The Genetic Map of Humans PART 1

Where we came from through DNA mapping!

The first modern humans to leave Africa about 80,000 years ago encountered Neanderthal settlements in the Middle East and, on at least some occasions, chose to make love instead of war, according to an international team of scientists who have pieced together the genetic code of humanity’s closest relatives. The ancestors of modern humans and Neanderthals lived about 600,000 years ago in Africa. The Neanderthal lineage left the continent; the fossils of what we describe as Neanderthals range from 200,000 years to 40,000 years in age, and are found in Europe, the Near East and Siberia. The species that you and all other living human beings on this planet belong to is Homo sapiens. During a time of dramatic climate change 300,000 years ago, Homo sapiens sapiens evolved in Sub Saharan Africa and they were dark skinned melanated people. All modern humans come from these people!

Scientists believe that the earliest migrations out of Africa occurred because of a climate change that helped to push them out. Experts suggest that droughts in Africa led to starvation, and archaic humans were driven to near extinction before they ever had a chance to explore the world. A climate shift and greening in the Middle East probably helped to draw the first humans out of Africa. Once this ancestral population had split, the sub Saharan branch of the human family tree stayed in Africa during a time of extreme dramatic climate change 300,000 years ago, and evolved into homo sapiens sapiens while the Neanderthal/Denisovan one moved into Eurasia. By roughly 430,000 years ago, the Eurasian branch had itself split, ultimately giving rise to the Neanderthals in western Eurasia and the Denisovans in the east. Homo sapiens that evolved in Africa like other early humans that were living at this time gathered and hunted food, and evolved behaviors that helped them respond to the challenges of survival in unstable environments.

These humans developed advanced linguistic abilities the way Homo Sapiens used language affected their ability to hunt, trade, and dominate the animal kingdom. Denisovans are close relatives of both modern humans and Neanderthals, and likely diverged from these lineages around in the Eurasian steppes 300,000 to 400,000 years ago; they are more closely related to Neanderthals than to modern humans. Denisovans ranged from Siberia to Southeast Asia and may have persisted until as recently as 30,000 years ago, based on their genetic legacy in living Asians. Present-day individuals in East Asia carry the highest percentages of genetic ancestry from Denisovans, in mainland Asia the amount of Denisovan ancestry in present-day populations is less than the East Asian amount of Neanderthal ancestry by a factor of 10.People in China, Japan and other East Asian countries have about 20 percent more Neanderthal DNA than do Europeans. Studies of Chinese populations show that 97.4% of their genetic make-up is from ancestral modern humans from Sub Saharan Africa, with the rest coming from extinct forms such as Neanderthals and Denisovans.

Two distinct interbreeding events with Denisovans, a sister group to Neanderthals, contributed to the ancestry of modern East Asians, according to a genetic data analysis. Genetic evidence shows that the Philippine indigenous Negrito ethnic group inherited the most Denisovan ancestry, the lighter complexion Philippine have more Neanderthal ancestry. Indigenous people known as Ayta Magbukon get around 5 percent of their DNA from Denisovans. Roughly two percent of the genomes of Europeans and Asians are Neanderthal. Asians also carry additional Denisovan DNA. The percentage of Neanderthal DNA in modern humans is zero or close to zero in people from Sub Saharan African populations, and is about 1 to 6 percent in people of European or Asian background. Contemporary Europeans have as many as three times more Neanderthal variants in genes involved in lipid catabolism than Asians and Africans. Genetically, Native Americans are most closely related to East Asians and Ancient North Eurasian.

Native American genomes contain genetic signals from Western Eurasia due in part to their descent from a common Siberian population during the Upper Paleolithic period. DNA from 49 new samples from Central and South America dating from 10,900 to 700 years old, at more than 1.2 million positions across the genome. All told, the data does not decisively dispel suggestions that early populations had a different ancestry from today's Native Americans but lends credence to the theory there were multiple periods of human arrivals from different global starting points. "Native Americans truly are indigenous to the Americas, Just as Europeans are indigenous to Europe as the first peoples to inhabit the continent. They are a genetically and culturally distinctive group but they did not appear out of thin air and even as the Chinese failed to prove they suddenly appeared on the planet the Natives of the Americas must accept their ancestry goes back to Africa as all mankind despite popular propaganda to the contrary this is the truth. There are Denisovan genes in Native Americans, providing new evidence that some of the ancestors of the Native Americans migrated from Asia.

The microsatellite diversity and distributions of the Y lineage specific to South America indicates that certain Indigenous American populations have been isolated since the initial peopling of the region. We used the two high-coverage archaic genomes and a hidden Markov model (HMM) to identify regions of specifically Neanderthal and specifically Denisovan ancestry in 13 experimentally phased present-day human genomes (Supplementary Information sections 4 and 13). In the Sardinian and French genomes from Europe we find genomic regions of Neanderthal origin and few or no regions of Denisovan origin.

In contrast, in the Han Chinese, the Dai in southern China, and the Karitiana and Mixe in the Americas, we find, in addition to regions of Neanderthal origin, regions that are consistent with being of Denisovan origin (Z Score 54.3 excess relative to the Europeans) (Supplementary Information section 13), in agreement with previous analysis based on low-coverage archaic genomes. These regions are also more closely related to the Denisova genome than the few regions identified in Europeans (Supplementary Information section 13). We estimate that the Denisovan contribution to mainland Asian and Native American populations is 0.2% and thus about 25 times smaller than the Denisovan contribution to populations in Papua New Guinea and Australia.

The fascinating part of this, aside from the fact that Native people also carry both Denisovan and Neanderthal DNA, and that they carry more than Europeans, is that the Denisovan and Neanderthal DNA that they carry is different from that carried by Europeans.

The fascinating part of this, aside from the fact that Native people also carry both Denisovan and Neanderthal DNA, and that they carry more than Europeans, is that the Denisovan and Neanderthal DNA that they carry is different from that carried by Europeans.

“The risk haplotype carries four amino acid substitutions, all in SLC16A11; it is present at ~50% frequency in Native American samples and ~10% in east Asian, but is rare in European and African samples. Analysis of an archaic genome sequence indicated that the risk haplotype introgressed into modern humans via admixture with Neanderthals.”

“Researchers determine the degree to which a mutant gene differs from the most common sequence (wild type), then impose a time scale in the form of known mutation rates. The SLC16A11 five-site haplotype is so divergent that it goes back to nearly 800,000 years ago — before modern humans evolved and expanded out of Africa.

The most plausible explanation, seemed to be that the haplotype came from an archaic(old/ancient) human – a Neanderthal or Denisovan or their as-yet unnamed contemporaries. And the haplotype indeed shows up in the skeleton of a Neanderthal found in the Denisovan cave in Siberia.”

And so, it seems this is more proof that the Native American people today indeed inherited their propensity for type 2 diabetes from their ancient Neanderthal ancestors who lived in the Altai Mountains. It also appears that this genetic predisposition did not carry forward to Europe, indeed it is possible this group of Neanderthals was not ancestral to Europeans at all. Several times in history, genetic studies show, Native Americans returned across the Bering Strait to Eurasia—long before Europeans began arriving in distant parts of the Americas.