If today you replaced half of the world with its mesozoic
equivalent - and then waited a few thousand years - I reckon
most of the metazoic fauna and flora will have been wiped
out in competition with modern forms - in a similar way to
the way most marsupials don't stand up to competition with
placental mammals. It would be a war of technology - the
humans would obliterate the therapsids and archosaurs much
as they are wiping out most of the modern large predators -
by destroying or occupying their habitat - and by shooting
them. The humans - and their ecosystem - would win because
they have better technology on a range of fronts. It's
perhaps a bit of a stretch to refer to something like
"technological prowess" as a sort of fitness - but that's
what I was talking about - not how many kids an organism
has, is expected to have - or anything like that.
Tim Tyler
___________________________________
Perhaps your mention of marsupials being outcompeted by
humans was recently sparked by the following news story:
Koalas face extinction, activists warn Australian group
cites loss of habitat to development
David Gray / Reuters file
The future for these twin koala bears and their peers
is bleak after an Australian group found that 30
percent of 1,000 habitat sites surveyed no longer had
koalas living there.
SYDNEY - Koalas, Australia's iconic symbol, face extinction
as rapid urbanization along the eastern seaboard destroys
their fragile habitat, the Australian Koala Foundation is
warning. The group has written to the government urging it
to declare the koala a vulnerable species after a survey of
1,000 koala habitats found 30 percent no longer had a koala
in them and 60 percent had suffered widespread destruction.
"I truly believe that in my lifetime the koala will become
extinct unless we do something," said Deborah Tabarat,
executive director of the foundation.
Koalas are protected by law but the eucalyptus trees
they call home and which provide their only source of
food are not.
There are about 100,000 koalas in Australia, down from an
estimated seven to 10 million at the time of white
settlement in 1788. In the 1920s, three million koalas were
shot for their fur.
Tabarat said the major problem facing koalas was that the
majority of Australia's 20 million people and the majority
of the koala population both call Australia's eastern states
home. Eastern koalas extinct in 15 years? She said that with
80 percent of Australia's east coast temperate forests
destroyed and continued rapid urbanization, koalas along the
eastern seaboard could be extinct in 15 years.
"This animal is in serious trouble," said Tabarat. "In 15
years you will not see a koala west of the divide," she
said, referring to the Great Australian Divide, mountains
that divide east coast Australia from its rural outback.
Wild koalas only exist in four of Australia's six states:
Queensland, New South Wales, Victoria and South Australia.
The marsupial has no natural predator, but has been in
decline for decades due to urban sprawl and from car
accidents and dog attacks. More than 4,000 koalas are killed
each year by dogs and cars, the foundation says.
The most robust koala population on the Australian mainland
exists in southeast Queensland and numbers about 10,000, but
it too faces extinction in 15 years, said Tabarat. Southeast
Queensland is experiencing the most rapid population growth
of any part of Australia. Over the past eight years, 16,000
koalas in the area died in accidents with cars or dog
attacks and another 10,000 injured koalas probably died in
the bush, said Tabarat. Fussy eaters
Diminishing habitat has a greater affect on koalas than most
animals. Koalas live in tall eucalyptus trees and low
eucalyptus woodlands, but they are fussy eaters. There are
about 600 species of eucalyptus in Australia, but koalas
only eat about 120, with koalas in specific areas eating
only four to six different types.
An adult koala eats up to one kilogram of leaves each night.
Like a pasture for sheep, a eucalyptus forest or woodland
can only support a certain number of koalas, resulting in
starving koalas in over-populated habitats or destroyed
habitats. A koala population explosion on Australia's remote
Kangaroo Island off the south coast has prompted calls for
20,000 koalas to be shot to stop them destroying their
habitat. The island has some 30,000 koalas struggling to
survive. Koalas are also very social animals, living in
stable societies that tend to remain in a small "home
range," which means they require habitats large enough to
support a healthy population and to allow for expansion by
maturing young koalas.
"People knock down all the scrub and leave a couple of trees
and think koalas will be okay," said Tabarat. "We might be
looking at koalas who are living happily in the bush but you
might actually be looking at an extinct population," she
said. "They haven't got any way of going out of their little
home range, mating with someone then coming home pregnant.
They just sit there, eke their time out, and then the bush
will go silent."
Copyright 2004 Reuters Limited.
You state in part, "in a similar way to the way most
marsupials don't stand up to competition with placental
mammals. It would be a war of technology - the humans would
obliterate the therapsids and archosaurs much as they are
wiping out most of the modern large predators - by
destroying or occupying their habitat - and by shooting
them. The humans
- and their ecosystem - would win because they have better
technology on a range of fronts."
Mr. Tyler, you are correct about humans technologically
outcompeting marsupials on all fronts. Although I
haven't checked the status of other marsupials certainly
the koala is being outcompeted and there are a number of
reasons for this.
I live in one of the most highly "technologically" congested
areas in the world and believe me quality of life
considerations aren't taken into consideration...money is.
It's interesting how you dichotimize between the ecosystem
of marsupials and placental mammals. In the past many other
animals became extinct or close to extinction because of
humans shooting them for their fur, tusks, body parts, etc.
In fact, many other animals and plants face extinction
besides marsupials because of rampant human development and
human's "technological prowess".
I hesitate to call it "technological skill'" because in my
view it is being misapplied. This is through no "fault" of
our own as we are just following the dictates of Darwinian
evolution and we happen to be the Alpha animal which can
destroy anything. But this does potentially have
consequences in the long term..this rampant development of
our "technological prowess".
Many have remarked on the destruction of the rain forests
and the potentially medically and scientifically valuable
specimens in them, not to mention the rain forests provide a
certain percentage of life giving oxygen to our atmosphere.
The more rampant development of our "technological prowess"
without regards to the environment (our environment),
demographics of population, service needs, water, potential
pathologies which result from such conditions, etc, etc. we
will indeed be not only negatively effecting the ecosystem
of marsupials and other plants and animals but ourselves.
In fact, I think we've already arrived there Mr. Tyler.
There are over 6 billion people on earth and overpopulation
is a serious threat. Now perhaps you think such concerns
aren't warranted as eventually massive natural selection
will kick in and wipe out a signifigant percentage of the
human race. But if that happens it seems our "technological
prowess" will have somewhat backfired on us and the
consequences are unpredictable.
Michael Ragland
"It's uncertain whether intelligence has any long term
survival value." Stephen Hawking
