The genes of mice are highly similar to those of humans. Why is the gap between the two so big?

Some scientists have shown that almost 80% of the genetic materials of mice and humans are the same, and the genetic composition of mice is 90% similar to that of humans. Therefore, scientists often like to do experiments with mice when conducting biological experiments. But we have to wonder, since the genetic composition of mice is so similar to that of humans, why is there such a big gap between the appearance of mice and humans?

The reason why the genes of mice are highly similar to those of humans is that humans and mice have the same ancestor hundreds of millions of years ago, but we must understand that the high similarity of genes does not mean that they will look almost the same. In fact, it's not just mice that are highly similar to human genes. There are many other mammals with high genetic similarity to humans, but most of them are also very different from humans. For example, chimpanzees are 96% genetically similar to humans. We need to understand that the similarity of genes does not mean that the genes are exactly the same. Even if there is a difference of 10%, their characters will be completely different, which means that similar genes only determine the general structure of organisms.

Besides, the difference in appearance between mice and people is so great because of the different living environments. Although mice and humans may have a common ancestor, mice and humans chose different living environments in their later evolution. In the process of continuous evolution, environmental factors have led to the constant differences in their appearance. We all know that the genetic material of living things is DNA, which can be transcribed and translated into RNA. However, not all genes in a species can be transcribed and translated, and the gene expression of different species should adapt to the environment, so even if the gene similarity is as high as 90%, the appearance of mice and humans will be different.

In short, gene similarity does not mean that genes are the same, so human beings and mice will grow so big through the regulation of various factors.