Evolution in Islands

Discussion of everything related to the Theory of Evolution.

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David George
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Evolution in Islands

Post by David George » Mon Feb 27, 2006 9:34 am

Canalization is a process by which developmental process becomes insensitive to environmental and genetic fluctuation. There is some 'buffering' that is built up so that it becomes very stable. I like to view it as a bumper on a car, or even the crumple zone. External impacts are minimized by these processes. Selection will rapidly cause the phenotype to become stabilized to that environment. This process is called canalization and is a form of adaptation. Just like fish that move to a cave. They will eventually lose their ability to see. Energy conservation is a major factor. Yes, these fish would be at a disadvantage if they were brought out of the cave and that's because they have evolved to lost the ability to see.This does mean that organisms evolving in an island evolve faster and hence greater bio diversity is seen but due to canalization the tend to stop evolving phenotypically hence when an island merges with a mainland the organisms in the island are weaker due to canalization and they are more specific to one type of climate,place or even a tree.Ex when India was an Island it should have had many species but when it merged with Asia it lost its endemic species.

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Post by Khaiy » Tue Feb 28, 2006 2:47 am

That makes sense, it sounds a lot like allopatric speciation to me. New environmental pressures located in an isolated area cause devergence from evolutionary patterns of animals in other areas, with other pressures. And if the isolated group comes into contact with the mainland then they need to adapt to the new pressures, and compete against a similar species which has already adapted to them. Eventually these new groups would die out, find a new niche, or compete with the existing group, and this would create new adaptive pressures, leading to a new round of adaptations.

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alextemplet
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Post by alextemplet » Tue Feb 28, 2006 2:53 am

Another example would be when North and South America collided. When the two collided, species on both migrated to the other continent and other species died out due to the new competition.

What about the spread of humans across the planet? We already know we're affecting our environment, but perhaps studying what happens when a new species arrives on an island, especially an apex predator, can show us on a small scale what we're doing ourselves. It might help us better understand what's going on and be able to control it.
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