Endlers.nl - What is a species; remarks on the renaming of ELB to Poecilia wingei
Species mean more to humans than they do to Nature. Species boundaries are artifical constructs that exist to make life quantifiable and classifiable. The very fact that Endlers and "regular" guppies interbreed so easily reinforces this point, and whatever we call an ELB, from the point of view of a guppy, it's close enough to be seen as a potential mate.
When animals like fish receive a name in a scientific paper, this is merely an opinion. Creating a scientific name doesn't "do" anything to the animal, and often other scientists will disagree with the the new name. Scientists will be looking for reasons to squash the "new" species name. In the case of the ELB there are arguments over the methods used, the regular guppies that the comparisons were made with, the form of the gonopodium, etc. etc..
The classical definition of species ( By definition it applies only to organisms which reproduce sexually...) was proposed by Ernst Mayr in 1942, defining it as reproductively isolated groups of organisms. In his book Systematics and the Origin of Species (1942) he wrote that a species is not just a group of morphologically similar individuals, but a group that can breed only among themselves, excluding all others.
This is known as the "biological species definition" - An animal is a member of that species if, mated to another member of the species, they produce offpring which are in turn capable of producing offspring of that species.
The offspring of a horse and donkey, or a tiger and lion, goat and sheep, are sterile (almost all the time), because horses and donkeys, and tigers and lions, etc. are members of different species.
( That makes this offspring the REAL hybrids...not the crosses between guppy and ELB, that are NO hybrids in the classical sense..)
SMS "HOTMAIL" naar 3010 en ontvang gratis de juiste instellingen voor Hotmail op je mobiele telefoon.