Explain how polar bears can't adapt to climate change?

I think that the point that rgiddens is making is that the brown bears that became polar bears did so through finding a niche similar to their last one but located in a new geographical position. It takes many more generations to adapt to an entirely new niche, e.g. to an entirely new food source, as the seals that polar bears often depend on from sea ice. As your own article states, it took several thousands of years for "polar bear" teeth to actually come in, which indicates a very long process of adaptation to a new source of food or method of hunting.

Conversely, summer sea ice could disappear within the century. That is enough time to find a new niche similar to their old one (but where?), but not enough to adapt to a new temperature range, climate, habitat, food source, so on. To echo rgiddens, "neither can survive in each others' ecological niche for any lengthy period of time."

>>>Polar Bears adapting.

To a new zoo.

"The brothers, who were born at the Denver Zoo and arrived in Pittsburgh in June, will be 2 years old Friday."

That is NOT the same as trying to fit into a new niche.

First things first, evolution is change in the genetic traits of a species that occurs over successive generations, not neccessarily one.

Individual animals in a scpecie do not adapt, the entire species adapts to changes in the environment. This occurs because the individuals that are not suited to the environment cannot survive and therefore only the ones which are suited breed and pass on their genes and hence the species adapt. This is called natural selection and is a cause of evolution.

Polar bears cannot adapt to the warmer temperatures that climate change causes because there is nowhere near enough time for this process to take place. Female polar bears only reproduce every two and a half years and the earth's temperature is set to rise 1.1 to 6.4 °C (2.0 to 11.5 °F) in the next 100 years, there is not much hope for the survival of the species.

From the research I have done, it seems that the brown bear didn't 'adapt' to the last ice age as such but actually migrated to areas with warmer climates.

Also, an interesting fact is because polar bears and brown bears can breed to produce fertile young, they are still technically that same species. However, they are often classified as different as neither can survive in each others' ecological niche for any lengthy period of time.

First things first, evolution is change in the genetic traits of a species that occurs over successive generations, not neccessarily one.

Individual animals in a scpecie do not adapt, the entire species adapts to changes in the environment. This occurs because the individuals that are not suited to the environment cannot survive and therefore only the ones which are suited breed and pass on their genes and hence the species adapt. This is called natural selection and is a cause of evolution.

Polar bears cannot adapt to the warmer temperatures that climate change causes because there is nowhere near enough time for this process to take place. Female polar bears only reproduce every two and a half years and the earth's temperature is set to rise 1.1 to 6.4 °C (2.0 to 11.5 °F) in the next 100 years, there is not much hope for the survival of the species.

From the research I have done, it seems that the brown bear didn't 'adapt' to the last ice age as such but actually migrated to areas with warmer climates.

Also, an interesting fact is because polar bears and brown bears can breed to produce fertile young, they are still technically that same species. However, they are often classified as different as neither can survive in each others' ecological niche for any lengthy period of time.

I'm at a loss, you seem to have several statements here that are just pure fiction.

What is known of the last half dozen ice ages is that they took thousands of years to happen.

at least twice as long as it takes to come out of an ice age something like 20,000 years, a little longer than a meal. Polar Bears evolved around 150,000 years ago, that would be in the final stages of the previous ice age not the last one. Polar Bears are quite intelligent and adaptable, but so far that adaption has been to try and get food from human settlements, but our response has been to relocate them and if the return to put them down.

Also not sure what your link is meant to prove, it states there are 22-27,000 thousand PB's in the wild so they are not in trouble, strange that in the wild there are more than double that number of Lions and nobody questions that they are in trouble as a species.

lets say that they did adapt to the ice from years ago, but then something known as global warming starts to melt the ice or the bears shelters which is in the pole where a few large glaciers are turning to water, then the bears wouldnt adapt to anything else 'cause theyre used to cold and not heated areas or climates, which is similar to a tortoise for example with a hot dry desert then it would last with the species.

Do you suggest that brown bears evolved into polar bears between meals? Amazing.

*Added* - Adaptation is a form of evolution. An animal or plant does not simply change its diet from one meal to the next without some consequences. Bears do have a wide range of dietary foods, but they are not unlimited in what they can survive on for food. Polar bears depend on seals for a large part of their high energy food source. They could probably eat their fill of field mice but they would still not take in all the fat and proteins that seals provide them to get through the winter months.

Polar bears are not good at hunting while swimming. They are only good at hunting on land. If a polar bear mother has trouble feeding herself before hibernating, what chance do the polar bear cubs have?

Bears eat beets battlestar gallactica

they only lives in cool places and donot survive other places