The intersection of Neanderthals with early modern people may have given some malaria resistance
The intersection of Neanderthals and Denisovans with early modern people may be due to the resistance of some people to infectious diseases such as malaria
- Early people like Neanderthal and Denisovans bred with modern counterparts
- Modern people who live today have genes from these early hominins
- Some of these genes offer resistance to diseases and behavioral traits
Early hominins such as Neanderthals and Denisovans who breed with modern humans may have caused some people to have immunity to diseases such as malaria.
Researchers from the University of Bern in Switzerland also discovered that some personality traits, such as depression, were crossed between hominids.
Scientists have known about crossing between the species and the ability of genes to pass between them for some time – it is known as introgression.
Authors Alexandre Gouy and Laurent Excoffier from Bern created a computer model to study the pattern of early human-like genes in modern humans.
They discovered that those related to immunity may have been a major cause of “adaptive evolution” in modern people, making disease resistance and behavioral change possible.
Scroll down for video
Neanderthal Gay mature man, based on 40000 year old remains found at Spy in Belgium. National history museum. Researchers say that crossings between early people and early modern people have led to some immunity to diseases
“In general, our results suggest that archaic introgression has affected human metabolism and response to different types of pathogens, Dr. Said said. Excoffier.
In this study, the duo analyzed genetic data from various groups around the world, including people from Papua New Guinea who have malaria resistance.
“Our results not only show that introgression is found in many genes involved in the same functions, but also that some of these interacting genes carrying archaic DNA have been co-selected,” said Dr. Gouy.
They identified genes from other human species in each of the populations they studied, including East Asians, Europeans, and Papua New Guinea.
“One of the most striking indications of adaptive introgression is the potential resistance to malaria in Papua New Guinea,” said Dr. Excoffier.
A more controversial discovery area is the possible link between early human-like genes and the behavioral traits of modern people.
Their results are based on other studies that have identified Neanderthal genes that have previously been associated with behavioral traits such as depression, mood disorders and a tendency to smoke cigarettes.
“In Papuans, we have also found genes that exhibit a significant excess of introgression associated with autism sensitivity and attention deficit and hyperactivity disorder,” said Dr. Excoffier.
This is the reconstruction of a Denisovan girl. Scientists from Switzerland have studied modern human genes and have found a mix of Denisovan and Neanderthal genes
Their team also found other brain-biased genes in modern humans from early hominins in East Asian and European cultures.
“Further explorations of these areas of influence will be needed to tease their contributions to human health and disease,” he said.
“Although the total amount of Neanderthal and Denisovan introgression among modern people is quite low, their evidence continues to build the scientific proposition that the hominid DNA that remains has contributed to modern human adaptation.”
It also suggests that these human-like windows have a strong impact in the past and continue to influence the current fitness of modern people.
The findings are published in the journal Molecular biology and evolution.
WHEN DO PEOPLE HAVE FIRST FIRST?
The timeline of human evolution can be traced back millions of years. Experts estimate that the family tree as such goes:
55 million years ago – First primitive primates evolve
15 million years ago – Hominidae (great apes) evolve from the ancestors of the gibbon
7 million years ago – First gorillas evolve. Later chimp and human lines diverge
A recreation of a Neanderthal is shown
5.5 million years ago – Ardipithecus, sharing early ‘proto-human’ traits with chimpanzees and gorillas
4 million years ago – Monkey like early people, the Australopithecines appeared. They had brains no larger than those of a chimpanzee, but other, more human traits
3.9-2.9 million years ago – Australoipithecus afarensis lived in Africa.
2.7 million years ago – Paranthropus, lived in forests and had huge jaws to chew
2.6 million years ago – Hand axes become the first major technological innovation
2.3 million years ago – Homo habilis first thought to have appeared in Africa
1.85 million years ago – First ‘modern’ hand appears
1.8 million years ago – Homo ergaster begins to appear in fossils
800,000 years ago – Early people control fire and create fireplaces. The brain size is increasing rapidly
400,000 years agoO – Neanderthals appear for the first time and spread across Europe and Asia
300,000 to 200,000 years ago – Homo sapiens – modern people – appear in Africa
50,000 to 40,000 years ago – Modern people reach Europe