• Question: How can plants evolve

    Asked by to Amelia, Clem, Izzy, Sarah on 18 Mar 2014. This question was also asked by .
    • Photo: Isabel Webb

      Isabel Webb answered on 18 Mar 2014:

      Everything on Earth evolves in the same way – a mutation happens in the DNA, and survival decides if that mutation stays or goes. If a mutation is either neutral (no effect) or beneficial (helps it survive better), the organism will stay alive. Sometimes these mutations lead to a physical change, which could help the plant survive better than the other plants around it. The better surviving plant will win in the end, because they out-compete the others for light or food or water. Eventually, that ‘mutant’ plant will become the only plant left. That plant might then get a new mutation, helping it to survive even better, and so again, it wins and survives.

      Evolution is a constant battle for survival, and plants need to survive too. If a plant evolves bigger leaves, it can catch more light and make more energy, and might also shade the smaller plants around it. This new plant will win, and breed, and so all the plants in that species will have bigger leaves.

      A new species occurs when enough changes have happened that mean that the new plant and old plant can’t breed with each other any more.

    • Photo: Amelia Frizell-Armitage

      Amelia Frizell-Armitage answered on 19 Mar 2014:

      Every living thing on earth has evolved to be the way it is, and is still evolving, because life is just one huge competition between all individuals.

      Living things are constantly trying to adapt to be better in their environment. For example plants that live in soils with not many nutrients in them do better if they have longer roots, and plants that live in very windy places do better if they are shorter. The individuals that are best adapted will out compete all of the others and get all of the best resources – they will get the best mates, the best food, and the best habitat. Other individuals that are not so well adapted end up getting all of the worst resources and can die. In this way the best adapted survive and worst adapted go extinct. As things adapt they change. Usually these are only very small changes, but if enough small changes happen you end up with a new species!

      This process takes hundreds of millions of years. However, it explains how all species on earth evolved from one single cell organism, and is still going on today. Probably in a few thousand years time a lot of the species we know today will have been replaced by new ones!

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