Breeders of pedigreed cats sometimes create new cat breeds by artificial selection. Why isn't this evolution?
86391
These new breeds of cats are not new species. All cats still belong to Felix domesticus, and can interbreed a Persian to a Siamese etc... If the breeder was to create a cat that could no longer breed with another cat, but only its new "breed" to create a viable offspring, than I believe it would be considered evolution.
605018
Cheetahs aren't clones.  They are, however, genetically very similar to each other, more so than most other species.  In fact, there is so little variation among cheetahs that tissue can be grafted from one cheetah to any other cheetah and they won't reject it, even without the immunosupressent drugs given to human transplant patients.  But there is a little genetic variation.\n\nThe lack of genetic variability among cheetahs is the result of something that biologists refer to as the founders effect.  This occurs as the result of a population bottleneck, when most of the population disappears as the result of a natural disaster, or a change in environmental conditions that most individuals are not able to survive.  This is what happened to cheetahs at some point in relatively recent history.  The cheetah population was reduced to just a handful of individuals.\n\nOver time, the species either dies out entirely, or makes a comeback.  In the case of cheetahs, they came back.  However, all the cheetahs in existences today decended from this small number of individuals several generations ago.  That means that all modern cheetahs are closely related.  It's sort of like they're all cousins.  That's why there is so little genetic variation among cheetahs.\n\nOf course, there's also the theory that it's all a big government cover-up :)
1091461
No, they cannot. Raccoons and cats are not even remotely related. It sounds as if you have brindle cats in your yard..markings that resemble a raccoon, but no cross breeding here.
165499
It's instinctual.  In the natural world, a cat would be a dog's lunch.
119623
In nature, living things evolve through changes in their DNA. In an animal like a chicken, DNA from a male sperm cell and a female ovum meet and combine to form a zygote -- the first cell of a new baby chicken. This first cell divides innumerable times to form all of the cells of the complete animal. In any animal, every cell contains exactly the same DNA, and that DNA comes from the zygote. \n\nChickens evolved from non-chickens through small changes caused by the mixing of male and female DNA or by mutations to the DNA that produced the zygote. These changes and mutations only have an effect at the point where a new zygote is created. That is, two non-chickens mated and the DNA in their new zygote contained the mutation(s) that produced the first true chicken. That one zygote cell divided to produce the first true chicken. \n\nPrior to that first true chicken zygote, there were only non-chickens. The zygote cell is the only place where DNA mutations could produce a new animal, and the zygote cell is housed in the chicken's egg. So, the egg must have come first.\n\nVirginia Kelly\n\nTo be ...
101735
Natural selection is a mechanism of evolution which involves the "interaction" with environment. The fitness of an organism to their environment depends on it's phenotype, not genotype, since genotype doesn't "interact" with environment.\n\nAs for example, black heterozygote moth which lives in a polluted area (black sky), have the same fitness as black homozygote moth at the same condition.They're harder to be noticed by their predator, hence have a better chance to survive compared to those white moths. \nBoth of the moths have different genotype, but since the two genotypes are translated into one same phenotypes, it doesn't affect their fitness.\n\nAnd as conclusion, natural selection only works on phenotypes, since only phenotypes that have direct "interaction" to the environment.
213472
Good question,  actually I got tested on this very subject in my Intro to Environment class.\n\nOne thing that can and does happen is the bottle neck sydrom.  That is, a species, take the cheetah starts out with a large amount of genetic variability (lots of different breeding animals), but over time, through loss of habitat, change in climate or introduction of a new disease or preditor (in the case of cheetahs, over hunting by humans), genetic isolation and competetion from other preditors or loss of prey will induce die back.  The strongest, most adaptable animals survive, but after awhile, the lack of numbers takes a toll on a genetic population.  There are less and less animals to breed with, so they end up breeding with brothers, sisters and mothers. In the case of the cheetah, bottlenecking has happened many times, but they recovered (which might not happen this time). This can wreak havok, since one good disease will wipe out the specieis (especially in the wild) in the long run.
619140
There is no reason for natural selection for most traits that differentiate most dog breeds. They have been bred. This is human selection, not natural selection. The breeder decides what traits he likes and controls the matings to favor this trait.
245236
Horses have genes, and those genes determine what the horse will look like.  If there wasn't genetic variation, all the horses would look the same.
1048996
Hey Bud, have you ever taken a class in evolution?\n\n"You're logic is flawed. There is plenty of evidence to show small adaptations within a species. These small variations enable animals to adapt to their environments.\n\nBut to go from that to changes from one species to another is quite a blind leap of faith and poor science as well. " Poor science according to who?\n\nHow many small variations does it take to turn one species into another?  A few small genetic variations make slight changes in organisms.... a few more make more changes... a few more make even more changes, and eventually enough of these little changes of added up so that the 2 groups of organisms are no longer able to interbreed. Thus, a new species - evolution at work.\n\nPoor science is when people who have not studied evolution try to disprove it. You come up with some pretty wacky ideas. Evolution is not something that animals do on purpose to improve. There is no plan, purpose, or goal to evolution. An animal that adapts to his environment (after he is already born) like your example is NOT evolution. Evolution affects populations, not individuals, and it does not 'occur' after an organism is born. Evolution only occurs when the gene frequency in the population is changed, through natural selection, random mutation, drift, etc.
938235
First, I assume you know when you say "a dog into a cat" that evolution is not about an individual (a specific dog) changing ... it's *always* about an entire population of *many* individuals changing over many generations.\n\nSecond, remember the definition of 'species'.  Two individuals are considered members of the same species if they are genetically compatible enough to interbreed.   So dogs could, through natural selection, change to become more "cat-like" ... but it would be impossible for dogs ever to be able to interbreed with cats (their chromosomes are just too incompatible).\n\nThird, natural selection never moves in the same exact direction twice.  Dogs are the result of (1) certain genetic accidents and (2) certain environments in the history of evolution.  Cats are the result of *different* genetic accidents, in *different* environments.  Even if dogs today were subjected to millions of years of exactly the same environments that caused cats ... it is still impossible that the dogs would recreate the same genetic accidents.  And furthermore, dogs would have to *lose* a lot of their "dog chromosomes" to become genetically compatible with cats.\n\nIn summary, natural selection can cause a single species to split into two (go from being genetically compatible to genetically incompatible for breeding).  But it can never cause members of two separate species (i.e. genetically incompatible for breeding) to become one species (i.e. capable of interbreeding).
664367
sure, the best examples would be ants, bees, and naked mole rats, they all are animals that live in very tight family groups, they have different specialized individuals within each hive or nest, ranging from a queen whos sole job is to reproduce, then there are workers, defenders, and drones to fertilize the female, oddly most of these animals are extremely inbred because they do not go out of their hive in order to find mates, most mates are usually sons of the queen, thus the gene pool never gets expanded, but this is just an example becuase most animals have some social order that seperates the strong from the weak
111422
Come on, you've got to do SOME leg work here.  Those are huge subject areas.  Where would we start?\n\nOK, Darwin: Natural selection acts on random variation.\n\nLamark: Acquired characteristics can be passed on to the next generation.
580432
The problem that creations have with evolution is that they think of evolution as a ladder. You need to view it as a tree, each branch as smaller branches that are similar.\nFor example dogs and wolves are very similar. \nLions, tigers, and house cats are similar.\nall animals come from a single organism.\n\nDidn't you learn this in biology class???
805618
u want to breed with a kitten?
918371
c is the right answer.\n\nA makes no sense in relation to the question\nB natural selection has a bit of randomness in it of course but is basically not random. I mean, the fastest critter in the herd may have had an unlucky day and so he will not procreate, oops. But otherwise, the slowest are intentionally selected by the lion and that is never random.\nD just isn't true, plenty of proof there.
395275
In nature, living things evolve through changes in their DNA. In an animal like a chicken, DNA from a male sperm cell and a female ovum meet and combine to form a zygote -- the first cell of a new baby chicken. This first cell divides innumerable times to form all of the cells of the complete animal. In any animal, every cell contains exactly the same DNA, and that DNA comes from the zygote.\n\nChickens evolved from non-chickens through small changes caused by the mixing of male and female DNA or by mutations to the DNA that produced the zygote. These changes and mutations only have an effect at the point where a new zygote is created. That is, two non-chickens mated and the DNA in their new zygote contained the mutation(s) that produced the first true chicken. That one zygote cell divided to produce the first true chicken.\n\nPrior to that first true chicken zygote, there were only non-chickens. The zygote cell is the only place where DNA mutations could produce a new animal, and the zygote cell is housed in the chicken's egg. So, the egg must have come first.