Monday, 14 March 2011

Evolution of the Elephant

Hello we are Aroa and Pedro and here we left our project about existence and evolution of elephants through history of life, we left some photos too so you can see changes on this animals in different phases of their evolution.

Evolution of the Elephant
Elephants are the biggest terrestrial animal that still existing nowadays. They are a thick skin mammal’s family. They are born with a weight of one hundred and twenty kilograms and they reach heights of three point ninety six meters. Actually there are three main populations of elephants:
  • Asian Elephants (Elephas)- Inside this group we know that there are several subspecies thanks to the fossil register.

    - Elephas Maximus.

    - Elephas antiquus. This one is already extinct.

    - Elephas beyeri- This one is already extinct.

    - Elephas falconeri- This one is already extinct.

    - Elephas recki- This one is already extinct.

  • The Borneo elephant-This group is a definitive subspecies of the Elephas maximus borneensis.

This present different groups of elephants show us that as all living being in the planet had change through history of life, showing us that evolution is a fact. All this species came from the same ancestor, the Moeritherium, a pig-like animal that lived about 37-35 million years ago. They were smaller than modern elephants and their teeth suggest us they ate water vegetation. Even this is elephant’s ancestor it is not the real modern elephants ancestor it is one of the branches where nowadays elephants came from.

Modern elephant’s ancestors are not very clear as at the same era (second part of the Cenozoic) existed several important species that were very similar to present elephants. This three species were: Deinotherium, Gomphotheres and Mastodons.

  • Deinotherium- In life they were very similar to modern elephants but instead of having a large trunk they had it smaller and their tusks were curved downwards. They were one of the biggest terrestrial animals, they were between four and four point five meters high and their weights could reach fourteen tons. They were abundant in Asia, Africa and Europe.
  • Gomphotheres- They were similar to ones of present days but they had a different teeth structure, instead of two tusks, they had four and it is said that they had a trunk as modern elephants. They were more common in North America, but they were also found in areas of Eurasia and at the end of the period they colonized South America.

  • Mastodons-Even this specie was previous to the mammut one, they are not the same group. They shared many characteristics like: They were covered by a thick layer of fur. They had huge tusks of five metres long and four hundred kilograms. They appeared in Eurasia and from there they moved to Africa and America.

After this three groups which belong to the Proboscidea specie evolution took place and after some changes new specie was created, The Elephantidae family, where common elephant belong to.
Before nowadays elephants there were other species that gained many importance in evolution history
. Some of them were: the famous and very known Mammuts, which nowadays still being a reference in animal evolution, there are some subspecies from this kind of elephant like the African mammut, pigmy mammut, imperial mammut… This entire species had common characteristics like:

· Bigger than modern elephants, five point three meter high, nine point one meter long and a weight between six and eight tons.

· Dazed head curved tusks and muscled trunk.

· They had small ears, if they lived in warmer zones their ears were bigger.

The extinction of this specie was due to three main factor, climatic change, the human being by hunting them and some illnesses introduced by the humans or the animal that lived with them into many mammals species.

So this factors made that the elephantidaes with mutations that made them stronger and made them to survive easily to change till obatain modern elephants size, showing us by several tests that as we said before evolution is a fact.

This is all, we wish you like it and enjoy it. Good Bie.

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