Sarah Clements
AP Composition period 4
1.11.10
Jurassic Park
After uncovering the science of cloning scientists speculate that it may be possible to
bring back animals of our past in hope to someday create a real-life Jurassic Park. In
order to bring extinct animals back to life scientists must obtain usable DNA from the
species, this is a difficult task considering many of the animals scientists wish to clone
have been extinct for thousands or even millions of years, such as the wooly mammoth
and dinosaurs. With the technology we have now it does not look probably that we will
be able to clone species this long extinct but as research and technology advances it
might not be long before we are capable of bringing long extinct animals back to life.
Scientists now have narrowed their focus on cloning endangered animals and animals that
have recently become extinct in hope to prevent animal extinction altogether.
In order to understand how it may be possible to bring animals back from the dead it is
essential to know how cloning works. In the case of nuclear transfer cloning, the nucleus
(which contains much of the genetic material of eggs and other cells) is removed from the
animal and inserted into an egg that has had its nucleus removed. If all goes well the egg
then forms an embryo and undergoes the normal process of dividing and maturing until it
can be transferred to its surrogate mother (Cloning Dinosaurs). In the case of cloning
extinct animals, intact DNA would have to found, the animal’s genome sequenced, and
the nucleus of a cell would be transferred into the egg of a surrogate mother (an animal
that is closely related to the extinct species). Without perfectly intact DNA cloning is not
possible and even with usable DNA the process of cloning is extensive, expensive and
inconsistent.
Over the last century scientists have proven that cloning can be done with enough
attempts, the right resources, and a large amount of funding. In 1996 scientists
successfully cloned Dolly the sheep, the first mammal to be cloned from an adult cell. In
order to clone Dolly, scientists used the nucleus of an udder cell from a white sheep and
fused it with the egg cell from a black-faced sheep so that the egg would develop into an
embryo. It was then cultured it for six-seven days where it divided and developed before
it was implanted into its surrogate mother. The scientist’s success did not come without
many attempts; of the 237 eggs injected into Dolly, only 29 created embryos; from this
three lambs were born and only one survived. This low survival rate has been seen in
cow cloning as well: of the 9,000 attempts at cow cloning, seventy cows have been
successfully created and one third have died young. (Cloning Dolly) Although the
success rate of cloning attempts have been low, scientists have proven that it can be done,
hoping that as they continue to experiment their success rate will go up.
Scientists now have moved on from the cloning of live species and are beginning to focus
on the cloning of extinct animals which if successful could save endangered species from
extinction. The cloning of an extinct species was first put to the test in 2000 when
scientists preserved skin samples of a Pyrenean ibex in liquid nitrogen shortly before the
last of it’s species was found dead in Northern Spain. Scientists used the DNA from the
ibex and transplanted it into the eggs of a domestic goat in attempt to clone a female
Pyrenean ibex (a bucardo). Of the 439 embryos created 57 were implanted into the goats,
resulting in just seven pregnancies and of those pregnancies one birth, (a similar success
rate to Dolly the sheep). The one female bucardo that was born died shortly after, living
only seven minutes after birth due to breathing difficulties (Extinct ibex). Similar
respiratory problems have been seen in the cloning of other animals, most of which have
not been able to survive for long after their birth. As seen in the Pyrenean ibex the
cloning process is not without faults, it took many attempts to successfully produce a
fetus and even with a successful birth the clone died just a few minutes after. But
regardless of past difficulties, scientists believe that the cloning process will become
more sufficient as technology and research advances and they will someday reach their
goal of cloning the extinct. They are already taking steps towards the preservation of
endangered species by maintaining feasible DNA of these animals in what they call
“frozen zoos”.
After their success with using liquid nitrogen in the cloning process of the Pyrenean ibex,
scientists are using similar techniques in preserving the DNA of endangered animals.
Scientists have created what they call, “frozen zoos” to preserve the DNA of endangered
or recently extinct species. In these frozen zoos skin samples of different animals are
stored at 340 degrees below zero in canisters of liquid nitrogen where they are able to sit
for 100-1,000 years without damage (Resurrecting The Extinct). The San Diego Zoo
currently stores the tissue of 675 endangered species such as sperm, ovaries, cell-lines
and tissues samples from all other parts of the body (Back from the dead). This particular
frozen zoo has been used to clone endangered species such as the cloning of two bantegs
in 2003. To clone the two bantegs DNA was taken from banteg skin cells and put into
the egg of a domestic cow that had had it’s DNA removed. This experiment proved
similar to others as the success rate was low but even still a successful birth was obtained
(Back from the dead).
When it comes to DNA preservation, frozen zoos are not only confined to the laboratory.
The Siberian wastelands have held animals in permafrost for up to 200,000 years. It is
within these wastelands that scientists hope to unleash their greatest discoveries. Already
scientists have discovered mammoth remains and other long extinct species in the tundra
of the Siberian wastelands. Recently, a 1-month baby mammoth was discovered frozen
in the permafrost of Siberia by a Siberian reindeer herder; scientist’s estimate the baby
mammoth has been frozen for up to 40,000 years. The DNA of this baby mammoth is
the best mammoth DNA that has been uncovered so far, this brings hope to scientists that
it will only be a matter of time before usable mammoth DNA is discovered (Resurrecting
the Extinct). Scientists are racing to uncover ancient animal remains before the climate
changes, permafrost melts, animal carcasses begin to rot, and the animal DNA becomes
no longer usable.
Even with the recent success of cloning newly extinct species scientists have a long way
to go before they reach their dream of bringing back prehistoric life. Last year scientists
sequenced the genome of a wooly mammoth by analyzing hairs recovered from remains
in Siberia. This is the first time that DNA from an extinct animal has been fully recreated.
(Dinosaurs: What the future holds). But as Dr Jeremy Austin, deputy director of the
Australian Centre for Ancient DNA at the University of Adelaide says, "A genome
sequence does not make a living organism; scientists still have a long ways to go before
they can even come close to cloning the mammoth. "Currently we only have a partial
mammoth genome, with a sizeable number of errors in the code. It's a bit like trying to
build a car with only 80 percent of the parts, and knowing that some of them are already
broken.” (Extinct ibex) There is no debating the furry elephant is nowhere near walking
this earth but that does not rule out the possibility. Both sides are represented, many
scientists believe it may be possible in the future whereas there are many that argue they
will not find enough usable DNA to recreate the mammoth. The sequence of mammoth
DNA is estimated to be more than 4.5 million base pairs long; of this 4.5 million
scientists have successfully sequenced 70% and still need to recover the remaining 30%.
Even with the needed 30%, the genome would likely be full of errors due to centuries of
degradation, these errors would have to be sorted out before the DNA had a shot at being
be used. Even with these complications many scientists still believe it is possible, "It's a
simple question of time and money, not of technology anymore," says Schuster. (Cloned
Species)
As for creating a real life Jurassic park the prospects seem nearly impossible. "Recreating
DNA from a mammoth is one thing," Milner says. "The remains are recent - around
27,000 years old - and frozen, so it is not surprising they were able to locate a long,
undamaged sequence of DNA. By comparison, given that dinosaurs lived millions of
years ago, it's extremely unlikely that their DNA will ever be discovered, since DNA is
very fragile and can't survive over millions and millions of years." (Dinosaurs: What the
future holds). In order for cloning to be possible usable DNA is required; this means the
DNA sequence must be intact and complete in order to use it for cloning. In order for the
cloning of dinosaurs to be possible, usable DNA that has survived for millions of years
would have to be found. And if scientists were able to uncover preserved DNA they can
almost be certain that the DNA fragments will be damaged or disintegrated and would
find it extremely difficult to use this DNA in creating accurate genome sequences. As of
now the prospects of a Jurassic Park seem unlikely--it would be nearly impossible for
something as fragile as DNA to survive millions and millions of years. And even if some
preserved dinosaur DNA is uncovered the likelihood of finding enough to sequence the
genome of an entire dinosaur is highly unlikely. In the hit film Jurassic Park,
DNA samples from a mosquito who had bit a dinosaur was used recreate the ancient
beasts, but in reality the DNA carried by the mosquito is only a tiny part of the dinosaurs
DNA and not nearly enough to recreate it.
Even if it is possible to bring back the animals that crowd prehistoric exhibits in today’s
museums is it in our best interest to have dinosaurs roaming this earth when their natural
environment is long extinct? If we defy nature’s plan in our goal to keep all species on
this earth around for all eternity, what kind of affect will this have on our planet? We
already face issues such as overpopulation and global warming that threaten our planets
existence, further tapering with natural evolution can only lead to greater issues. It is still
debatable whether we will ever have the resources to bring dinosaurs back to life, but
even if the resources do become obtainable I do not believe that it will be in human
interest to do so. To bring the once domineering animals of our planet back to a world
that is vastly different from the environment they once ruled would be illogical and
irresponsible. Not to mention the affect it would have on human life. After all, we all
saw the chaos that unleashed in Steven Spielberg’s version of Jurassic Park.