R
reznwerks
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"A new study of tropical reef fish calls into question a modern theory for how species develop and supports Darwin’s original idea of ecology as the driving force of speciation.
Natural selection by itself can cause an advantageous gene – say a longer neck on a giraffe – to spread among interbreeding organisms. But in order for evolution to explain the emergence of two distinct species, some sort of "wedge" needs to exist that drives populations apart.
Darwin thought that the distinct survival pressures in different habitats were enough to cause new species to form. But in 1942, Ernst Mayr developed a theory that populations had to be isolated geographically – such as by a mountain range or a glacier – in order to form separate gene pools, where random genetic mutations would generate divergent species. "
http://www.livescience.com/animalworld/ ... _fish.html
Natural selection by itself can cause an advantageous gene – say a longer neck on a giraffe – to spread among interbreeding organisms. But in order for evolution to explain the emergence of two distinct species, some sort of "wedge" needs to exist that drives populations apart.
Darwin thought that the distinct survival pressures in different habitats were enough to cause new species to form. But in 1942, Ernst Mayr developed a theory that populations had to be isolated geographically – such as by a mountain range or a glacier – in order to form separate gene pools, where random genetic mutations would generate divergent species. "
http://www.livescience.com/animalworld/ ... _fish.html
