the most fundamental problem of evolution, the origin of species, remains unsolved. Despite centuries of artificial breeding and decades of laboratory experiments, no one has ever observed speciation through variation and selection.
I believe the act of catching speciation in the act is nearly impossible, but to say that no one has ever observed speciation is just being willfully ignorant. I say that it is nearly impossible because of the timescales that are evolutionarily relevant. Remember that our lives, and scientific thought for that matter, is only a blink of an eye in evolutionary time. Therefore, one would not expect to be able to see speciation except in the most rare occurrence.
Another problem with the idea of speciation is that the term and idea of species is somewhat nebulous. A common definition of species is a population of organisms that can interbreed resulting in offspring that are also able to interbreed. This definition has a couple problems. What if only 1% of one population can interbreed with another population? Are those distinct species? What if two populations never mate in the wild due to completely different mating practices, but do mate when pressured to by isolation (e.g. in a lab). Are they different species?
These problems defining species and the extremely long time for speciation events to usually occur allow ID/creation proponents, like Jonathon Wells, to say it has never been observed. They are looking for an example where a population of creatures produces a completely new creature over a short period. This strawman argument will convince the uninformed, but should not deter reasonable individuals.
Here I am going to list a few examples of speciation that we would expect from our understanding of evolution. I want to limit this discussion to historically observed speciation events, the type that Wells believes do not exist. The list of known speciation events is enormous and can’t be easily covered in such a short space (see African ciclids, Darwin’s finches, cave salamanders, etc.).
- Apple maggot fruit fly, R. pomonella. The ancestor of this species of fly mates near hawthorn trees and lays its eggs inside the fruit. However, with the introduction of domestic apples to North America, these flies began using apples instead of the thorn apples. Now, there are two distinct populations of flies. These populations have distinct genetic differences and have varying times until maturity.
- Madeira island house mice. 500 years ago, house mice were introduced to the small island of Madeira off the coast of Africa. Six populations of mice were found containing chromosomal abnormalities that precludes their interbreeding.
- Radish and a cabbage hybrid. Russian biologist Georgii Karpechenko bred a radish and a cabbage to produce fertile offspring that had a completely new morphology. Unfortunately this new form was the leaves of the radish and the roots of the cabbage.