Thread: Natural selection

Hi !

Considering the optimizing character of natural selection can we expect that organisms may be perfectly adapted to their environment ?

Thank you and happy new year
Vince

Ps: Sorry if there are some grammatical mistakes, english is not my mother tongue...

Originally Posted by Naemoekey

Hi !
Considering the optimizing character of natural selection can we expect that organisms may be perfectly adapted to their environment ?

Wouldn't use the word "perfect." Some organisms are very well suited to their environment. That may seem like a boon- unless their environment changes...

And natural selection is hamstrung by numerous limitations--the mutations need to happen, the better adapted organisms stand a better chance if they are isolated in some way, and perhaps most notably the existing genetics severely constrain evolution.

You don't have to be perfectly adapted at all. Nature has a niche for almost all evolutionary expressions.

Hydrothermal vent - Wikipedia, the free encyclopedia

And also some less than perfect species may thrive in a sheltered environment with little change.

Silvery Salamander - ArborWiki - Ann Arbor

Many thanks for your answers !

I would say they are a more direct result of their environments which would make them more suitable to survive in there environments

Originally Posted by warthog213

I would say they are a more direct result of their environments which would make them more suitable to survive in there environments

I agree.

And it does not preclude several species or variations to thrive in a shared environment.

Originally Posted by Naemoekey

Considering the optimizing character of natural selection can we expect that organisms may be perfectly adapted to their environment ?

No, we would not expect that.

Optimize means something like " to make as useful as possible", or "to make the best of what is available". That is different from achieving perfection.

Natural selection can only act on what is available, and if random mutations fail to provide the raw material needed for perfection in a given environment then perfection cannot ever be achieved, regardless of how effective natural selection is.

Okay so if I've well understood, to sum up, natural selection can't produce organisms perfectly suited to their environments because:

-There are constraints due to evolutionary history, evolution is constrained by traits they have already evolved.
-The lack of necessary genetic variation.
- Natural selection is more natural elimination of what doesn't work rather than the selection of the best.

And after some research I find others reasons:
-mecanic constraints
-trade-offs, changing one feature for the better might change another for the worse.
-the fact that the environment is constantly changing so the species spend more time climbing adaptative peaks than they do sitting at the summit optima.

So far, so good. You might also do some reading and browsing at talkorigins.org to increase your understanding.

Originally Posted by Naemoekey

- Natural selection is more natural elimination of what doesn't work rather than the selection of the best.

That could be misleading. I think this would be a better way of putting it.

Natural selection is the selection of the best that is available through the preferential elimination of what is less than the best available.

Many thanks for your answers !
See you very soon for other questions

Originally Posted by Naemoekey

Okay so if I've well understood, to sum up, natural selection can't produce organisms perfectly suited to their environments because:.

I think you should avoid the term "perfect" altogether, since it is generally an ill-defined and unattainable thing. What exactly would a perfect creature look like? One that can't die?

A thing to remember is that no organism exists in a vacuum. Each organism is part of an ecosystem, so at best it can be in a rough equilibrium in that niche it finds itself in. Consider also that an organism that is not in equilibrium can either die out due to competing poorly for resources, or die out eventually after overconsumption of resources.