Thylacine (Tasmanian tiger) Australia
Roughly the size of a large dog, the thylacine or Tasmanian tiger (Thylacinus
cynocephalus) was a striped carnivorous marsupial that lived on Australia,
Tasmania, and New Guinea. Tasmania was its last stronghold, but the animal
was pronounced extinct in the 1930s. Loss of habitat and introduced dogs
likely played a role, although most biologists point to hunting as a primary
cause.
Moa (a flightless bird) New Zealand
The moa were a group of nine species (in six genera) of large flightless birds
that lived in New Zealand. The largest, Dinornis robustus and Dinornis
novaezelandiae, dwarfed the modern ostrich, reaching a height of 3.6 meters
and weight of 230 kilograms.
Moa disappeared by the year 1400, after being hunted by the Maori, and after
their habitat was disturbed for farmland.
Woolly mammoth
A museum worker inspects a replica of a woolly mammoth (Mammuthus
primigenius), a species that went extinct 3,000 to 10,000 years ago. In March
2012, scientists in Russia and South Korea announced a partnership to try to
clone the mammoth and generate a living specimen.
Gastric brooding frog
In this novel form of parental care, the female swallowed her fertilized eggs.
Her stomach then stopped producing acid, becoming a makeshift womb. Later,
she regurgitated fully formed froglets.
Two species of gastric-brooding frogs made their homes in creeks in a
relatively small area of tropical forest in Queensland, Australia, the southern
gastric-brooding frog (Rheobatrachus silus) and the northern gastric-brooding
frog (Rheobatrachus vitellinus). The species were discovered in 1973 and 1984,
respectively, but by the mid-1980s they had both disappeared.
Biologists aren't sure why the frogs went extinct, but they suspect habitat
degradation, pollution, and possibly disease, including chytrid fungus.
The information and photos were obtained from the National Geographic website where
you can find many other examples of extinct or endangered species.
What do the thylacine, woolly mammoth and gastric-brooding frog all have in common?
For one, they’re all extinct – however, there are some scientists who think that the
extinction of these animals (and others) might not have to be permanent.
Extinctions have happened throughout history, but the rate of extinction varies. For
example, around 66 million years ago huge changes in global climate wiped out whole
groups of species, including dinosaurs. Humans have also caused the extinction of many
species through hunting, habitat destruction and introducing other species into new
ecosystems.
How might it be possible to bring back an extinct species? Firstly, a good quality sample of
the species’ genetic code is required. This can be a problem as many specimens held in
museums have DNA that has degraded over time. However, advances in technology mean
that it is now possible to extract enough genetic information from a range of samples.
Once the species’ genome can be replicated, it needs to be able to grow into an organism.
Current techniques involve implanting the DNA of the extinct species into an egg of a
related species. The idea is that the fertilised egg is then implanted into the related species
where the embryo grows, until the extinct species is reborn. At the moment, the technique
is far from perfect and most attempts have failed.
Even if it does become possible to bring back extinct species, there is the question of
whether or not we should. Those who support ‘de-extinction’ say that it allows us to correct
past mistakes and helps with species conservation. Plus the idea of being able to see living
dodos, moas and thylacines is appealing to many.
There are many who oppose the idea. Attempting to bring back extinct species takes a lot of
time and money – effort that some conservationists say would be better spent addressing
things like habitat destruction which cause extinction in the first place.
Another problem for species that have been extinct for hundreds or thousands of years is
that the ecosystems in which they once flourished may have changed or disappeared.
Individual species may be able to be brought back, but recreating lost ecosystems may be
too hard.
This debate shows that de-extinction is not just scientifically complicated, but ethically
complicated too.
How would you feel if you could see living specimens
of these and other previously extinct species??????
Bringing back extinct species is becoming potentially
possible!!!
The technology of using DNA (cell information) extracted from museum or
university specimens of extinct animals to implant into the eggs of living
animals, which then give birth to babies of the extinct animals, is currently
being developed.
If you saw the movie – Jurassic Park – this is the scientific process behind the
development of the living dinosaurs in the park!
Would it give conservation movements something new
to generate excitement, or does it generate apathy, so
people ask 'why do we need to care about saving
them in the wild if we can bring them back?’
Bush Blitz and Earthwatch are trying to learn about and
improve the conservation status of many plants,
animals and natural areas in Australia. The aim is to
protect the species we have now rather than lose more.
What do you think?
Think about the positives and negatives of ‘cloning’ extinct species. Discuss in
your groups some of the good things or the bad things that may arise if we can
perfect this process and start to bring back to life some of the extinct animals.
Ideas to consider Food requirements – especially for species from long ago
Environment needs – has the earth changed significantly – can the species
adapt to new physical environments?
Climate needs - has the earth changed significantly – can the species adapt to
new climatic environments?
Safety of both people and the animals
Size of populations – do you just keep growing new ones as the die or do you
develop large enough populations to breed and reproduce naturally?
Knowledge of species medical/veterinary needs
Is the artificial introduction into the current world appropriate for an extinct
species – animals may live in groups or pairs or in a solitary situation. We may
not know – they may have been too long extinct.
Competition with modern species – food, space, habitats.
Would they be kept in zoos, as pets, in scientific research institutions or let out
in to the natural environment?
Who would be responsible for them?
As a group make a decision – would you vote
 for the conservation of the natural world and the prevention of further
extinction and destruction
or
 do you think we should not bother, seeing as we may soon be able to recreate any species we can extract suitable DNA from?
Elect 1 or 2 speakers to represent your group and present some of your
arguments in a class debate/discussion.
Persuasive Text –
After participating in the group discussion and the joint discussion in the class
forum, decide what you think is the answer to the question –
Should scientists forget about trying to conserve our current natural
environment and the species we have, and instead put all our resources into
developing techniques to bringing extinct species back to life?
 Present a persuasive text to explain your answer with your most
important reasons presented as back up.
 You may present your text in written, typed, audio or video form.
 You might like to attempt to extend your skills and produce a persuasive
poster or alternative presentation.
 Just remember to apply the persuasive text skills you have been
developing.
What do the thylacine, woolly mammoth and gastric-brooding frog all have in common?
For one, they’re all extinct – however, there are some scientists who think that the
extinction of these animals (and others) might not have to be permanent.
Extinctions have happened throughout history, but the rate of extinction varies. For
example, around 66 million years ago huge changes in global climate wiped out whole
groups of species, including dinosaurs. Humans have also caused the extinction of many
species through hunting, habitat destruction and introducing other species into new
ecosystems.
How might it be possible to bring back an extinct species? Firstly, a good quality sample of
the species’ genetic code is required. This can be a problem as many specimens held in
museums have DNA that has degraded over time. However, advances in technology mean
that it is now possible to extract enough genetic information from a range of samples.
Once the species’ genome can be replicated, it needs to be able to grow into an organism.
Current techniques involve implanting the DNA of the extinct species into an egg of a
related species. The idea is that the fertilised egg is then implanted into the related species
where the embryo grows, until the extinct species is reborn. At the moment, the technique
is far from perfect and most attempts have failed.
Even if it does become possible to bring back extinct species, there is the question of
whether or not we should. Those who support ‘de-extinction’ say that it allows us to correct
past mistakes and helps with species conservation. Plus the idea of being able to see living
dodos, moas and thylacines is appealing to many.
There are many who oppose the idea. Attempting to bring back extinct species takes a lot of
time and money – effort that some conservationists say would be better spent addressing
things like habitat destruction which cause extinction in the first place.
Another problem for species that have been extinct for hundreds or thousands of years is
that the ecosystems in which they once flourished may have changed or disappeared.
Individual species may be able to be brought back, but recreating lost ecosystems may be
too hard.
This debate shows that de-extinction is not just scientifically complicated, but ethically
complicated too.