As they were hunted and their habitat destroyed, the genetic variability dropped because of inbreeding
The oldest and most plausibility expanation for
the Cheetah's lack of genetic variability is a
population bottleneck about 10,000 years ago.
There is no evidence of higher infant mortality in Cheetahs due to lack of genetic variation and
this is what you would expect if this lack of
variability had been maintained for many
generations
In theory it makes Cheetah's more vulnerable to
disease - but their behaviour and ecology put
them a low risk of disease.
See Caro's book, Cheetahs of the Serengeti Plains.
But the environment needed by an authentic wild chimp is more or less gone already
Not true - try reading about (or visiting!)
the more remote parts of Zaire, for example.
There may still be 100,000 or more Chimpanzees in the wild. Although the Chimpanzee
has certainly
declined or disappeared over much
of its range due to habitat destruction and hunting for food and the pet/biomedical/entertainment
trade.
Hunting has been a more important factor than
habitat destruction in extinction
of larger terrestial vertebrates in recent centuries
This might extend back to the Pleistocene,
its controversial but some also believe overhunting caused many
large vertebrate extinctions in the Pleistocene.
Suitable habitat still exists many
of these extinct species - e.g. Thylacine,
Toolache Wallaby, Blue Buck, Steller's Sea Cow,
Caribbean Monk Seal, Great Auk, Labrador Duck.
There are extant
species which have no genetic variation - the entire population is a clone.
If you'd prefer a mamalian example, the limited
gneteic variation of the Cheetah is well known -
but people often forget that until recently it
was very successful with a huge range across Africa and Asia - one of the most widespead
of all mammals.
Andrew Taylor
We now know that placental mammals were present in Australia before it was isolated by the breakup of Gondwana ~50 million years ago. Unlike marsupials and monotremes, these placentals did not persist into the present.
The introduction of various placental mammals into Australia in the last 200 years has been a large factor in the extinction of a number of marsupial species. However, these introductions have also a large factor in a similar number of extinctions of Australian placentals - rodent species whose ancestors managed the sea journey from Asia in the last few million years.
Neither data point suggests placental "superiority".
While monotreme diversity is extremely limited, one monotreme, the Short-beaked Echidna, is rather successful - ranging over the entirety of Australia and occupying habitats as diverse as alpine grasslands, desert and tropical rainforests. Few placentals can make such claims.
Slashdot Mirror
The oldest and most plausibility expanation for the Cheetah's lack of genetic variability is a population bottleneck about 10,000 years ago.
There is no evidence of higher infant mortality in Cheetahs due to lack of genetic variation and this is what you would expect if this lack of variability had been maintained for many generations
In theory it makes Cheetah's more vulnerable to disease - but their behaviour and ecology put them a low risk of disease.
See Caro's book, Cheetahs of the Serengeti Plains.
Andrew Taylor
Not true - try reading about (or visiting!) the more remote parts of Zaire, for example.
There may still be 100,000 or more Chimpanzees in the wild. Although the Chimpanzee has certainly declined or disappeared over much of its range due to habitat destruction and hunting for food and the pet/biomedical/entertainment trade.
Andrew Taylor
This might extend back to the Pleistocene, its controversial but some also believe overhunting caused many large vertebrate extinctions in the Pleistocene.
Suitable habitat still exists many of these extinct species - e.g. Thylacine, Toolache Wallaby, Blue Buck, Steller's Sea Cow, Caribbean Monk Seal, Great Auk, Labrador Duck.
Andrew Taylor
There are extant species which have no genetic variation - the entire population is a clone. If you'd prefer a mamalian example, the limited gneteic variation of the Cheetah is well known - but people often forget that until recently it was very successful with a huge range across Africa and Asia - one of the most widespead of all mammals. Andrew Taylor
We now know that placental mammals were present in Australia before it was isolated by the breakup of Gondwana ~50 million years ago. Unlike marsupials and monotremes, these placentals did not persist into the present.
The introduction of various placental mammals into Australia in the last 200 years has been a large factor in the extinction of a number of marsupial species. However, these introductions have also a large factor in a similar number of extinctions of Australian placentals - rodent species whose ancestors managed the sea journey from Asia in the last few million years.
Neither data point suggests placental "superiority".
While monotreme diversity is extremely limited, one monotreme, the Short-beaked Echidna, is rather successful - ranging over the entirety of Australia and occupying habitats as diverse as alpine grasslands, desert and tropical rainforests. Few placentals can make such claims.