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I thought they were two species!

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“It actually is a hybrid,” said Judy McLinton, a spokeswoman for the Northwest Territories’ environment and natural resources department in Yellowknife.

Jim Martell, 65, who paid 50,000 Canadian dollars (45,000 US dollars) to hunt Polar bears, shot the animal, described by local media as a “pizzly”, a “grolar bear”, or Martell’s favorite, a “polargrizz” on April 16.

The Idaho native told The National Post: “Everybody thought it was a Polar bear, and then they started looking more and more and they seen other features that resembled some of a Grizzly as well.”

The bear had thick, creamy white fur, typical of Polar bears, but its long claws, humped back and shallow face, as well as brown patches around its eyes, nose, back and on one foot are Grizzly traits.

Geneticists have linked the two species. They believe Grizzly bears ventured north some 250,000 years ago to hunt seals and that their fur turned white over time. Thus, the Polar bear was born.

Odd couples have produced mixed offspring in captivity.

But this is the first discovery of this mixed breed in the wild, officials said.

The two species mate at different times of the year and inhabit vastly different regions — one lives on Arctic ice floes, the other in forests.


http://www.breitbart.com/news/na/060510183011.d5c43drf.html

Does this discovery eliminate the need for a LCA for the polar and grizzly bears? I wonder how many more LCA’s can be eliminated? Is the evolutionary tree getting ‘shafted’ here somehow?

Comments

I'd be interested in knowing if there are any others out there. The two different species of Ursus have different behaviorial traits and adaptations. Anyone know about any data analysis on this animal?

Guerrero_Ink
May 15, 2006
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bFast:

"It would seem that lions and tigers are the same species."

Lions and tigers are definitely not the same species. Neither male nor female ligers are reproductively fertile.

How many ligers have been raised to maturity and tested for sterility that you feel so confident they are sterile instead of just having arbitrarily less chance of successful conception than their parents? I sincerly doubt enough individual ligers have been tested to reach any reasonably certain conclusions aside from saying none so far have demonstrated the ability to conceive. But feel free to provide data that proves me wrong. -ds Jasper
May 12, 2006
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PaV: "Darwinists are mistaken with other putative designations of species, then Darwinism becomes even more suspect." Check out the following links: http://www.greenapple.com/~jorp/amzanim/crossesa.htm It would seem that wolves, coyotes and jackels are all one species. It would seem that bison and cattle are the same species. It would seem that lions and tigers are the same species. It would seem that african and indian elephants are the same species. However, let me suggest that biology has effectively abandoned that classic definition of a species -- defined by it's ability to produce fertile offspring. A new definition, describes as groups which remain genetically isolated, has taken its place. Because of the new definition, polar and grizzly bears get their own species designation. So do wolves and coyotes. The advantage of this approach is that a whole lot more biologists get the privelage of naming a species. Ain't that exciting? BTW, by the classic definition the glapagos finches are not a separate species. They are quite capable of mating with mainland finches.bFast
May 12, 2006
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wb4: "While the two species can still interbreed, which is not surprising given how recently they diverged, modern polar bears show adaptations to the cold, icy environment, such as black skin to absorb sunlight; long, hollow hairs for insulation; a bow-legged walk for better balance; and fur on the soles of the feet for better traction." We know that all dog VARIETIES breed with one another. They are very diverse--chihuahuas versus Great Danes; they are the product of artificial selection; and they all represent the same species. Africans are homo sapiens. Germans are homo sapiens. Germans are well suited to cold climates. Africans are suited to hot climates. But they are the SAME SPECIES. My argument--and it still stands--is the neo-Darwinists glibly say, "Oh, this is a separate species from that one over there. And (much like you've argued) they're adapted to their environments JUST LIKE DARWIN "predicted"." Yet the reality is, that most of the time they really don't know what they're talking about. Added to this point is that the 'lumping' together of grizzlies and polar bears narrows the apparent 'plasticity' that Darwinism assumes exists in animals. If Darwinists are mistaken with other putative designations of species, then Darwinism becomes even more suspect.PaV
May 11, 2006
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Interesting, this low latitude Grizzly or high lattitude Polar Bear. If Grizzlies wandered North and stayed I'd suppose only those producing white hairs would survive. Here could be an example where natural selection has filtered out the dark haired ones. Adaptation at work shifting gene frequency in populations by natural selection. The further North they went the harder it would be to capture prey with darker hair. I wonder if anyone has done a graph of hair coloration vs environment coloring? Even color vs latitude? Neo-Darwinism and Last Common Ancestor. I wonder if its misleading to think of LCAs? If we think in a neo-Darwinian mode for a while, where all biological novelty arises from Randon Mutations RMs (generating events) and Naturan Selection NS (filtering events). From some ancestor of the Grizzly which was not a Grizzly, there was a sequence of RMs and some NS over time leading to the Grizzly's in the Rockies. The RMs acted on the germ line genomes in the sequence. Between any two animals in this breeding sequence there could be 0,1,2 or more differences in their genomes caused by mutations. All passed for a while at least their fitness test. They survived long enough to breed. Now think about the sequence of animals involved. I would guess the mutations from breeding pair to offspring were few, meaning there would have been a more or less closely related chain of animals from the ancestor of the Grizzly we started with to the modern Grizzly. If the neo-Darwinian paradigm is vaguely correct we should see chains of relatedness between all life. Currently we see great gaps everywhere. So I'd suggest, when you are working in a neo-Darwinian mode you think of chains of closely related life forms separated by at least one mutation rather than LCAs. The notion of a LCA seems to me to obscure what neo-Darwinism predicts: closely related chains of life forms separated by mutation in germ line genomes. In neo-Darwinian space your LCA would likely be the animal next to you sharing the same environment as you and just as fit as you.RussellBelding
May 10, 2006
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Geographic, behavioral, or reproductive isolation does not a species make. This example with bears is just like Chihuahuas, Great Danes, and wolves all being the same species. The code of their genomes is compatible, and cross fertilization will produce fertile offspring among them even if it is unlikely, or impossible, that they would mate by themselves. The same can be said for the various "species" of Darwin's finches in the Galapagos. They are all the same species in that they have compatible genomes. Selection has led to different gene frequencies that create different behaviors and physical characteristics in these birds, but their genome is the same, and actually under certain conditions they all will interbreed and produce fertile offspring. Darwin’s finches, which by legend is what led Darwin to his theory, do not exhibit evolution at all. What we see is selection acting to promote or suppress the frequency of pre-existing genes within a the gene pool of a single species. Stu Harris www.theidbookstore.comStuartHarris
May 10, 2006
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PaV, but isn't this exactly the sort of situation that the ToE would predict? Here we have two populations of bears that began to inhabit separate environments (forest vs. arctic ice sheets) about 250,000 years ago. While the two species can still interbreed, which is not surprising given how recently they diverged, modern polar bears show adaptations to the cold, icy environment, such as black skin to absorb sunlight; long, hollow hairs for insulation; a bow-legged walk for better balance; and fur on the soles of the feet for better traction.

wb4
May 10, 2006
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I don't know, bFast...250,000 years is a tiny fraction of the amount of time since the dinosaurs went extinct 65 mya, after which much of the diversification in mammals took place. 250,000 years is about 0.38% of that time.

It is hard to grasp the time scales involved. To get a gut feeling for it, it helps to translate it into something more familiar. Here's an analogy that I find helpful. First, turn the years into distance so that 1 mm represents 1 year. (If you think easier in English units than metric, 1 mm is about 1/25 inches.) Then 65 million years translates to 65 kilometers (about 40 miles). 250,000 years, by contrast, translates to just 250 meters (about 820 feet).

When really large distances are involved, I like to take it a step further and figure how long it would take to drive that distance at 65 miles / hour. 65 million years, at 1 mm per year, would take about 37 minutes to drive. 250,000 years would take just 8.6 seconds.

wb4
May 10, 2006
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I've corrected the original post from LCD to LCA, as it should have been.PaV
May 10, 2006
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OOOOps. Thanks Charlie, you're right. LCA.PaV
May 10, 2006
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LCD is "last common descendant". In the Darwinian "branching" paradigm, some 'species' gave rise to these two other 'species' of bear (a 'proto'-bear). But, of course, the polar and grizzly don't really seem to be two species after all. Yet that's not a problem for Darwinists since all they'll do is come up with a definition that serves their purpose, irrespective of its truth value.PaV
May 10, 2006
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Perhaps LCD is a slip and PaV meant last common ancestor?Charlie
May 10, 2006
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These two "species" of bears have been separated from each other by 250,000 years, yet true speciation truly hasn't occurred. It would appear that there is no more real difference between the grizzly and the polar bear then there is between a collie and a husky. It would seem that simple genetic isolation isn't adequate to produce speciation in advanced mammals even in hundreds of thousands of years. This seems to be a poor fit to the theory of RM+NS being the creator of speciation, let alone the higher taxa. By the way what is an "LCD" in this context?bFast
May 10, 2006
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