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Author Topic: Is body modification reflected in our genes?  (Read 1903 times)

Amber Casares

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Is body modification reflected in our genes?
« on: 14/07/2012 12:16:33 »
Amber Casares  asked the Naked Scientists:
   Hello Chris,

Do our bodies "know" when we've made an artificial change and will it remember for future generations? And if enough human beings make that same change, will humans eventually evolve into something that will not require the artificial change?

For instance... if small breasted women get augmentation and then have daughters who gets augmentation and their daughters too... will that blood line eventually produce larger breasted women?

Thank you!
Amber Casares
Worcester, Massachusetts

What do you think?
« Last Edit: 14/07/2012 12:16:33 by _system »


 

Offline chris

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Re: Is body modification reflected in our genes?
« Reply #1 on: 14/07/2012 12:38:31 »
Dear Amber

Thanks for the interesting question!

The answer though, is no; direct changes to the body will not be reflected in a genetic change favouring that characteristic in subsequent generations.

This was actually an idea - dubbed "inheritance of acquired characteristics" - that was advanced originally by the French naturalist, Lamarck. He argued that responses to life experiences would be passed on heritably to subsequent generations. This was later laid to rest by the German evolutionary biologist Friedrich Weismann, who chopped the tails off 5 successive generations of mice, proving that those conceived later still nonetheless had tails as long as the founding parents.

A similar experiment has also been taking place naturally among humans for thousands of years in the form of circumcision - removal of the foreskin - for religious and hygiene purposes; yet despite the long history of the practice, foreskins are not vanishing in circumcising populations, which is why parents still need to request the procedure for their sons.

That said, the act of altering the body in some ways can still affect the gene pool indirectly; so the breast-augmented female, or the circumcised male, might, under certain circumstances, enjoy greater reproductive success, meaning that their genes are more likely to be passed on to the next generation. And this could, paradoxically, keep genes in the population gene pool that would otherwise have been lost.

For example, say the world's exclusively populated by a tribe of shallow men who will only date 36DD (or bigger) females. Left to natural selection, and assuming that this Lara Croft style preference is maintained, the female population would naturally evolve towards a bigger-busted phenotype because women with genes endowing them with big bosoms would mate more often. But with breast augmentation available, everyone can be 36DD+, even if their genes say otherwise. The genes for smaller breasts would, under these conditions, therefore persist in the population where previously they would have become less prevalent.

And for the male example we considered earlier (for the sake of equality!), men with genes that could cause a tendency towards foreskin problems, like phimosis or balanitis (infection), would be selected against in a non-circumcising population. But routine population circumcision means those genes remain in circulation with a higher frequency.

Similarly, some also argue that increasing incidence of birth by caesarian section may also be selecting for a population of females incapable of giving birth naturally... what a thought to end on...
« Last Edit: 14/07/2012 12:41:14 by chris »
 

Offline RD

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Re: Is body modification reflected in our genes?
« Reply #2 on: 14/07/2012 12:54:45 »
Glad to hear body modifications are not inherited: one Goatboy is more than sufficient.
« Last Edit: 14/07/2012 12:57:39 by RD »
 

Offline CliffordK

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Re: Is body modification reflected in our genes?
« Reply #3 on: 14/07/2012 12:58:55 »
It is possible that a feature that would make body modifications easier might be slected for.

For example, non cartilaginous ear lobes might make ear piercing easier.

Then, if pierced ears increased mating success...  the feature would be selected for over time.
 

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Re: Is body modification reflected in our genes?
« Reply #3 on: 14/07/2012 12:58:55 »

 

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