Ancient DNA from last Ice Age unveils distant ancestors underwent significant evolutionary changes

The DNA analysis was carried out from the ancient bones, 45,000 to 7,000 years old, of 51 of the prehistoric humans. The evaluation has found that all Europeans had descended from early humans living somewhere in Belgium.

Another important thing is our distant ancestors have been undergone massive evolutionary changes in the Ice Age period and a few thousand years following that era. Around 19,000 years back, the temperature started to increase in Europe, making the continent warm.

As the frozen cover declined, human populations from modern-day Spain started migrating towards the north. Around 5,000 years after that time period, another group of people started to travel from southeastern Europe into northern and western regions of the continent. This population displaced the earlier population.

The last major ice age peaked between 35,000 and 19,000 years back, before coming to an end around 12,000 years ago. “The ability to obtain genome-scale data from ancient bones is a new technology that’s only been around for the last five or six years. It’s a new scientific instrument that makes it possible to look at things that have not been looked at before”, said David Reich of the Harvard Medical School.

The researchers have also found that the percentage of Neanderthal DNA in Europeans 45,000 years ago has declined from between 3% and 6% to around 2% in Europeans today. The researchers think that natural selection has reduced Neanderthal ancestry over time.

Dr. Reich even mentioned that Neanderthal DNA is slightly toxic to modern humans. Earlier, the available data was limited, but with 51 samples, everything has changed. Dr. Reich said that they were able to have an idea of dynamic changes that have taken place over time.

“The genetic data show that beginning 37,000 years ago, all Europeans come from a single founding population that persisted through the Ice Age, said, Reich. The founding population has some deep branches in different parts of Europe, one of which is represented by a specimen from Belgium. This branch seems to have been displaced in most parts of Europe 33,000 years ago, but around 19,000 years ago, a population related to it re-expanded across Europe, Reich explained. Based on the earliest sample in which this ancestry is observed, it is plausible that this population expanded from the southwest, present-day Spain, after the Ice Age peaked,” according to a news report published by Phys.

The second event that the researchers detected happened 14,000 years ago. “We see a new population turnover in Europe, and this time it seems to be from the east, not the west,” said Reich. “We see very different genetics spreading across Europe that displaces the people from the southwest who were there before. These people persisted for many thousands of years until the arrival of farming.”

According to a report in Tech Times by James Maynard, “Ancient DNA left over from the last ice age shows that all Europeans, at one time, were descended from early humans living in Belgium. Analysis of genomes also suggested our distant ancestors underwent significant evolutionary changes during the Ice Age and a few thousand years following that frigid era.”

“The ability to obtain genome-scale data from ancient bones is a new technology that’s only been around for the last five or six years. It’s a new scientific instrument that makes it possible to look at things that have not been looked at before,” said David Reich of the Harvard Medical School.

A report published in CS Monitor informed, “Then, in a second major population shift that coincides with a warming climate after the Ice Age, about 14,000 years ago, populations from places such as today’s Turkey and Greece spread north and west into Europe, displacing the first group.”

“What we see is a population history that is no less complicated than that in the last 7,000 years,” said David Reich, a paper co-author and geneticist from Harvard Medical School, “with multiple episodes of population replacement and immigration on a vast and dramatic scale, at a time when the climate was changing dramatically.”

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