The human ancestors lived about 239,000 years ago?

By identifying the DNA sequence of 2636 inhabitants in Iceland, scientists have identified the role of gene mutations for all diseases that modern humans may have. At the same time, the study led to a surprising conclusion: Y-chromosomal Adam - " Human ancestor" lived about 174,000 to 321,000 years ago. The results of the study were published in the recent issue of Nature Genetics.

New discovery about human ancestors

This is a study based on the database of genes taken from the largest number of people in the same population. The co-author of the study, neuroscience professor Kari Stefansson said: "What we have achieved allows for a more detailed view of a nation's genome sequence. This is a big step forward. with our understanding of the correlation between abundance in DNA sequences and human diversity. "

According to anthropology, Mitochondrial Eve and Y-chromosomal Adam (MRCA and Y-MRCA) are two individuals who have passed on the genome to all humans today . In other words, this is the ancestor of humanity. Previously, many studies were conducted to estimate the ages of these two individuals. However, most research results are based on unreliable databases and lead to conflicting conclusions. A study conducted in 2013 by the University of Arizona, the United States estimated that the age of the " human father " was about 340,000 years old.

Illustrations

However, this study is based on Icelandic residents who believe that " Adam " has a younger age. Accordingly, he lived about 239,000 years ago. This figure is close to the number of Eve's ages identified in a recent study of 200,000 years old. Agnar Helgason, an anthropologist at the University of Iceland, co-authored the study, said: "People are always curious about where we come from and how to come. This research has provided more information to answer to the question when ". From an evolutionary point of view, species that live longer will have more time to develop mutations to differentiate individuals, gradually forming separate populations. If we can determine the age of humanity, we can understand the origin of human diversity.

Also in this study, the scientists analyzed 8000 Icelanders with at least one gene completely submerged. Results showed that the human olfactory gene has the highest rate of diving among the 1171 recessive genes. Helgason said: "From here, we have more insight into human recessive genes. Can this answer the question of how many people encounter all recessive genes? this rate for Icelanders is about 7.7%. "

Although this study has a large database compared to previous studies, some industry experts believe that it has not been designed perfectly. Duke University researcher Andrew Allen, who did not participate in the study, said: "This study only synthesized previous databases so the sample may be inaccurate, shadowed and not. can be used to deduce the characteristics of the actual population. "

In addition, Allen said: "Iceland is a population complex that has historically been quite unusual. The country is relatively isolated and has a population of only 320,000. Their ancestors are less likely to be exposed. with the outside world as it is now, this has made it difficult to draw conclusions about the human gene selection process in history . " Professor Stefansson argues: "The Icelandic people show no signs of hybridization. Therefore, the 7.7% figure is almost universally applicable to other peoples."

However, it is thought that the research is still useful for reference, providing information about the activity of recessive genes . Other researchers can use research results to determine the relationship between genetic traits and human morbidity, thereby suggesting more effective methods of diagnosis and treatment. As for the " age of Adam and Eve" puzzle, researchers still have to continue to make more statistics with larger sample sizes, to ensure the reliability and accuracy of the conclusion.