Scientists are questioning whether animals getting bigger in nature is because it is generally beneficial and linked with an increase in biological fitness. Over time some species have got bigger and that possibly all animals have evolved to get bigger throughout history.
Copes Rule says Animals will Get Bigger
Edward Drinker Cope was an American Palaeontologist who studied fossils, in doing so he noticed certain trends that meant some animals, mostly mammals had increased in size over their evolutionary history. Until recent scientists started to research this rule, it was mostly seen as an opinion that lacked scientific data to back it up.
Studies Have Confirmed Copes Rule
researchers put together a massive database of marine animals containing the body measurements of 17,208 genera. The data was from the present but ran all the way back in time to the Cambrian explosion about 50 million years ago, that’s a lot of data. After inputting this into a computer programme they were able to analyse patterns in the changed of body size over the last 500 million years or so.
they found not only that animals have increased in maximum size up to 100,000 times in this time, but that also the smallest ones have gotten even smaller, by a factor of about 10. They noticed that the most diverse species today have grown the most over time and this was thought to be because bigger animals can swim farther and so be subjected to different factors.
The current research was done on marine animals and there is suggestions that Copes rule wont apply to all animals at all but more research has to be done on this subject before we can make any more definitive conclusions.