Fish began to evolve faster. What is the reason?

Recently, fishermen, and then scientistsnoticed that some species of fish began to reach puberty much faster than before. At the same time, the average size of individuals decreased significantly. Initially, this was not given special significance, but recent research shows that such changes may be associated with evolutionary processes. And scientists were able to identify the mechanisms that affected it.

Why did fish begin to evolve?

According to the editors of Science Daily,in fact, everything is quite banal: over the past few decades, fishing for commercial fish species has increased significantly, and this has led to the fact that the marine inhabitants had to somehow adapt themselves to such “planned destruction”.

Most people think of evolution asvery slow process that takes place over several millennia. But evolution can, in fact, happen very quickly. - says the lead author of the study, a professor at Cornish University Nina Overgaard-Terkildsen. Slow-growing fish will better avoid nets, thus having higher chances to pass on their genes to next generations. Thus, fishing can lead to rapid evolutionary changes and the development of new properties in fish. We see many signs of this effect on the example of wild fish.

As scientists realized that fish began to evolve

Experts from the University of Cornwallanalyzed data from an experiment conducted back in 2002. Six populations of Menidia menidia (found in Western Atlanitka), small commercial fish, the average length of which is about 15 centimeters, were selected in laboratory conditions. The largest individuals were removed in two populations, and the smallest individuals were removed in the other two. In addition, a control group was also present, where several fish of different sizes were randomly selected.

See also: What is the smallest shark in the world?

This selection lasted for 4 generations.and as a result, in the last generation, the length of the body of fish in the first group decreased on average by about half. But it was known more than 15 years ago. Now scientists, using fish samples, completely sequenced the genome (that is, in simple words, “laid it out into its constituent parts”) of almost 900 individuals and revealed huge changes in the composition of DNA. The team found about 200 changes across the genome, which were sequentially changed between populations. They also found sections of DNA that "turned off" the ability of marine animals to grow. Moreover, the more fish populations there were, the more clearly the changes could be traced.

New research, according to scientists, will helpassess the impact of man on wildlife and understand how to deal with the consequences that cause the animals around us to change. After all, a change in some species will invariably entail a change in others, and this can harm the entire world ecology.

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