Elephant Evolution

Thursday, October 12, 2017

Elephant Evolution

The order under which Elephants are classified is the Proboscidea. This is for one of the elephant’s most interesting physical features. It is something that attracts curiosity from around the world for elephants along with many other aspects in the past only ascribed to the human, such as, rudimentary tool use, complex social behaviors, and reverence for a dead family member or friend. It is their trunk or proboscis; the meaning of Proboscidea species is simply animals with trunks/proboscis.

Henry F. Osborn identified some 352 proboscidean species and subspecies of which only half are recognized and valid today. About 50-60 million years ago, the ancestors of the modern elephant occupied a variety of extreme environments; this includes from tropical rain forests to deserts in both low and high altitudes. Incredibly, with the exception of Australia and Antarctica, the proboscideans have over time inhabited every single continent on Earth. Why did all but two become extinct? One possible explanation for their disappearance may be found in the inability of the order to evolve to environmental change fast enough. One of the determining factors in this is the more specialized a particular genus of animals, then the more likely they they will become extinct in periods of dramatic climate and environmental change. Both of the surviving African and Asian elephants have a wide range of attributes which give them the ability to survive and to even thrive in mild to extreme environmental conditions. Obviously, this is probably not the only reason for the disappearance of  most of the order, but serves as a good generalization for a reason why the multiple families of the order disappeared over time.

Another surprise to many is to find that elephants have some relationship to manatees which are commonly referred to a sea cows. It is believed that early on many species of elephants had two sets of tusks – one in the upper jaw and one in the lower jaw. What is very sad is that many experts believe at one time there were more than 350 species of elephants in the world. Now there are almost none at all left.

Early elephants were very different in their size and their appearance back then compared to what we see of them today. During the Ice Age the elephants likely had very thick hair like the mammoth. However, as the temperatures got warmer they didn’t have a need for it. This is why they got thicker skin and very little hair on it at all. This allowed the to live in regions where the temperatures were extremely hot. They have to be able to reduce their body temperatures and to regulate them. This can also account for the larger size of the ears; they use them as fans to cool down.

The length of the trunk as well as the ability to use it for so many different things is also something that happened for elephants through evolution. Their needs to be able to grasp things are one of the main reasons why this likely. While early elephants did have trunks they weren’t as versatile as what these animals have today.

It is believed that the ability adapt to a variety of different environments allowed elephants to evolve about 50 to 60 million years ago. Some of them lived in the rainforests while others resided in the desert. They are still considered to be on of the most adaptable animals in the world. However, with humans taking these areas away from them at an alarming rate there is a limit to what they are able to do and where they are able to survive today.

What has been noted by experts it that this evolution process takes place very slowly. This is why so many other species of elephants weren’t able to survive those necessary changes and they are no longer with us today. With that in mind humans have to understand that we can’t simple continue to do what we want to and expect that elephants are going to be able to change fast enough to adapt to all of it.

As you can see the evolution for elephants is one that is quite amazing. Even though we know quite a bit about these animals and their past, many questions still have to be answered. They have continually fought though for survival and due to the evolution process they have been quite successful for millions of years.

References

Michael Garstang. Elephant Sense and Sensibility. Academic Press, 2015.

Raman Sukumar. The Living Elephants: Evolutionary Ecology, Behaviour, and Conservation. Oxford University Press, 2003.

http://www.ucmp.berkeley.edu/mammal/mesaxonia/elephantidae.php

http://www.birds.cornell.edu/brp/elephant/cyclotis/evolution.html

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