Extinction through time; were humans a factor in the past, too?

By Gloria Lima

It’s known that humans have played a large role in the extinction of many organisms. But does this mean we are the only cause? How is it possible for us to tell if we are the only factor or if we simply play a large role in the whole ordeal? Paleoecology offers clues, starting with which organisms went extinct, and which survived. We can look to paleontological data for patterns, like the body size of extinct species, or how those species interacted with their habitats.  By comparing fossil and modern animals, it is then possible to see how the organisms in the past interacted with their environments, by looking at the ecology of their surviving relatives.

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Image courtesy of Smithsonian Magazine.

Much of what we know about extinction comes from carbon dating the remains of extinct animals. An example is seen in the article “Patterns of generic extinction in the fossil record.” The authors looked at many fossils from a wide range of genera to see if there was a common pattern in extinction among the organisms. If there was a trend, it’s then possible to see whether the environment played a large role in the extinction, compared to the biology of the organisms. If so, this could mean that the climate caused a change in the environment before the organisms were able to adapt to it. Continue reading