In cities, the evolution of plants and animals is going in strange ways. Changes can be furiously fast

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During World War II, Londoners fled to hide in subway tunnels, bloodthirsty mosquitoes waiting for them. They stung like angry. These were mosquitoes of the species that commonly live in London parks and attack birds preferentially. Although mosquitoes found safe shelter from natural enemies in the metro area, the birds were missing for understandable reasons. But there were plenty of rats.

And so the mosquitoes retrained as mammalian blood drinkers. People looking for shelter from German bombs in the subway were a great feast for them. This earned underground mosquitoes a zoological designation Culex pipiens molestus that is, a mosquito difficult. The London mosquitoes, adapted to the subway tunnels, were one of the first revealed examples of evolution that took a whole new direction in the city.

We often imagine evolution as a process whose results are not visible until millennia ago. But this is a mistake. Evolution can pick up a frantic pace. For example, a recent study showed that octomiles change hereditary information from generation to generation so quickly that it allows them to adapt to different seasons. Sure, it records a rapid multiplication, but even so, we are witnessing significant evolutionary changes within generations, which we would count on the fingers of both hands.

Not all creatures can cope with the demands of city life. One of the conditions is the relatively large variability of behavior, which today scientists often do not hesitate to call a personality. In an urban environment, creatures that are more fearless and resistant to stress usually prevail. For example, the little owl in the 300,000-strong Argentinian city of Bahía Blanca managed it.

The tiny owl, about twenty centimeters tall, is conspicuous by its long legs. They are useful for her when hunting insects and other small animals, which she does not chase from the air, but chases after them on the ground. The little owl also differs from most of its relatives in that it prefers prey at dusk or dawn to night hunting.

The owl got its name from the fact that it nests in the abandoned burrows of smaller mammals. This is an absolute exception among owls. Urban owl populations are thriving in Argentine cities. If in the Argentine countryside their nests are usually about fifteen kilometers apart, it is no exception in the city when two nests are only ten meters apart.

Cooper’s Hawks are similarly successful in the American urban environment. They are attracted by a large population of pigeons. They are doing great. Maybe too much, because the new Mexican Albuquerque, for example, is already crowded with hawks. Many young predators are forced to leave their hometown and find a place to live on its outskirts.

There is thirty birds per hawk that moves into the city, which gives the city its ramparts. It might seem that the birds raised in the city will be outsiders in a rural environment. But the exact opposite is true. Urban outcasts often push rural natives out of their nests.

Urban blackbirds use street lighting to extend the time they can forage, and they also use courtship on a day stretched by hours of artificial lighting. They have a hereditary internal biological clock adapted for this. In the hereditary information of urban blackbirds, researchers have identified several gene variants that are beneficial to urban life, and evolution clearly favors them in urban birds.



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