Essay:Observed instances of speciation
Many creationists often deny that speciation has ever been observed, either in a controlled environment such as the laboratory or in the natural world. But first, we have to define what is a "species."
Definition of species
The traditional definition of a species is that if an organism has the potential to interbreed, or actually has interbred in the wild, it is a species. There is often wild variation within a species, dogs may look radically different, but since they can interbreed, they are a species. This does have its problems though, especially for asexually reproducing species like bacteria or protozoans, given the fact that they reproduce by splitting into two, or in some cases spores that get distributed through the wind as is the case with fungi, they don't interbreed, they replicate themselves, the offspring of a bacterium is an exact clone of that bacterium. There is also the problem of two closely related species interbreeding, if they are classified as different species, but can still interbreed, aren't they the same species? Take for example the coydog, a hybrid of the coyote and dog, the two are supposed to be different species, in this case, Canis latrans and Canis familiaris, they can interbreed, and are even fertile.
However, there is a partial solution to the interbreeding species problem, it's called "sterility" of an offspring, for example, a lion and tiger can hybridize, and the end product of their sex is the liger, but the liger is sterile, meaning it cannot reproduce, thus creating a dead end. Some species can arise as a result of hybridization, known in biological nomenclature as a "nothospecies", one natural hybrid thought to have formed at the end of the last ice age is Saxifraga osloenis.
A better definition of a species would be two distinct populations from each other that may be able to produce fertile hybrids, but for a multitude of different reasons don't usually interbreed.
Observed instances of speciation
- Kew Primrose: The Kew Primrose arose as a result of hybridization of two primroses back in 1912, with most offspring being infertile of the experimental primroses, but a few produced fertile offspring, thus creating a new species.
- York grounsel: The York groundsel was first discovered in a tiny area of York in '97, this species was confirmed through DNA testing to be the first new species to evolve in Britain in over 50 years! This "scruffy little weed" spread like wildfire around the surrounding area, but the ecologist who first found it thought to not enact any conservation measures and to just "let nature run its course". He wanted to see if the weed could survive the ruthless struggle for life that is natural selection. Given this was in '97, I am not aware of the current state of this "scruffy little weed".
- Red Wolf: The American red wolf has DNA in between that of coyotes and wolves, and is thus thought (with controversy) to be a hybrid between coyotes and wolves, yet the red wolf would qualify as a species since it any offspring when paired with coyotes or wolves it will potentially produce are always infertile.
- The clymene dolphin is thought to be a hybrid between the spinner dolphin and striped dolphin, it was known in older texts as the "short-snouted spinner dolphin".
- A population of "genetically indistinguishable microbes" divide, despite "sharing same habitat." This could be evidence of a controversial form of speciation called "sympatric speciation," in which a population divides into two or more species despite having no geographical or mechanical barriers separating the two.
- Or Canis lupus familiaris, depends on the taxonomist
- See the wikipedia article on the subject
- This bypasses some of the problems mentioned above, such as the fertile offspring question, but doesn't account for all questions raised by properly defining a "species," and only works in general for sexually reproducing organisms, asexually reproducing organisms are still left unaccounted for.