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What is the force behind this? Why havn't Humans devloped this?

2007-02-10 00:47:05 · 5 answers · asked by Balance 2 in Science & Mathematics Zoology

5 answers

Evolution of species.

2007-02-13 01:44:19 · answer #1 · answered by Sam 4 · 0 0

Different animals use different methods.

Some have hair/fur markings that helps blend into their surroundings.

Some animals, such as various cuttlefish species, can manipulate their chromatophores to change their overall skin color. These animals have a collection of chromatophores, each of which contains a single pigment. An individual chromatophore is surrounded by a circular muscle that can constrict and expand. When the cuttlefish constricts the muscle, all the pigment is squeezed to the top of the chromatophore. At the top, the cell is flattened out into a wide disc. When the muscle relaxes, the cell returns to its natural shape of a relatively small blob. This blob is much harder to see than the wide disc of the constricted cell. By constricting all the chromatophores with a certain pigment and relaxing all the ones with other pigments, the animal can change the overall color of its body.

Cuttlefish with this ability can generate a wide range of colors and many interesting patterns. By perceiving the color of a backdrop and constricting the right combination of chromatophores, the animal can blend in with all sorts of surroundings. Cuttlefish may also use this ability to communicate with each other. The most famous color-changer, the chameleon, alters its skin color using a similar mechanism, but not usually for camouflaging purposes. Chameleons tend to change their skin color when their mood changes, not when they move into different surroundings.

Some animal species actually change which pigments are in their skin. Nudibranches (a small sea creature) change their coloration by altering their diet. When a nudibranch feeds from a particular sort of coral, its body deposits the pigments from that coral in the skin and outer extensions of the intestines. The pigments show through, and the animal becomes the same color as the coral. Since the coral is not only the creature's food, but also its habitat, the coloration is perfect camouflage. When the creature moves on to a differently colored piece of coral, its body color changes with the new food source. Similarly, some parasite species, such as the fluke, will take on the color of their host, which is also their home.

Many fish species gradually produce different pigments without changing their diet. This works something like seasonal molting in mammals and birds. When the fish changes environments, it receives visual cues of a new surrounding model. Based on this stimulus, it begins to release hormones that change how its body produces pigments. Over time, the fish's coloring changes to match the new surroundings.

Humans have not needed to evolve this, we use out hair, clothes and false colours (make up) to signal readiness to mate and to attract members of the opposite sex.
We do not need to use it for defense as we dont hav any natural enemies.

Maybe if an animal such as bears or velociraptors were the dominant species, we would have developed it, but being at the top of th food chain, we dont really need it.

Its only developed out of necessity.

2007-02-10 00:59:57 · answer #2 · answered by lozzielaws 6 · 1 1

some animals are so amazingly camouflaged i.e. the stick insect, and the leaf bug, that I have a hard time attributing it to 'survival of the fittest' alone-therefore I have come to a conclusion- I am not the only girl around who likes her men hard to get! -As for us humans, our softer side prevailed-we took pity on the poor bald creature and brought him home -now look at us!

2007-02-10 02:21:56 · answer #3 · answered by mistshevious 2 · 0 0

Not all animals use camouflage. For those that do, it evolved as did every other trait. Less well camouflaged animals got eaten or didn't catch enough food.

2007-02-10 00:51:23 · answer #4 · answered by tentofield 7 · 0 0

Evolution. Survival. Both predator and prey animals adapt camouflage. The prey hopes not to be seen and eatten by the predator. The predator hopes not to be seen allowing it to catch prey.

2007-02-10 01:01:14 · answer #5 · answered by Anonymous · 0 1

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