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Monday, June 8, 2009

Cloning

What: Clones


Who invented it? Farmers

No, I'm dead serious! The first clones were of plants and done as basic grafts and transplants of cultivars. Cloning started as science, not fiction.



What is it?
1) Cloning is the technique of taking a genetic code and duplicating exactly to produce a matching specimen.

2) In fiction, cloning is the process of creating a set of identical specimens, often with genetic extras, that are indistinguishable from one another at any level.

3) Identical twins are a form of natural cloning. The fertilized egg in a mammalian uterus splits into 8 basal cells rather than four. They separate, and you have genetically identical twins. To a point... the mammalian genome is complex.


Do We Have It? Yes

To a limited degree we have cloning. But it isn't the perfect fiction people like to believe in. The cloning techniques we currently have allow genetic duplication. We can not control future changes to the genome (naturally occurring mutations) or predict variations in mental function or personality.

How Does It Work?
On the simplest level cloning uses the same techniques as creating a designer virus.

Yes, I know, some of you don't go a gen-engineer viruses in your spare time.... Here's the simple version for a mammal:

Genetic material is removed from the target specimen and inserted in an emptied cell (egg, uterine, generic...) and the new "egg" implanted into a host uterus.

In a normal fertilization of an egg two different sets of gametes are combined. In cloning there is only one set of gametes.

This does happen naturally in some species.




Will We Ever Get "Star Wars" Clones? Probably not.

One of the things fiction writers like to ignore is that the cells that set your life in motion aren't the ones you die with. Every day your body is replicating your cells and a tiny mutation today can have long-term consequences. And it's completely unpredictable.

This is especially true in cases of unexpressed genes. Think calico cats or hair color.

The patchwork pattern you see on a calico cat is actually determined by an X-linked allele. In each individual cell one of those colors will be dominant. A clone with an identical genome may not express the same pattern of dominance.

Which means your cloned calico cat may not look like their genetic twin.

A genetic match is not the same as an identical individual or specimen.



The BIG Question: Really, the big question is ethics. Should cloning be allowed?

But, let's keep it simple. Should DNA of extinct species be used to clone and revive a species?

A bonus cookie for anyone who knows what species they actually tried this idea on and what happened (and, no, I don't mean Jurassic Park).

4 comments:

  1. I've always wondered why cloned animals didn't necessarily look identical to the originals--thanks for explaining in plain English!

    I'm going to say a 'no' to cloning, even extinct species. It doesn't seem like a good idea to just reintroduce a species to a current ecosystem--too much damage possible. Was the extinct species they tried to clone the dodo bird?

    But (I think) I'm in favor of cloning organs, like hearts, livers etc. for transplant patients. As long as they're reeeeally reeeeally careful with it.

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  2. Not a dodo.... tempting thought though.


    Cloning organs is actually a whole other process. Ideally it would use undifferentiated (stem) cells. But getting those in an ethical manner that doesn't suggest creating a fetus just to kill it is difficult. As is getting the undifferentiated cells in large portions.

    I'll save that post for another week!

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  3. Bring back the dodo!

    I'm with the 'no' though. Messing with nature isn't a good idea. You can't predict what'll happen. I'm not even for cloning organs. No no no no no. Unfortunately, human bodies go wrong. People need to accept some things aren't meant to be fixed.

    (apologies: I'm tired, cranky, possibly had too much sugar and caffeine this morning and am now slumping)

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  4. I would say no to the cloning of individuals. But I'm open to doing something about organs.

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