Question on Predators/ NS

Discussion of everything related to the Theory of Evolution.

Moderators: honeev, Leonid, amiradm, BioTeam

Post Reply
AFJ
Coral
Coral
Posts: 146
Joined: Mon Feb 23, 2009 1:59 pm

Question on Predators/ NS

Post by AFJ » Tue Jul 28, 2009 4:01 pm

How much research has been done the role of feral species who may upset the food chain like the asian carp in the Mississippi, or cain toads in Australia? How much factor would this be in natural selection?

Darby
Viper
Viper
Posts: 1278
Joined: Thu Mar 02, 2006 5:29 pm
Location: New York, USA

Post by Darby » Tue Jul 28, 2009 8:11 pm

It can be a significant change in a local ecosystem, which is what drives selection. "Natural" in this case is just a label - any population affected by the appearance of carp, etc, will either adapt over subsequent generations...or not. It doesn't matter to them where the carp came from, or how it got there.

AFJ
Coral
Coral
Posts: 146
Joined: Mon Feb 23, 2009 1:59 pm

Re: Question on Predators/ NS

Post by AFJ » Tue Jul 28, 2009 11:37 pm

I don't mean to be an agitator. I'm just asking myself the question how are a bunch of carp eating everything in sight and multiplying without control going to be a mechanism for variation in the genome?

User avatar
canalon
Inland Taipan
Inland Taipan
Posts: 3909
Joined: Thu Feb 03, 2005 2:46 pm
Location: Canada

Post by canalon » Wed Jul 29, 2009 1:35 am

They are not. No predator is going to create any variations in the genome. The only thing they can do is to select for variations that would make the prey less likely to be eaten by the carp (better avoidance, bad taste,...). Those varaiations would have existed even without the carp, but they have now a strong advantage compared to other variations and will be able to thrive as would never have done without the carp.

Alternatively the carp is going to hunt all prey to death, and the carp population is going to collapse because the ecosystem will not be abl to support it. Then prey are going to multiply again and if there are enough prey the carp population is going to follow repeating the cycle until one of the population is unable to regenerate from the collapse.

Examples of both situations are found.
As for the "natural" selection it was used by Darwint toppose it to the human selection carried out by breeders, but the models are valid even for the non natural invasion of an ecosystem. I do not really see your point. In fact, this would belong more to the ecology forum.
Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)

AFJ
Coral
Coral
Posts: 146
Joined: Mon Feb 23, 2009 1:59 pm

Re: Question on Predators/ NS

Post by AFJ » Wed Jul 29, 2009 2:08 am

My point is that Darwin said natural selection was the mechanism for evolution-right? I don't see how that's ever going to happen. The scenario you gave is very good, and natural selection is evident. But you have to have new information in the genome, and NS is taking away from the gene pool through extinction. Am I missing something here?

User avatar
AstusAleator
King Cobra
King Cobra
Posts: 1039
Joined: Tue Jan 24, 2006 8:51 pm
Location: Oregon, USA

Post by AstusAleator » Wed Jul 29, 2009 2:16 am

AFJ wrote:Darwin said natural selection was the mechanism for evolution-right?


Modern evolutionary theory relies on more than just selection. It must be combined with mechanisms capable of increasing or changing genetic information in order to produce new organisms.

In the case of aggressive invasives - the invader may extirpate native populations before any advantageous mutations or adaptations can occur or become established.
What did the parasitic Candiru fish say when it finally found a host? - - "Urethra!!"

User avatar
futurezoologist
Coral
Coral
Posts: 131
Joined: Tue Jun 10, 2008 12:21 pm
Location: Western Australia

Post by futurezoologist » Sun Aug 09, 2009 12:14 pm

Random mutations give rise to new genetic material, this along with natural selection brings about a variation from the original 'stable' genome.
Example with the carp - an 'original' fish is competing with this introduced carp population for food, the original fish are being out competed and so are dying out, one of these original fish developes a slightly longer nose through a mutation, this gives it an advantage because it is able to reach food between rocks etc that the carp can't so this gene becomes more common etc etc.

You get the point. This is variation from the original genome.
A wise man once said to me:
"Build a man a fire, and he'll be warm for a day. Set a man on fire, and he'll be warm for the rest of his life."

Only the fittest chickens cross the road.

Post Reply

Who is online

Users browsing this forum: Bing [Bot] and 10 guests