I've just read a very interesting book entitled Why Evolution is True by Jerry A. Coyne and there was one particular chapter that enthralled me. It was about genetically modified modern crops, such as wheat and corn, but rather than explain in layman's terms how such crops have become prevalent, it assumed an inherent level of knowledge about the subject that, sadly, I do not possess.
Can anyone on here explain in relatively simplistic terms how these polyploids have been created by Man? I am able to grasp the general principle but would appreciate someone offering an "Idiot's Guide".
Genetics and polyploidism
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Padfield
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Re: Genetics and polyploidism
Taking you at your word, if you are really a beginner when it comes to genetics, you might try Pete's introduction to butterfly genetics here:
http://www.ukbutterflies.co.uk/reports_ ... p#genetics
Although he doesn't deal with polyploidy (animals are less tolerant of this than plants, though it has played its part in the evolution of all of us) he does explain many of the basic genetic terms and concepts. Armed with an understanding of the normal, diploid state, and how it is passed on from generation to generation, your book's discussion of artificially induced 'evolution' might make more sense.
Also, he spent a lot of time writing it and it's worth a read!!
Guy
http://www.ukbutterflies.co.uk/reports_ ... p#genetics
Although he doesn't deal with polyploidy (animals are less tolerant of this than plants, though it has played its part in the evolution of all of us) he does explain many of the basic genetic terms and concepts. Armed with an understanding of the normal, diploid state, and how it is passed on from generation to generation, your book's discussion of artificially induced 'evolution' might make more sense.
Also, he spent a lot of time writing it and it's worth a read!!
Guy
Guy's Butterflies: https://www.guypadfield.com
The Butterflies of Villars-Gryon : https://www.guypadfield.com/villarsgryonbook.html
The Butterflies of Villars-Gryon : https://www.guypadfield.com/villarsgryonbook.html
Re: Genetics and polyploidism
Hi David,
You might find this article helpful: http://users.rcn.com/jkimball.ma.ultran ... loidy.html
It's important to realise that plants are fairly prone to doubling up their chromosomes when they reproduce (it can happen in some animals but is rare) Normally, if two different species are crossed then the offspring are sterile. If polyploidy occurs, then it is possible for the polyploids to reproduce with one another (though not with one of the original species) Because of this, the new polyploid is, effectively, a new species. Some plants do this spontaneously quite frequently, so that almost every individual is a separate species - a huge problem for taxonomists!!
It is thought that several thousand years ago, two different grasses crossed and the natural creation of a few polyploids led to a new fertile species, which we call 'wheat'. This had those desirable properties, which made agriculture possible. Similar events in different parts of the world led to the various 'staple' crops.
It is only recently that we have learned how to increase the rather small spontaneous rate of polyploidy by means of drugs, which greatly increase the frequency of the process. Thus, it is possible to create new species relatively quickly and select those which have desirable properties for agricultural purposes.
I should point out that I am not a qualified biologist, merely an interested layman, but I hope that this outline is helpful.
Mike
You might find this article helpful: http://users.rcn.com/jkimball.ma.ultran ... loidy.html
It's important to realise that plants are fairly prone to doubling up their chromosomes when they reproduce (it can happen in some animals but is rare) Normally, if two different species are crossed then the offspring are sterile. If polyploidy occurs, then it is possible for the polyploids to reproduce with one another (though not with one of the original species) Because of this, the new polyploid is, effectively, a new species. Some plants do this spontaneously quite frequently, so that almost every individual is a separate species - a huge problem for taxonomists!!
It is thought that several thousand years ago, two different grasses crossed and the natural creation of a few polyploids led to a new fertile species, which we call 'wheat'. This had those desirable properties, which made agriculture possible. Similar events in different parts of the world led to the various 'staple' crops.
It is only recently that we have learned how to increase the rather small spontaneous rate of polyploidy by means of drugs, which greatly increase the frequency of the process. Thus, it is possible to create new species relatively quickly and select those which have desirable properties for agricultural purposes.
I should point out that I am not a qualified biologist, merely an interested layman, but I hope that this outline is helpful.
Mike