If polar bears don't have a natural enemy, why did evolution make them white?

Question

If you can't think of an explanation does NOT prove that evolution is not involved. Richard Dawkins in his book "The Blind Watchmaker" gives an explanation. Can you think what it is? (If you read his book, don't cheat!)

I think the common usage of the term "natural" enemy refers to other animals in nature, not to man. We all know that men hunt polar bears for their fur.

Polar Bears ARE white... even if it's their fur that makes them appear that way. Their skin color is irrelevant for the purpose of my question.

Answer 1

I knew it before I read his book: for hunting purposes.

Answer 2

The polar bear does have a natural enemy.....MAN.
Why are they white? Just because they don't have other animal natural enemies at this time does not mean they never did. Also, perhaps they were smaller before. Perhaps there was a natural enemy larger than the polar bear was (or is). There are a lot of potential reasons the polar bear evolved to blend into its habitat. Another reason could be to protect the baby bears.

Not everything is known. For instance...if humans still need protection from the environment...why don't we have fur?

Answer 3

Polar bears do have a natural enemy, and that is Man.. we are still part of the natural world. In any case they are not white to camoflage from enemies they only appear white, which is part of an adaptation to their polar habitat that serves doubly to camoflage their approach from prey. Truth be told polar bears actually aren't even white, their hairs are translucent and hollow and their skin is black. It's an adaptation to the cold climate and habitat they live in. Finally evolution doesn't "make" anything, creatures with favorable mutations are better suited to survive in certain habitats, over time these mutations accumulate because the creatures who possess them are more likely to survive, until you have a creature uniquely suited to it's habitat. It is interesting to note that Black bears can be white, but since it is not a favorable attribute in their present habitat it is a rare occurence. Perhaps if you took some of these bears and introduced them into a habitat where their colour would be favorable you caould get some interesting results.. http://en.wikipedia.org/wiki/Spirit_bear

Answer 4

I hate to break the bad news to you, but they are NOT white. Their fur is color-neutral, actually almost transparent, but *appears* white. The reason, the evolution made it this way, as the fur acts as a *heat pipe* (a spohisticated heat transfer mechanism), it captures sun energy on the outer end of the fur fiber and channels it to the skin, thus keeping the animal warm. White fur fiber could not do that. Just thought I point out the inconsistency in your argument. The animal would NOT have survived had it had white fur, no matter what Dawkins thinks.
"If you can't think of an explanation does NOT prove that evolution is not involved"
a TRIPLE negative, I am dizzy...

Answer 5

My first instinct is that Polar Bears had natural enemies many years ago but these enemies became extinct.

My second thought is that it white Polar Bears were more successful in hunting than their non-white counterparts since they were more camoflagued and could more easily sneak up on their prey.

(In fact, I believe that Leopords have evolved their spots via the same mechanism).

Answer 6

White Polar Bears are God's Chosen Polar Bears.

Answer 7

there's a big dispute why polar bears have white fur, but i believe it is because of the sun. Each strand of fur is like a hollow tube that takes in light, and all that light made the fur white.

Answer 8

Eek, I'm trying to figure out the question. You used a negative three times in one sentence...I'll just go with the initial question.

Here's my guess off the top of my head: They weren't always so large-they did have a natural enemy. They need to blend in to hunt the seals; if they couldn't be sneaky they wouldn't survive well.

Two ideas...how did I do?

Answer 9

It has always been my understanding that the hair on polar bears is actually translucent and not white. Since it is translucent, light refracts and holds the heat from the sunlight in better kind of like your car windshield. So they are not white to avoid predators, they have translucent hair color so that hold in heat from sunlight better so they can live in such cold climate.

Answer 10

Well, you are pretty stupid for an atheist. Evolution doesn't just happen to protect you from natural predators. it also happens to give the animal an advantage as a predator. The polar bear is white so it's prey cannot see it in the snow.

Answer 11

Polar bears are white in order to avoid being seen by prey. No, they didn't intend to be white, it was natural selection. The black ones didn't survive.