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Author Topic:   Somewhere between Darwin and Baldwin lies... Lamark?
Nuggin
Member (Idle past 600 days)
Posts: 2965
From: Los Angeles, CA USA
Joined: 08-09-2005


Message 16 of 17 (247278)
09-29-2005 11:25 AM
Reply to: Message 15 by Omnivorous
09-29-2005 11:09 AM


Re: selection is as selection does
Perhaps the Heike crab is a good example, where for centuries Japanese fishermen have released crabs whose shell markings are thought to resemble a samurai's face. Both the number of such crabs and their likeness to samurai faces have increased; the resemblance-bearing individual crab has increased chances of survival (and reproduction), and, it seems to me, so does the species, since there is now a large subpopulation we will not so readily hunt into extinction.

Sure, but the first crab which had this feature didn't "strive to have a face on his back". It just happened. Then, as a result, he lived and had kids that had similiar markings.

It's even possible that multiple crabs independantly developed face-like features on their backs, since, I'm assuming here, all these crabs have some feature and it's really subjective on the part of the fishermen what is face-like.

In the mouse study, according to Larmarkian evolution, a tailless mouse would be born in short order as a result of cutting off the tails of the parents. It's important to the study that every mouse survive to reproduce (since cutting the tail off is what is causing the change in the future generation).

What I'm saying is that if you have two groups of mice. One group as a control. The other gets it's tail cut off. And every mouse is raised to reproduce. Eventually (maybe a thousand years of this, but eventually) you'll get a mouse born with no tail. However, that mouse is as likely to be born to the control group as the tailless group. The mutation that causes taillessness is not caused by tail amputation

This message has been edited by Nuggin, 09-29-2005 11:26 AM


This message is a reply to:
 Message 15 by Omnivorous, posted 09-29-2005 11:09 AM Omnivorous has responded

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 Message 17 by Omnivorous, posted 09-29-2005 1:01 PM Nuggin has not yet responded

    
Omnivorous
Member (Idle past 1075 days)
Posts: 3808
From: Adirondackia
Joined: 07-21-2005


Message 17 of 17 (247305)
09-29-2005 1:01 PM
Reply to: Message 16 by Nuggin
09-29-2005 11:25 AM


Re: selection is as selection does
Nuggin writes:

What I'm saying is that if you have two groups of mice. One group as a control. The other gets it's tail cut off. And every mouse is raised to reproduce. Eventually (maybe a thousand years of this, but eventually) you'll get a mouse born with no tail. However, that mouse is as likely to be born to the control group as the tailless group. The mutation that causes taillessness is not caused by tail amputation

Agreed. Sorry if I was unclear and seemed to argue otherwise.

The speculation I was supporting is that the continued chopping of tails in the "Farmer's Wife" cohort could act as a selective pressure that favors the genetically tail-less mouse.

With the tail-less mutation-bearing mouse free from the risks of traumatic injury, and, perhaps, therefore more desirable as a mate, the tail-less mutation might spread throughout that isolated cohort.

Similarly, an antibiotic may not cause the resistant mutation, but the outcomes may differ dramatically between antibiotic-present and antibiotic-absent cohorts of bacteria when a new resistance mutation appears.


This message is a reply to:
 Message 16 by Nuggin, posted 09-29-2005 11:25 AM Nuggin has not yet responded

    
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