Question: Why did you decide to study fossils and what animals evolve the most from what they originally started?

Laura Soul answered on 11 Mar 2013:

I decided to study fossils because I fing evolution really interesting, and geology. When I went to university I was studying geology and part of that was studying palaeontology – about fossils and the rocks that they are found in. This was when I realised that studying fossils would be a really good way to combine my interests in evolution and geology. Then when I had to choose my first ever research project to do by myself the most interesting one was about brains of fossil animals, so that was why I decided for sure.

The second part of your question is a really good one. It depends a lot on how you define ‘amount’ of evolution, and the original starting point. The short answer is that we don’t really know for sure but under one definition it’s a type of moth as this seems to have gone through the most evolutionary changes in it’s genes. The animals that have evolved the least are probably things like sharks, crocodiles, cockroaches or horseshoe crabs that look really similar to fossils of their ancestors that we have found from millions of years ago.

If you want to read a longer answer, there are other ways of thinking about it. The first ever animal probably lived more than 700 million years ago, it might have looked a bit like the sponges that we see living in the oceans today and would definitely have lived in the sea. Obviously lots of animals are very different to this now.

Many scientists in my area of work define the amount of evolution as the rate of evolution, so how fast evolution happens. When you look at a fossil or a live animal it has lots of features, like whether or not it has skin or the shape of its bones. Scientists call each of these individual features a ‘character’, and the rate of evolution can be defined as how often these characters change. Lots of changes means a fast rate. If this definition is used then the animals that have evolved the most are probably big things like elephants or whales or maybe some dinosaurs. Scientists have shown that big things have higher rates of evolution.

Sometimes though things can evolve to have a character, and then they can evolve more and the character will change back again. So even though the rate of evolution is high, the animal might not look that different to it’s ancestors. So another way of defining the amount of evolution is to say which animal has the most features that only it has, so which animal is the most different to other animals. There is a special word for this – derived. An example of a very derived animal is the platypus. These are mammals like us (we know that because they have fur and feed milk to their babies) but they have loads of really weird features too, like they lay eggs, they have a thing like a beak, they have big flipper hands, they live in the water but not all the time and lots of their bones are really strange shapes and nothing like any other animal. So some people might say that this kind of animal is the most evolved becasue lots of very specific evolutionary changes have happened to it that haven’t happened to anything else.

Some people say that humans are the most evolved, I’m not sure that I agree though! Although we have really really big brains compared to our size, and no other animal has this, in a lot of ways we are very similar to other primates like apes, we haven’t changed that much from them, and primates have been around for longer than some other groups of animals. I think lots of people might disagree with me though, and they have lots of good reasons.

So this was a really good question because there are many different ways of looking at it, no one is sure of the answer yet, lots of people are thinking about it and trying to figure out the answer, and scientists have arguments about this sort of thing all of the time! Maybe you could be the one to figure it out…