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(Permalink) Posted: Nov. 11 2011,09:23   

Quote (Southstar @ Nov. 11 2011,08:56)
Okay I get it but supposing we do some tests on generations of Drosophila, cause they're quite easy to breed and we can do a nice time lap test on them.

But instead of doing it out in the open we do it in in a lab, where the happy flies have really eveything they need. Esentially what we are doing here is eliminating natural selection.

Since we know that mutations happen and they are cumulative. Sooner or later all the build up of cumulative random stuff has got to give way, but after thousands of generations we end up with essentially the same bug.
Shouldn't the random cumulative mutations change the bug into a random (but functional) version of a new bug.

Am I making any sense?

Do we?

No one has done these experiments for thousands of years.  Yet, we do know that speciation can occur within one generation.

We also have Lenski's data of E. coli research over the last 25 years.

Now, look at what happened in Lenski's lab.  One of the defining characteristics of E. coli is that inability to metabolize citrate.  That character is how researchers determine the difference between E. coli and (IIRC) Salmonella.

Yet, Lenski, through natural selection and random mutation has discovered a E. coli strain that can utilize citrate.  If this had occurred in non-bacterial species, it would probably be sufficient for it to be declared a new species.  Bacteria... meh.

Likewise, it also depends on how you define "something different".  Are dachshunds exactly the same thing as wolfhounds?  No, are the different species?  Honestly, that question is pretty meaningless.

Dachshunds and wolfhounds can interbreed and have grandchildren (i.e. the F1s are not sterile), but so can domestic cats and servals, so can lions and tigers, and we 'know' those are different species.

Species aren't nearly as static or fixed or separate as most people would think.  So the question is really moot.  Yes, they might still be fruit flies, but the only way to determine if they could interbreed with fruit flies of a 1000 years ago would be to (somehow) get some fruit flies from a 1000 years ago and try it.

Which leads me to a really good question to all.

Could an organism (say human or dog) successfully interbreed with a member of the same species from a thousand or 6000 years ago?

For example Diplodocus has a known time range of almost 4 million years.  Do you think that the later members would be sufficiently different from the earlier members to prevent breeding (which is one definition of species, which IMHO is sorely lacking as evidenced above).

Things are not just cut and dried in Biology, no matter how much some people wish or claim that they are.

Ignored by those who can't provide evidence for their claims.

  366 replies since Nov. 08 2011,06:46 < Next Oldest | Next Newest >  

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