From ancient times to the present, has human beings themselves been evolving?

As we all know, technology has been constantly improving over time. As the current masters of the earth, have we evolved? If so, how have we evolved compared to people 5,000 years ago?

5,000 years ago, probably at the end of the Neolithic Age, there is clear evidence of evolution compared to now, including but not limited to the following points. Let's talk about the obvious evolution of human beings in the long river of history.

01. Mitochondrial evolution after humans left Africa

Simply put, during these 100,000 years, we humans have continued to move around the world, and in the process, our mitochondrial mtDNA has also mutated and faithfully recorded each group.

At present, it can be divided into two major branches, M and N. The N branch includes all the haplotype groups specific to Western Eurasia (H, I, J, K, T, U, etc.), the haplotype groups specific to East Asia (A, B, R9, N9, etc.) and the P haplotype group specific to Oceania. The lineages downstream of the M branch are distributed in populations in East Africa (M1), South Asia (M1-M6), Oceania (Q/M12) and East Asia (C, D, G, M7, M8, M9, etc.). Generally speaking, it is a classification diagram like this:

02. Evolution of the skin color gene OCA2

A mutation at a site on this gene (rs1800414, His615Arg) causes the skin color of East Asians to be white due to the founder effect (founder effect, founder effect_Baidu Encyclopedia). The evolutionary scale appeared 10,000 years ago and was further purified.

ps: The founder effect is commonly explained as ancestors will determine their descendants. For example, if your ancestor is of the yellow race, due to geographical reproductive isolation, in the end, his descendants will basically be of the yellow race (of course within a certain period of time)

Figure: Distribution of skin color mutant genes around the world (dark blue = black, yellow = white)

03. Energy intake (APOE, etc.)

This gene is apolipoprotein, and the above genotyping is a recent evolutionary event. APOE is divided into three types: 2, 3, and 4. Due to the huge changes in human eating habits, especially the recent changes in food structure, the proportions of these three types have also changed.

Type 3 is the middle type, with an increase of about 70%, Type 2 is the beneficial type, which can take in a small amount of fat, with an increase of about 15%, and Type 4 is the harmful type, with an increase of about 15%. The changes in these three groups are very obvious. Among them, the proportion of people with Alzheimer's disease in Type 4 is more than 4 times higher than that of Type 2.

04. Body odor ABCC11 gene

This is a typical genetic drift. Body odor is partly determined by the ABCC11 gene in the middle of chromosome 16. During the process of human evolution, the ancestors of East Asians happened to mutate at base 538 of this gene . Moreover, because the group was small enough during that period, this site was homozygous, and they did not have genetic exchange with other sites with this mutation (bang bang bang), so in the end it became more and more pure. Now, body odor is a minority phenomenon in East Asia.

Figure: Distribution of mutant genes that remove body odor around the world (black = body odor type, white = mutant type)

05. Other possible evolutionary processes include

Of course, there are other possible evolutionary processes, including:

1. Degeneration of wisdom teeth - changes in eating patterns. About 30% of people no longer have wisdom teeth.

2. The reduction of body hair is mainly due to the process of human using bark-fiber and silk-cotton-chemical fiber.

3. Degeneration of the coccyx - you can tell by touching it yourself

4. Degeneration of the Y chromosome - please refer to my other answer "Have humans stopped evolving? - Answer from a Zhihu user"

5. Evolution of disease-resistant genes - This is mainly due to the occurrence of large-scale epidemics, such as the famous Black Death, which served as an objective screening process.

06. Let’s talk about evolution

First, evolution is not necessarily good . There is no right or wrong in evolution itself. It is just that some unfitted species are eliminated. So, don’t think that evolution is a good thing.

Second, the scale of evolution is very broad . Generally speaking, the evolution of a gene is on the scale of more than a million years. In other words, if you want to inactivate a gene or add a new gene, it will take at least hundreds of thousands of years.

Third, evolution does not happen overnight . If you take too big a step, you will fail. For example, the skin color gene OCA2 mentioned above is 340,000 words long. At present, a mutation has led to a huge differentiation of skin color, which takes about 10,000 years. Therefore, if you want to change this gene completely, it will take a long time. Of course, not all sites on the gene are equally important. Exons, especially the coding region, are the most important because they encode proteins and are difficult to mutate, while introns are easy to mutate.

Finally, the above are just very obvious traces. In fact, the fact that you have different genes from your parents is a kind of evolution in itself. It's just that this evolution is too small.