The limbs of vertebrate animals, including humans, evolved from fish fins.
Canadian biologists from the University of Montreal and the Institute of clinical research figured out why human hands are five fingers. It turned out that the development of the limb is determined by the specific placement of cells with active genes hoxa11 on the body of the embryo. Their findings are presented in the article.
Evolutionists believe that the limbs of vertebrate animals, including humans, evolved from fish fins. In August 2016 the researchers led by Professor Neil Shubin from the University of Chicago showed that for the formation of fin rays and fingers communicate with the same genes hoxa11 and hoxa13. However, it remained unclear how formed the palm of the person as lived in the water, the ancestors of the people had limbs, the number of rays in which more than five.
Scientists have found that the pattern of gene activity varies hoxa11 and hoxa13 in the limbs of fishes and land vertebrates. First, they function in the cells that overlap each other region. In humans, these genes work in separate areas of the rudiment of the limb. The researchers were able to reproduce in the nuclei of mouse hoxa11 activity that is typical for fish. As a result, animals have evolved to seven toes on one limb.
Genetics also found a DNA sequence that is responsible for the transition between different types of gene activity. This suggests that the change in the number of fingers was not due to the formation of new genes, but because of changes in the functioning of existing ones. The discovery confirms the view that the malformations of the embryo occur due to mutations not only in genes but in the regulatory sequences.
