The cheetah is the fastest animal on earth. Its skeleton is lighter than other big cats; its legs are long and slim, like the legs of a greyhound. Its heart, lungs, kidneys, and nasal passages are enlarged, allowing its breathing to jump from 60 per minute at rest to 150 bpm during a chase. No wonder it can't be outrun (although can be outlasted).

Cheetahs are unique because they combine physical traits of two distinctly different animal families: dogs and cats. They belong to the family of cats, but they look like long-legged dogs. They sit and hunt like dogs. They can only partially retract their claws, like dogs instead of cats. Their paws are thick and hard like dogs. They contract diseases that only dogs suffer from. The light-colored fur on their body is like the fur of a shorthaired dog. However, to climb trees they use the first claw on their front paws in the same way that cats do. In addition to their dog only diseases, they also get cat only ones. And the black spots on their bodies are, inexplicably, the texture of cat’s fur.

But there's more.
Genetic tests have been done on them and the surprising result was that in the 50 specimens tested, they were all, every one genetically identical with all the others! This means the skin or internal organs of any of the thousands of cheetahs in the world could be switched with the organs of any other cheetah and not be rejected. The only other place such physical homogeneity is seen is in rats and other animals that have been genetically altered in labs.


Would anybody care to shed some light on the cheetahs' genetic uniformity?

Cheetahs are not the fastest animals on Earth. I believe that honour goes to the Perergrine Falcon, but I'm not sure.

Cheetahs are all, or mostly, related so closely now because there are very few left. Breeding populations are very small.

I think she may have meant that the cheetah is the fastest runner on earth.

All the cheetahs are completely identical genetically? Do you have a source for this? I would like to read more.

It's not that cheetahs are all identical, just that with such a limited gene pool they are becoming very inbred.

Originally posted by Circe

Genetic tests have been done on them and the surprising result was that in the 50 specimens tested, they were all, every one genetically identical with all the others!

Should I not be taking this as written?

I have seen it stated, too, that cheetahs are so inbred that they are, for all practical purposes, genetically identical. A sad state of affairs for the species. Not sure where you'd find a link on that, but you might start with Nat Geo. I'd bet you could find something about it there.

My bio teacher was talking about the cheetahs and he said scientists are looking for a cat very similiar to the cheetah so that we can still have something that looks like the cheetah of today. They will breed the two species. Genetically it will be a different animal but the phenotypes will be relatively the same.

All the cheetahs are completely identical genetically? Do you have a source for this? I would like to read more.

Well, there's this website here (http://lynx.uio.no/jon/lynx/cheetahgenes.html)
where Stephen J.O'Brien of the National Cancer Institute states:

Before conducting genetic studies for Craig Packer's Lion project, I examined the genetic history of the Cheetah, whose range once spanned the globe. I was amazed to find that every one of today's 20,000 Cheetahs is genetically almost identical
(source: National Geographic)


Idle Mind - I'm a female ;)

Also If the cheetah are so closely related because there aren't many of them left and so they have to inbreed, why, for example, the siberian tigers (whose population is much smaller) aren't similarily genetically uniform? Why of all the "almost exinct" species only cheetah are so "special"?

I apologize If these are dumb questions. I probably should have done more research :rolleyes:

First of all, I must apologise for calling you a 'he'...I haven't been around long enough to know who everyone is yet. Sorry about that.

I can offer a possible explanation for the tiger's relative lack of genetic closeness. Keep in mind that this is only a guess.

It may have to do with the geographic range that the tigers inhabit compared to that of the cheetah. Asia and Siberia are much larger places than the plains of Africa, and the fact that there are fewer numbers spread out over a larger area may play a part. There could possibly be pockets of tigers that have an almost identical genetic make-up, but as a whole they will vary more. There are so many different climates and environmental factors that the tigers encounter. Whereas the cheetahs are in a relatively small area, all with a very similar climate, vegetation, prey etc. Not much need for adaptation there, when they are very specialized for what they do already.

However, I feel as though I am starting to repeat myself, so I will stop there. Just some thoughts.

*edit: Thanks for the link.

the other option would be that cheetahs went through a genetic bottleneck not so long ago.

Did you get that off the link that Circe posted? It says that almost verbatim on the site.

you mean they evolved recently?

that would be VERY interesting in proving the evolution theory or checking the contamination theory

So the evidence seems clear that they are very inbred. But why do some scientists think that cheetahs were reduced to a population of less than seven individuals, about 10,000 to 12,000 years ago.

They think less than seven individuals, because it has been shown that if a population is reduced to seven individuals and then expands quickly, the offspring still retain about 95% of their genetic variability. But cheetahs have almost zero genetic variability - there's hardly any difference between them.
More (http://www.abc.net.au/science/k2/moments/s40791.htm)

Looks like without help from genetic manipulation, like breeding with other cats mentioned before, they're on the way out, just a matter of time.

sad, they are such a beautiful creature

think we can engernear a virus to save them?

that would manipulate the gene slightly wouldnt it?

I don't know if that would help at all though. It is theorized that a large portion of our DNA has a viral origin as it is. I don' t see why it would be any different for the Cheetah. And will the alteration be beneficial? I think it would just contribute to the junk DNA, and wouldn't be sufficient in saving the species. Aside from the fact that would be subjecting them to infection, which could have poor results in itself.

i admit i know little about biology and less about genetics

but how does the fact that some of us have blue eyes and some green save the species?

Originally posted by Idle Mind
Did you get that off the link that Circe posted? It says that almost verbatim on the site.

i think it is common knowledge...i don't really have to look up simple things like that.

And I am a lazy reader, hence you often see me apologize for not correctly reading a previous post.

Originally posted by Asguard
i admit i know little about biology and less about genetics

but how does the fact that some of us have blue eyes and some green save the species?


it doesn't necessarily save a species, but it might.

more genetic variety, simply means more possibilities. Variety is the raw building material of evolution. If you have red bricks and brown bricks, you can build both red and brown houses or a mix of them. A storm comes along and only brown houses and the mixed houses prove to be sturdy enough to withstand the storm. But maybe a cold winter will come and red bricks are better heat insulators. Then the red brick houses are better.

Therefore, more variety, more options.

also, our immune system is partly based on genetic information. Some diseases effect some genetic composition, others are unaffected. That's also why there are the problems now with bananas. They are basically all clones, and a single disease is theatening them.

so a fast mutating virus wouldnt help?

if you make it unstable so it changes alot couldnt that go through the whole pop and change them all?

there are chemicals that induce mutations and are used for this purpose in research, but what would probably be most effective for the cheetah is to provide them with plenty of stable environment.

Actually, Asguard,...it is quite an interesting idea of yours. Could we speed up evolution, by creating more mutations? Could we stabilize a population suffering from lack of genetic diversity?


what would we need for this?

*a good mutagen (mutation inducing agent)

*a fairly large population

*and some selection process

anything over 1000 is surpose to be statanable (im not sure about that but i THINK its what i read when i was reading up about the possablility the tassi tiger survives), we can work on the enroment and who knows WHAT the armys of the world can do with virus's and bacteria now

for anyone interested type in 'zebrafish and mutagen' in google if you want to learn more about the use of mutagens in biological research

Hi guys,

Please bear with me just a bit longer ;-)

Someone suggested that a genetic bottleneck accounts for the cheetahs' genetic uniformity.

So let's say that long time ago something horrible happened and almost all the cheetahs died out; there was only a handful left and so they had no choice but to inbreed. Today they share the same gene pool. Fine.

But is it possible that this bottleneck affected only one species, the cheetahs? I can't imagine that any bottleneck can be that selective. And If it did affect other species as well, how come all but cheetahs were able to redevelop their genetic diversity?

Asguard: The only thing is, when a virus is inserted into most eukaryotic cells, it becomes inactive. What good is a fast mutating virus that doesn't replicate. I see what you are getting at though, and it certainly is an intersting thought.

Circe: I won't speak for the others, but I don't mind your questions at all. If I can help in any way, then I will try my best. I just hope that you are satisfied with the answers offered.

About the bottleneck affecting only cheetahs...I think that it likely affected all the species that existed at that particular time. It seems to have happened when a lot of the other large mammals went extinct. With other animals though, they might not have all in the same geographic location after the bottleneck. There could have been pockets of them spread out over a very large area. These small pockets would then inbreed for a few generations and expand in population. Then, if there were two pockets relatively close together, then two of the pockets could join together and begin interbreeding (so long as a speciation event didn't take place, but I don't think 20 or 30 generations is long enough for that). See what I am getting at? Other animals could restore genetic diversity by having varying habitats within the species after the bottleneck.

edit: fixed typos and redundancy

Which animal never loses a game of poker? ;)

Thanks for your time , Idle Mind ;)

See my previous link. Cheetahs were a wide spread animal, throughout several continents. Whatever happened (I've got a theory connection maybe) it wiped out many of them totally, along with other types of mammals. Today's cheetahs are the ones who could just barely rebound from the few survivors in that area. Some other mammals that exist today may have had a larger number, so better diversity. It's an interesting question though, what the current genetic state of life is today, which are plentiful and which are on the borderline.

As for my theory, I hadn't realized there was a minor extinction 10-12,000 years ago. That date eerily coincides with several dates of the supposed destruction of Atlantis, and more importantly, Otto Muck's timeline and theory of an asteroid impact in the Atlantic causing this destruction. Crackpot theory maybe, but there are remnants of craters there, and the timing is about right.

Could have been something else as well...

some human populations are more inbred than others. You could also consider them to have gone through a genetic bottleneck if you like to look at things losely. The people of finland for instance. Many recessive disorders then pop up and have a higher frequency of occurence than normal. Why did it happen in finland, because it was semi-isolated physically. Sometimes cultural isolation is enough for some serious inbreeding.

Circe:

Not a bad question at all about "genetic bottleneck". Humans are thought to have gone thru one about 75k yrs ago. In the cheetah's case, I think it is more recent-- ie, historical times.

An interesting side note: Look on Yahoo Science news today and you will see that scientists in India want to revive the extinct "Indian cheetah" by cloning the cheetahs that inhabit Iran. Cheetah's in Iran today?? How would've thunk it. At any rate, surely those Iranian cheetahs are a different breeding population than their African kin.

John Mace: Cheetahs in Iran today?? Whow would've thunk it. At any rate, surely those Iranian cheetahs are a different breeding population than their African kin.Yes, there are cheetahs in the Mideast. One of the principal tasks assigned to Saluki dogs (a breed of coursing hound of that region) was to hunt cheetahs. It took two of them running in relay, but they could do it. No, nobody wanted to kill the cheetahs, just capture them. In royal times captive-bred, more-or-less tame cheetahs were the prize of the sultan's court.

John Mace - I will check that article on yahoo. Thank you for directing me to it ;)