Life forms are evolving constantly, shedding away certain characteristics and holding onto – and in some cases picking up – others that ensure survival. It’s been happening since there was nothing but bacteria, and will continue until there’s no life whatsoever. Yet what makes modern evolution so fascinating is that in many instances, it’s occurring at an accelerated rate. Historically, evolution has been a more gradual process; humans, for example, took millions and millions of years to evolve from apes. Yet in recent years, rapid environmental changes have forced animals to adapt in just a few generations. While it doesn’t happen as quickly as it did with the alien bacteria in the movie “Evolution”, it’s happening so quickly that in many instances you can see it happening in real-time.
As humans push the environment to its limit, they’ve forced animals to evolve much faster than usual and rely on hidden gene variations, or genes that have long remained dormant. One example is the mosquito in the London Underground. When workers were building the tunnels that made up the London Underground some 150 years ago, mosquitoes were able to settle in, and evolved to the extent that they can no longer interbreed with above-ground mosquitoes. But animals much larger than mosquitoes have been evolving just as rapidly: a group of ten Italian wall lizards introduced to the island of Pod Mrcaru 40 years ago have since developed better bite strength, a larger head and a whole new digestive tract. And in Antarctica, climate change has led to blue and pygmy whales joining together to form a hybrid species.
Yet one of the most interesting, and striking, examples of modern evolution can be found in Africa, among elephants. As poachers target them for their ivory, they’ve evolved to eliminate their tusks. Not having tusks was previously a rare genetic mutation, and 50 years ago only about 10 percent of female elephants in Zambia were tusk-less. Yet as elephants with tusks are hunted almost to extinction for their ivory, that rare genetic mutation has begun to thrive, and tusk-less elephants are becoming more and more common.
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