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Asked by to Amelia, Clem, Izzy, Sarah on 14 Mar 2014. This question was also asked by .
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Isabel Webb answered on 14 Mar 2014:
There is lots of proof that plants have come from evolution – just like how all other organisms came from evolution.
We can look at the DNA of a plant and find bits of DNA that match other similar plants. We can then trace it back and look at fossils, to show how different plants are related. Scientists create ‘phylogenetic trees’, which is like a human family tree. These trees show us which plants are related and which aren’t.
Sometimes a newly evolved plant develops because the seeds of an old plant blew somewhere new, and so the plant had to adapt to its new surroundings. We can then look at both the old and new plant and show that their DNA mostly matches, but there are a few changes because of the area around them.
Sometimes we see the same feature evolve completely independently – a good example is bats and birds. Both bats and birds evolved wings, but they evolved them separately – and we can see this if we look at their bones. Bat wings are extensions of the fingers but bird wings are all along the length of the arm. We can see this same type of separate evolution in many plants.
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Sarah Harvey answered on 14 Mar 2014:
Izzy’s answer covers a lot of what I was going to say!
Also what you can do is experimental evolution, for example you can look at changes which just happen over a couple of generations. So if you grow plants under really stressed conditions and you’ll see that over a few generations they are able to cope with the stress a lot better as natural selection will favour those that can survive! A good example is weeds that become resistant to herbicides used when growing crops. This gives us a tiny snippet of the same process which happened over millions of years!
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Clemence Bonnot answered on 16 Mar 2014:
Plant as all other living thing have evolved from the first ever form of life of earth (presumably a very simple type of bacteria). Looking at the DNA sequences of all cellular living things of earth we can find so many similarities (even in the ways the cells work) that it is sure that all earth living things have a common ancestor. Yes we as humans have a common ancestors with plants,and fungi and bacteria. We have even more in common with plants than bacteria because we both come from an ancestral cell that had a nucleus contrary to bacteria.
Looking at DNA sequences of the genes present in living cells we can reconstitute a genealogical tree call phylogenetic tree of the living species. Doing that we have been able to show that land plants have evolved from a certain family of pound water algae. This algae family itself evolved from see water algae. Once on earth the first land plants were very similar to liverwort or mosses and where very tinny not more than one millimeter. Just like dinosaurs we have found traces of these primitive plants in rock as fossils. Since, many more land plants families have evolved from these primitive plants. One of the last to appear in the fossil record are the flowering plants but they are the most adapted to life on land and represent around 80% of the plants. -
Amelia Frizell-Armitage answered on 16 Mar 2014:
As everyone has said there is lots of evidence for evolution when we look at living plant DNA as well as fossils.
An additional point is that as well as DNA we can also look at the plant physiology, that is how the plant looks, works and stays alive, to find evidence of evolution.
Most of the plants alive today are modern plants and have evolved relatively recently. However, there are a few ancient plant species still around. For example a group of plants called Horsetails first evolved 375 million years ago and were very common when there were dinosaurs on the earth. These plants evolved before seeds did, so they don’t reproduce using seeds but with spores in a similar way to fungus. Another example is the Liverwort. These plants look at bit like mosses and evolved before flowering plants. The systems inside their bodies work completely differently to modern plants and show what some of the first plants would have been like.
Using these ancient species we can trace back the order that different plant parts changed and evolved. This way we can understand what ancient plants were like and how modern plants evolved from these.
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