Why do animal clones die prematurely but plants can be vegetatively propagated (essentially cloned) many times over with no ill effects?

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I’ve read that for animals, say, a cloned mammal the DNA of the original host is the same used for the clone, so it’s already aged and degraded from time. I grow many plants, and so I regularly make clones via cuttings and divisions. So I wonder why the new individuals can have the same vigor as it’s parent plant? Does DNA not degrade in plants? I’ve also read that inbreeding can occur in plants. On a side note, about the super massive tree structure Pando, that Aspen forest from only like 1 tree I think. It’s estimated to be 80,000 years old and is technically a single individual, as every stem (tree) comes from the same roots and has the same DNA. Meaning at some point a long time ago a single seed made 1 tree which eventually became a forest occupying over 100 acres. How does DNA replicate so many times over in plants with no issues? Is it because the differences between plant and animal cells? I don’t know a lot about these things, just a random thought I had. Any explanation would be appreciated 🙂

In: Biology

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Anonymous 0 Comments

This works with lots of animals too, just not the ones that you are thinking about.

If you cut off a chunk of coral you can grow a new coral head from it, and in fact this is a common way for corals to spread in the wild (hurricanes or something breaks off a bit, it grows in a new spot). Some of the corals are thousands of years old.

There are other coral relatives that work this way, plus many worm species where if the worm breaks in half both halves can regenerate. Starfish can also reproduce this way. Probably some other invertebrate animals I am not thinking of. Many animal species that work this way just don’t seem to really age much at all.

Mammals and other vertebrates tend to have lots of controls on how much their cells can divide because it’s easy for them to be killed by cancer…lots of complicated plumbing for cancer to muck up, and cells that are mobile and can move around. But plants (and coral, and many other invertebrates) don’t have to be so worried about controlling their cell division because cancer isn’t able to kill them as easily (in plants, particularly, any cell dividing out of control can’t migrate to other parts of the plant). Furthermore, because their body structures are such that they _can_ reproduce by fragmentation, it makes sense for them to take advantage of that by not putting an “age limit” on their cells the way humans and many mammals do. You can’t just chop an arm off a human and regrow a new human from it, because an arm doesn’t contain enough of the body to be able to have everything it needs to regenerate. But half a worm would. Or a branch of a plant. Or part of a starfish. So it’s not really generic “DNA degradation” caused by environmental problems that is the main issue with cloning. It’s inbuilt DNA regulation that is hard to wipe away. Although plant “cloning” also has the benefit of you chopping off a whole branch with a bunch of cells. If one cell is messed up it just wont thrive and the others will take up the slack. Cloning from a single cell, like they do in mammals, means if that one cell has a problem the whole organism will have it.

Anyway, the DNA in these animals gets mutations just like in anything else (this is a seperate phenomenon from the inbuilt limits to replication you see in mammals that cause issues when cloning…and other issues which are due to epigenetic markers on the DNA). But mutation is a random process. Some cells might get hit by a bad mutation, others not. The unhealthy ones will die, the others will keep going…just like some offspring might be born with genetic diseases and die while others would be fine (remember, DNA in eggs and sperm is just like other DNA, it also gets mutations).

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