• Question: how do you know that the theory of evolution happened, do you have any relevant evidence to proceed this research?

    Asked by littlemisstiger to Davie, Gemma, James P, James V, Nuala on 3 Jul 2012.
    • Photo: James Pope

      James Pope answered on 3 Jul 2012:

      Hi littlemisstiger,

      In palaeoclimate work we spend a lot of time working with palaeontologists who gather fossils of both large species and microscopic life. When you look at all these species you can see how they evolve from one species to a couple of similar species and it is really easy to see Darwin’s theory in action. We can see the adaptations the species makes over millions of years to live in changing conditions, this is really clear in micro-fossils because we have millions of them to study! Adaptations are the changes that evolution happens through, such as the longer neck of the giraffe and the stripes of the zebra, although they all happen slowly over many generations, the beneficial adaptations surviving and the less beneficial ones dying out.

      Personally, I am also very good friends with a evolutionary biologist. We knew each other at Edinburgh University and Fiona now works on her PhD at the University of Exeter. Fiona did a lot of work with flies called Drosphelia, which reproduce quickly and have a short natural lifespan. Fiona investigates how changing the environment these flies lives in changes the preferences the flies have for mating to investigate if envrionmental factors get in the way of natural evolution of the flies.

      The development of an eye is the best example of how evolution works. Imagine you are a blind fish, using vibrations in water to sense your way around. A mutation means that an adaptsation occurs causing your offspring develop a cell on their face that can sense the change from light to dark, it can ‘see’ shadows. This means your offspring are more likely to survive and mate and have their own offspring, most of whom have this light sensor cell on their face. Over time the mutation continues and more and more of these light sensor cells form. Over millions of years, these cells form the retina, and other parts develop around them, such as the lens and the pupil. All of these adaptations come together to form an eye, through a process of elimination, good developments survive, bad ones die out.

      The same is true of our own species, the ones who came out the trees and could stand on two legs, outsurvived those who squatted on four legs as they could see predators coming. Evolution is very fair, but also very harsh for those who lose out.

    • Photo: James Verdon

      James Verdon answered on 3 Jul 2012:

      Hi littlemisstiger,
      We can see evolution happening all around us. Have you ever heard about antibiotic resistance? We treat disease causing bacteria with antibiotics. However, these bacteria are now starting to become resistant to the antibiotics, due to evolution. Let’s say a patient is being treated with antibiotics. Almost all of the bacteria are killed. However, one bacteria has a random mutation that makes it immune to the antibiotic. So this one bacteria can survive and carry on breeding. This bacteria replicates and replicates, and all the new bacteria produced are resistant to the antibiotic, and suddenly you now have a population of bacteria that are now immune. These can now spread and infect other people, and hey pesto! Thanks to evolution, we have a new strain of antibiotic resistant bacteria. MRSA is perhaps one of the best known examples of this.

      Bacteria breed and reproduce incredibly quickly. This means that they are capable of evolving very quickly, so bacteria are the best examples to see evolution in action. Because most large animals take a long time to breed, and don’t produce many offspring, it takes a long time for evolution to take effect, so we can’t see it happening like we can with bacteria.

      The study of bacterial mutation and evolution is a really important area of research, because it has huge implications for developing the next generations of antibiotics that we will use to treat diseases. So there are loads of scientists (and pharmaceutical companies) who are using evolution in their everyday jobs.