkosh M1070/Oshkosh M911)

• 🇸🇩 Sudan (Oshkosh M911)

• 🇹🇭 (Oshkosh M911)

• (Oshkosh Global HET)

• (Oshkosh 1070F)

• 🇺🇸 (Oshkosh M1070/Oshkosh M911)

• 🇾🇪 Yemen (Oshkosh M911)

title: Heavy Equipment Transport System