The existing species concept called into question

Bears breed across species borders - 'Species' is a man made word


Excerpt: "Pizzly, grolars or "capuccino bears" are common names of the offspring resulting from the mating of grizzly bears (Ursus arctos) and polar bears (Ursus maritimus). "Such hybrids among bears are not as rare as we have hitherto assumed," says Prof. Dr. Axel Janke of the Senckenberg Biodiversity and Climate Research Center in Frankfurt. In a large-scale analysis, a team of scientists led by the German evolutionary geneticist has sequenced six complete bear genomes. Each genome is about 2.5 billion base pairs large. "With these new data of the sun bear, sloth bear, Asiatic black bear and spectacled bear, we now have the genomes of all known bear species," adds Janke.

It has previously been assumed that the number of hybrids between polar and brown bears is increasing due to climate change, because brown bears invade northern regions and polar bears move onto the sea ice later than usual. The new results show however that an abundant flow of genes among different bear species occurred to a good deal in the past. Hybrids are thus not necessarily linked to climate change. "Bears can form hybrids in different combinations," explains Janke, and adds: "We knew this from zoos. In the wild, so far this was only observed for polar bears and brown bear as well as Asiatic black and sun bear."

The new genomic data also show that there must have even been gene flow between the polar and sun bears. However, the two species live in geographically completely distinct areas and thus have never met.

The detected gene flow among bears also questions the basic biological concept of a species. The biological species definition assumes that different species cannot produce offspring in the wild or that hybrid offspring are sterile. The best-known example of this is the mule -- a hybrid between a horse and a donkey. However, it has been observed that grolars, the hybrids between polar and grizzly bears, are often fertile. Janke: "We have to ask ourselves: Does the species concept still hold true, given there is evidence of gene flow not only in bears, but also in other animals?"

My comment: Why are they surprised after observing Bear variation which is based on epigenetic control of gene expression? Bears are just adapted to different environments, different diet and climate and that's why they look a bit different. But actually they are the same kind. That's why they are able to breed and get fertile offspring.

'Species' is a pseudoscientific term used for maintaining evolutionary illusions. Adaptation to different diets and climate leads to loss of biological information due to genetic mutations. An intensive loss of information might cause even chromosome loss and this can affect the mating willingness and even cause chromosomal barriers for breeding. Different looking bears are not willing to mate in the wild due to control of pheromones but in captivity we can observe interesting cases of hybridization. For example, the Red Muntjac has the lowest diploid chromosomal number in mammals (2n = 6 for females and 7 for males) whereas Reeves' Muntjac has 2n = 46. But still these two 'species' can produce viable F1 hybrids in captivity.

Everything points to Biblical creation and rapid variation of kinds. Don't get misled.