Who pushes evolution forward?

More and more evidence is showing that humans are now the main driver of evolution on Earth. From reproduction to environmental change, we are changing the planet so much that we are now determining the direction of life. Climate, which determines how living organisms evolve, recedes into the background.

The study used white clover (Trifolium repens), a plant native to Europe and Western Asia but found in cities around the world, as a model. After collecting more than 110,000 samples from large areas around the world, ranging from cities to suburbs and rural areas, they found: Clovers in cities now look more like clovers in another city thirty-nine countries away than clover grown in nearby farmland or forests.whatever the climate.

White clover (Trifolium repens) / Unsplash photo

This is an example of parallel adaptive evolution, where separate populations form under the same selective pressure for certain traits in different places. This suggests that the ways humans change the environment have a greater impact on the formation of these traits than local population genetics and natural phenomena such as climate. Although urbanization seems to have many common features around the world, it has not yet been determined that they act together and push evolution in the same direction. Now scientists have shown that this happens on a global scale, often in similar ways.

For urbanization to promote parallel evolution, urban areas must overlap in ecological characteristics that affect the fitness of the organism.
– the researchers explain in their work.

On closer inspection, the international team found that one feature that varies from town to village is the factories’ production of hydrogen cyanide. White clover uses this chemical as a defense mechanism against herbivorous predators. It also helps it withstand drought. Factories in the most remote rural areas were 44 percent more likely to produce hydrogen cyanide than factories in urban centres. Grazing appears to produce more hydrogen cyanide in rural areas than in cities where grazing pressure is less severe. In the absence of this pressure, drought becomes the driving factor.

Humans have already disrupted the natural size range of animals in the ocean., partly by preying on and selectively eliminating large fish, leaving more individuals with small fish genes to create subsequent generations. Many fish are now 20 percent smaller and their life cycles are on average 25 percent shorter. unpredictable the consequences of our actions also change the shape of the birds.

The wingspan of cliff-dwelling swallows became shorter near roads, and the wingspan of swallows killed on the road became longer, consistent with the increased choice of maneuverability in traffic conditions.
– In 2018, announced zoologist Sarah Otto.

These recent studies are another example of a clear sign of urbanization in evolution. Research shows that rates of evolutionary change in urbanized landscapes are higher than in natural and unurbanized human systems. “This is the most convincing evidence that we are changing the evolution of life on Earth. [містах]. It will be important to society as well as to ecologists and evolutionary biologists.”, UTM biologist Rob Ness. In particular, the amount of urbanized land is expected to triple by 2030 compared to 2000.

The researchers have now amassed a large database that they can work with to further investigate the human impact on alfalfa evolution. By better understanding how we accidentally cause such changes, we have a better chance of consciously taking the reins and guiding evolution in a more informed and confident way.

This knowledge can help protect some of the world’s most vulnerable species, reduce the impact of pests, improve human well-being, and contribute to an understanding of key eco-evolutionary processes.