On August 1st, a Cornell University research team published a study in the journal Science revealing genetic changes in fish that are rapidly evolving due to overfishing.
Nina Ovgard Selkerson, a professor of protective genomics at Cornell University, said: "Evolution is generally considered to be a very slow process that takes thousands of years to over-develop, but in fact, evolution can be very rapid Occurs."
“In the large-scale mined fish, the larger fish are often caught. The slower-growing fish will be smaller and better escape the fishing net, thus giving them a higher chance to pass on their genes to the next generation. Come fishing, which leads to rapid evolutionary changes in growth rates and other characteristics. We see many signs of this effect in wild fish populations, but no one knows what the underlying genetic changes are."
Selkelsen and her colleagues used a very meaningful experiment published in 2002. Six Atlantic silverfish populations (a fish no longer than 15 cm in length) were heavily fished in the laboratory. Among the two populations, the largest size fish were removed; of the other two populations, the smallest size fish were removed; in the last two populations, fishing was random.
Studies have shown that these Western silverfish have only passed four generations, and fishing has resulted in almost twice the size of adult fish between groups. Selkerson and her team sequenced nearly 900 whole genomes of these fish to test for changes in DNA levels that caused these dramatic changes.
The team identified hundreds of different genes in the genome that are constantly changing in populations that choose to grow rapidly and slowly. They also observed a large number of genetic linkages that synergistically changed, while dramatically changing the frequency of hundreds of genes.
Surprisingly, the researchers also found that these huge changes only occurred in some fish. This means that in this experiment, fish have multiple genomic solutions that either grow larger or smaller.
Selkerson pointed out that such research can assess human influence and improve the understanding of the speed, consequences and reversibility of human adaptation to complex environments.