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Climate Change And Human Evolution!


Outside Sub-Saharan Africa: Neanderthal DNA accounts for 1–4% of modern genomes, with East Asian individuals having about 12–20% more Neanderthal ancestry than Europeans. Neanderthal genes gave humans red hair,green eyes,freckles and pale skin. No evidence of births from Neanderthal males and modern human women has ever been found.

Climate change may have had an important role in the Neanderthal extinction.” After generations of surviving the double-dose of super-cold weather which likely radically changed theevolution of the Neanderthal,global warming transforming the Arctic[like Steppes into open woodlands of central Europe, So why did Neanderthals die out during these climate shifts while modern humans survived? The researchers suggest that because Neanderthals relied heavily on protein from large game animals they had trouble adapting when climate change impacted populations of those animals.


The wooly mammoth extinction started around 40000 years ago and peaked around 12000 years ago. Scientists think climate change, habitat destruction and hunting contributed to the extinction. They were more vulnerable due to the low size of the population and the relatively low birth rate.Neanderthals are believed to have gone extinct also around 40,000 years ago.t The best-known Neanderthals lived in Eurasia until 40,000 years ago, after which all physical evidence of them disappears. It is increasingly clear that rapid warming, not sudden cold snaps, were the cause of the extinctions during the last glacial maximum. Research helps explain further the sudden disappearance of mammoths and giant sloths that became extinct around 11,000 years ago at the end of the last ice age.


Elephants lived in different habitats than Mammoths, so they weren't subjected to the same pressures. With the end of the ice age, the Tundra (and therefore the feeding grounds for the Mammoths) disappeared more and more, while the grasslands where the elephants lived in Africa weren't as affected. Causes previously suggested for the sudden extinction of Archaic Neanderthals (Homo neanderthalensis) in Europe, starting around 35,000 years ago, comprise food shortage, climatic effects and competition for food from Africa's Modern Humans. However, as soon as Neanderthals had to compete with another species that consumed the same resources increased reliance on cannibalism had a negative impact on their population, leading, in the end, to their extinction.



Climate change could trigger evolutionary changes in humans, including causing a shift in our appearance and eliminating racial differences.


We are very lucky that humans are innately adaptable creatures — and extreme heat could change our genes. Especially since recent findings show the world is on Track for 3 degree Celsius warming and there is nothing that can be done to stop it! At 3C of warming, scientists predict the world could pass several catastrophic points of no return, from the runaway melting of ice sheets to the Amazon rainforest drying out and a change in our mean global temperatures. "Present trends are racing our planet down a dead-end 3C temperature rise," said U.N. Secretary-General Antonio Guterres.


The heatwaves have reignited the debate about how we can protect people from rising temperatures – and how high we can stand them to go. But the headline figures do not give the whole story when it comes to the impact of high temperatures on humans, because humidity, which is not factored into these figures, plays a huge role in how we actually experience heat.

Recent research has found that we may actually already be nearing the threshold values for human survivability of temperature and humidity for short periods in some places of the world – a measure known as the “wet-bulb” temperature – and that this threshold may actually be far lower than previously thought.


Using data from 32 European countries for nearly 244 million live births between 1969 and 2021, a recent study examined the effects of temperatures on birth rates. The results show that exposure to hot days reduces birth rates significantly and strong negative effects are observed nine to ten months after exposure to hot temperatures. During cooler months, a partial recovery is observed, with slightly increased birth rates. This study also shows that the effect of high-humidity hot days is much stronger than that of hot days with low humidity and some adaptation to heat might be expected but only in the long run. In short massive die offs would occur until only those surviving with the ability to procreate would make up the genetics of the following generations.


How The Human Body Will Evolve With Climate Change?

Since strong sun exposure damages the body, evolution's initial solution was to evolve skin that was dark so as to protect against the sun's more damaging rays. Melanin, the skin's brown pigment, is a natural sunscreen that protects the majority of the planet's peoples from the many harmful effects of ultraviolet (UV) rays, especially fertility decline. The first homosapiens mankind's oldest common forefather was dark skinned and African, people became more pale or pheomelanin dominant as they moved further north out of Africa into colder climates with less sunlight. Scientists hypothesize this occurred so they could access vitamin D from the sun, something necessary in order to procreate. Dark-skinned people have white palms and soles, but light-skinned people have more consistent skin tones.


The Massachusetts Institute of Technology (MIT) estimates that by the end of this century, in India alone, around 2% of the population will be exposed to temperatures reaching 35 degrees (95°F) WBT (wet bulb temperature).North Indians the lighter populations of India are already seeing a massive decline in population in comparison to South Indians who are much darker in complexion due to less admixture with Europeans and the fact most indigenous people who live outside the tropical regions have lighter skin. North India is outside the tropical equatorial zone. Currently research into the genes associated with severe forms of heat stroke could, along with other research being carried out around the world, help to answer a vital human question: will our bodies be able to adapt to the devastating effects of global warming?


As in the case of north and South Indians the difference in the frequency of the allele (rs1426654). The variation of pigmentation in humans is associated with melanosomes, the pigmented organelles of melanocytes, variable in number, size, and density the more dense the darker the complexion. Such variation is related to biological effects of UV radiation since dark skin offers more protection against UV irradiation at or near the equator, and pale skin protects people from vitamin D deficiency at higher latitudes. Although it has been hypothesized that many genes contribute to produce these different color shades, little is known about the biology and functions of these genes.


What is known is that populations decline in conditions unfavorable to their survival either by disease like skin cancer or variables that affect the ability to procreate. The "wet-bulb temperature", or WBT, measures the cocktail of high heat and high humidity that is fatal to humans. At 35° WBT, humans die within a few hours, as the humidity can no longer evaporate. High wet-bulb temperatures are dangerous because humans lose around 80% of heat through sweating, so when both humidity and air temperature are high it becomes harder to shed excess heat. Sweat evaporates very slowly, if at all, in very humid conditions. This explains why people without eumelanin (darkest melanin pigment) have difficulty maintaining large populations in the tropics.


"A landmark study, co-authored by Huber in 2010 found that a wet-bulb temperature of 35C (95F) persisting beyond six hours could induce hyperthermia in people and cause serious health consequences or death."


Similarly, to our melanin content our digestive systems will evolve in response to shifts in food availability — where crops and livestock can be cultivated. The ability to digest milk in adulthood evolved among groups in the Middle East and North Africa that began raising cattle. Future generations may evolve better abilities to tolerate sugar or fat. Changing diets will also trigger changes in our microbiomes — the bacteria and other microorganisms that live in our guts and help to keep us healthy. Vegetarians tend to harbor a different mix of bacteria than meat eaters, and these changes could be exaggerated if prolonged droughts make it too costly to raise livestock for meat. We already see a major shift toward plant based foods in our supermarkets and a resurgence of gardening, farming, and foraging education in our schools.


Moderately cold temperatures increase longevity and decrease susceptibility to age-related diseases, according to research conducted at the University of Cologne. So surviving climate also involves cultural changes, such as cold showers, owning shade trees and fruit trees, learning to walk on the shaded side of the road etc. According to historical records, during the scorching summer, some West African people preferred to drink ice water, some boiled perilla leaves, and licorice as summer soup to keep off the heat. Ancient people in north Africa and the tropics also loved to make lotus seed soup in summer which was said to have the benefit of strengthening the body. Africa is a hot continent as the solar radiation intensity is always high. Therefore, they have centuries of survival knowledge for heat if not millennia!


In summation the Neanderthal allele of MC1R (a gene with mutations linked to,pale skin, freckles and red hair in modern populations) is found at a frequency of 5% in Europeans, but is present in Taiwanese Aborigines at a frequency of 70% and at 30% in other East Asian populations.MC1R variant distribution differs widely between different parts of the world. The highest frequency of R alleles is observed in Northern Europe, whereas in more sun-exposed geographic regions, R alleles are very rare. Autosomal genetic analyses found that the Sámi people received admixture from a Siberian source population, best represented by the North Asian Nganasan people, a Samoyedic people. This Siberian component is found at an average frequency of ~21% among the Sámi people. The specific Siberian like ancestry is proposed to have arrived in Northeast Europe during the early Iron Age. In contrast, European-related ancestry was also contributed to various Siberians and some East Asians during the Bronze Age. Eg. Siberians already harbored some European-related ancestry, including deep layered Paleolithic Siberians, who were actually a sister lineage of European hunter-gatherers.


The Finnish and Sami people have many common myths pertaining to ancient peoples who fit the description of Neanderthals. Large stocky musclebound and fierce people with pale skin and wild red hair who had a taste for human flesh. Two myths common to the Sami are as follows:


The first is about the stallo -- large wild-men who lived in the forest and liked the taste of human flesh, including the flesh of their own kind. In one story, a stallo girl runs away from her family because of their plans to eat her. Eventually marrying a Lappish man, she returns with her husband and newborn child on a visit to her parents. Her mother takes the baby away from her and starts to eat it, and her other child, a son, asks to eat of the baby, too. In another story, two Lappish girls marry into a stallo family, and because they can't bear children, their stallo husbands plot to eat them.


The second is about the pädnaknjunne, a folk whose noses were like a dog's muzzle, which they used to sniff out humans to eat them. Lore about the pädnaknjunne often became mixed with the Swedish hundturk and the Finnish koirankuonolainen. In all of these stories, these dog-snouted men were said to be gluttons for human flesh. Unlike the stallo, these creatures were sometimes described as very civilized: human children would be salted in barrels to be put on board ships and sold as food to traders.


Some folklorists claimed that these cannibal myths were common in Sami folklore because at some point in their ancient past they lived as neighbors to a race of cannibals. It was suggested by some to be ancestors of the Samoyeds, the Nenets who live in Western Siberia, and who were at one point believed by the Russians to be cannibals. At some point, the term Samoyed itself was argued to mean "self-eaters," from the Russian 'self' (sam) and 'to eat' (jesti), but this is now thought to be an error. There's in fact no evidence that they ever practiced cannibalism, either. The Samoyeds were known, however, to eat raw reindeer meat, particularly at ceremonies, and its been argued that this enjoyment of the raw flesh was spun into stories of cannibalism.


Some now think the term Samoyed is derived from Saami, because the two peoples were closely related.


Some have also suggested that legends about the stallo came from bands of Vikings and robbers who moved around in mountains and lived by stealing reindeer. This is because there are many stallo stories where they're described as armed with a long knife, and having kept silver possessions. Because in stories stallo married the Sami, its believed some people are half-stallo.


A haplogroup is passed from father to son no matter how much the genetics change over the years. It is not passed down onto daughters either, so just looking at a haplogroup automatically makes you disqualify almost your entire ancestral line, since it ignores the mother, your mother's parents and your fathers mother and so on and so on. Finns share about an 80% mtDNA similarity to all Germanic peoples, and there is a reason: common ancestry. The Finns, like the Scandinavians, descend from stone age cultures like the boat-axe culture and the corded ware culture. Finns have the highest amount of northern hunter gatherer DNA (ancient people native to scandinavia and Finland) out of any people living today, as well as the highest amount of proto-indo-european ancestry. These ancient genetics also prove that Finns must not have really changed at all in the last couple of thousand years. So it is not inaccurate to say that Finns are in a way the most European people in Europe. Finns do have also ~3-5% of western Siberian ancestry as well, a relic of the people who brought the language over to Finland. However northern Europeans also have up to 4% neanderthal ancestry.

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