Answer by Diane Eager
A ring species is where a species has spread over a large geographical range around an uninhabitable zone, forming a ring shape with ends of the range overlapping one another. Throughout the range neighbouring populations can interbreed but not where the two ends of the range overlap.
The classic examples of “ring species” used in text books are the Herring Gulls which are found across the sub-arctic regions of the northern hemisphere, and the Ensatina salamanders of the western USA. A more recent example is the Asian Greenish Warbler which spreads around the Himalayas, and where we find that two northern populations overlap but do not interbreed, but the only significant difference seems to be they have different songs.
The argument for using ring species as evidence for evolution is that as the species such as Herring Gulls spread out over their large geographical range from UK to Greenland, to Alaska, and back around to Scandinavia the subgroups of the species at opposite ends of the range no longer breed with one another, therefore they are becoming new species and this is classic evolution. In the case of Herring Gulls they are given different species names: Herring Gulls Larus argentatus and Lesser Black-backed Gull Larus fuscus.
The flaw in the argument is that in every case, the creatures observed so far at each end of the ring are still gulls, salamanders or warblers. There has been no change from one kind of creature to another. There may no longer be able to breed due to some mutational variation or learned behaviour such as mating songs, but these minor factors have not yet changed them from one kind to another. The faith in the argument is that given a few million more years, the eastern and western varieties will be so different they won’t even be gulls.
If the you define a species as a group of living things that breed with one another, but not with those that are a different species, then the splitting of a large and varied group of living creatures into two or more smaller and less varied groups is technically the origin of species. However, evolution from single celled creatures to man, requires that creatures be able to change into something different, rather than just becoming a subgroup or variation of what they already are. The biggest mistake that evolutionists, from Darwin onwards, have made is to equate the origin of species, e.g. Herring Gulls and Lesser Black-backed Gulls, with the origin of separate kinds, e.g. gulls and ducks.
Darwin may have written about the origin of species, but Genesis does not – it tells us God created living things according to their kinds. Within the kinds there can be much variation, e.g. variations in pigmentation in gulls and salamanders due to gene reshuffling as well as degenerate variations which have been added by mutations. However, this does not change them from one kind to another. Some of these mechanisms may indeed result in some members of the same kind no longer breeding with each other, i.e. reproductive isolation, but this is not evolution. It simply reduces the pool of potential mates for each sub-group, reduces the gene pool within any group, and is probably the first step towards extinction. It has never been observed to produce Darwinian evolution and indeed can never make such creatures into a new kind.
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