Share the news of March 22 with wechat scanning QR code < / P > < p > to friends and circles of friends < / P > < p > < / P > < p > in people's habitual thinking, evolution usually occurs on the scale of millions of years. But a recent new study shows that biological evolution can also be fast, and some fruit fly genes can even change significantly with the seasons in a year < p > relevant research papers were published in the recent journal Science. Scientists have studied the evolution of about 10 generations of fruit flies, of which each generation takes only more than ten days. As we all know, the life span of fruit flies is very short, and the time interval between generations is very short. But Seth Rudman, an assistant professor at the school of Biological Sciences at Washington State University and one of the authors of the related paper, believes that even organisms with longer lifespans may evolve faster than previously expected < / P > < p > "in the past few decades, people have increasingly realized that evolution can happen quite quickly," Rudman said < p > in this new study, the research team placed 1000 fruit flies in 10 outdoor areas. Each area is carefully woven with nets and planted with small trees to help fruit flies rebuild a Habitat similar to the wild. Over a period of four months, the researchers allowed fruit flies to move freely in each closed area and fed each group the same food. The experimental environment "allows researchers to track multiple Drosophila populations and see how their genes and characteristics respond to the same abiotic and biological factors over time." < p > during the whole experiment, about 10 generations of Drosophila melanogaster were produced, and the population was growing rapidly. At the peak of the experiment, there were up to 100000 fruit flies in a closed area < p > the research team will regularly inspect fruit flies to understand how the genes and characteristics of these insects change over time. The researchers analyzed and compared experimental characteristics such as reproductive success rate and heat and cold tolerance. In order to ensure that these characteristic changes are caused by genetic changes, the researchers will take 2500 Drosophila eggs from each closed area, feed three generations of new populations respectively, and then compare them to ensure that these genetic changes persist < p > at each examination, the research team randomly selected 100 fruit flies from each closed area and sequenced their whole genome. In this way, the researchers can obtain the changes of allele frequency at different positions of 100 tested fruit flies over time < p > in four months, researchers found that more than 60% of the Drosophila genome had direct or indirect changes. Rudman called it "amazing". The researchers explained that evolutionary selection caused by seasonal changes such as summer and autumn directly affects a small number of genes, while some DNA changes in the process of "genetic implicature effect" affect another part of DNA < p > researchers found that most of these genetic changes are adaptive, not just genetic drift. They came to this conclusion because these genetic changes occurred in Drosophila populations in most experimental areas, not in individual cases < p > according to Rudman, the speed of all these genetic changes is unexpected, indicating that these fruit flies have a faster evolutionary time and adapt to the environment than previously measured < p > the study also found that the direction of Drosophila evolution has changed many times, and the genetic changes swing back and forth like a pendulum with environmental conditions. "It's very surprising that you'll see a feature evolve in this direction in a few weeks and then reverse next month," Rudman said. "This is a real dynamic adaptation and natural selection scenario. The direction of natural selection is changing, the goal is changing, and it's changing very quickly." < p > Rudman said that although Drosophila flies live a short life and reproduce quickly, other species may evolve and adapt to the environment faster than originally thought. However, he added that it is too difficult to study the evolution of long-lived organisms. However, "evolution can happen very, very quickly," Rudman stressed. (Chen Chen) < / P > < p >