Question

Had this question on an Ecology exam earlier today. Wanted to see what everyone thinks.

"Darwin explained evolution as 'survival of the fittest'. What would be a better way to phrase this statement? Specifically, why does fittest, not really...fit?"

Answer 1

It would be more appropriate to say that "survival of the most adaptable". Organisms which adapt best to their changing surroundings have the highest chance of surviving the change.

Answer 2

I agree. The more adaptable animals are likely to survive natural disasters and other such sudden changes in their environment. The word 'fittest' is kind of misleading here.

Answer 3

Perhaps this more detailed explaination may help to substantiate the above two arguments:

To Darwin, the concept of natural selection was crucial. This was to him, the chief means by which his theory of "common descent with modification", more commonly known as evolution, could be brought about.

Research by Peter and Rosemary Grant (from 1873 to date) discovered that climatic changes which affected the amount of food available, caused the beak size of the average medium ground finch to enlarge by 4%. The beak size shrank by 2.5% when the reverse climatic changes occurs - all these happened within a decade.

They also found that male cactus finches mated with female ground finches to produce perfectly healthy and fertile hybrids. The implication is that these birds belonged to one species. While natural selection affected the distribution of the birds in the environment, it had not led to a completely new species.

Natural selection does occur - but it involves genes which must already be present. It also decreases biological diversity since only the more adaptable phenotypes survive. In contrast, Darwinian evolution speaks of an increase in biological diversity from single organisms.