Animals Are Evolving Faster Than You Think And There Is Proof
Biological evolution, the changes in living organisms over time, is often considered an elusive and long process that cannot be observed during a human lifespan. But is that really the case? And is there evidence that we can see it happening right before our eyes?
Evolution is a process that occurs at a different pace in different organisms. For instance, paleontologists have shown, thanks to the fossil record, that it took a million years for whales to evolve from their land-dwelling mammalian ancestors.
But evolution can also be observed and monitored in living organisms within a human lifetime. This is true for infectious agents, such as bacteria and parasites, that can evolve extremely quickly to resist the drugs we use to fight them. But it is also the case for larger organisms, such as vertebrates – the back-boned animals.
Times they are a changin’
One of the most famous examples was documented in a population of finches living on Daphne Major island in the Galapagos archipelago. In this case, ground finches Geospiza fortis evolved larger beaks after a major drought in 1977. During this harsh period, the small seeds on which the ground finches were feeding on became scarcer, and most of the birds died.
However, scientists noticed that the mortality rate was lower among larger birds, with a larger beak. They were able to crush bigger and harder seeds to feed on while the small seeds were depleted. Large-beaked finches had a great advantage over their small-beaked relatives to survive these tough conditions. They reproduced more and transmitted this trait to their offspring. Following the drought, scientists observed a shift towards larger beaks and body size among subsequent generations.