Proliferation into a niche

[Spedley]

I've always thought of Survival of the Fittest as a negative feedback system.  It implies that the population is declining and that a single individual is responsible for the advancement of the gene pool - only the best survive.

Today I was struck that the bigger driving force of evolution is expansion into new territory.  Environmental boundaries, e.g. land/coastline, forrest/grass, plain/hills offer room for expansion aswell as a challenge for a species.  Individuals with the best adaptations will congregate on the boundary where resources are more plentiful.  Even small advantages will be shared through a healthy gene pool of similar individuals, multiplying the rate of evolution into the new niche.

I suspect that major changes could be achieved within very few generations under such conditions and that this is the real driving force of evolution.

[YaDinghus]

6 minutes ago, Spedley said:

I've always thought of Survival of the Fittest as a negative feedback system.  It implies that the population is declining and that a single individual is responsible for the advancement of the gene pool - only the best survive.

That is a common misconception. Don't worry about it, just be glad that you've escaped it. 

 

9 minutes ago, Spedley said:

Environmental boundaries, e.g. land/coastline, forrest/grass, plain/hills offer room for expansion aswell as a challenge for a species.  Individuals with the best adaptations will congregate on the boundary where resources are more plentiful.

Being able to use the resources better than others is part of being the fittest. And yes, moving into a new territory where the required resources are more plentiful is an advantage, because these resources are not available to (as many) competitors. The genes of such a group would thrive in such an environment.

However, another group which remained stationary could evolve to make use of resources which were unavailable because nobody else could process them. This is moving into a different niche.

Microorganisms of different species also thrive together due to specialization and exchange. Commerce is basically the beginnig of multicellular life

[naitche]

I  think the term 'survival of the fittest' would be better replaced with some thing that more accurately describes the process.

ie; delivery of value to the space occupied is favoured.

'Survival of the fittest' is used to support less than  ideal conditions .

[mistermack]

I don't think that proliferation into a niche is thought of as a major engine for change. The exact opposite is actually a more powerful factor, and that is a shrinking environment producing population "Islands" that cannot reach each other to exchange genes. As soon as a group gets cut off, you can get rapid specieation.

This is what the Galapagos finches showed. It wasn't the new niches that were responsible, it was the lack of breeding opportunities with the previous large populations. If the finches had been able to interbreed across the Islands, you wouldn't have got the specialisations.

Same goes for the tortoises. If there had been a land bridge for them to hop from Island to Island, you would probably have ended up with just the one species.

Adapting to a niche must surely play a part, but probably over a much longer timescale.