07 Track 7

Unit 3

Disappearing Animals

Chapter 2

Bring Back the Woolly Mammoth?

Page 47

Bring Back the Woolly Mammoth?

Scientists estimate that throughout the course of Earth’s history, more than a billion different species of animals and insects have existed.

Today, there are only about 30-50 million species left, according to the World Animal Foundation.

That means that for every species living on Earth today, 20 more are already extinct.
Scientists study extinct species to get a better understanding of the past. In addition to studying what these species might have been like when they were alive, some scientists are interested in the possibility of seeing some of them walk the Earth again.

There are a number of serious proposals to try to revive extinct species. Some animals on this list include: the woolly mammoth (an elephant-like creature that wandered the plains of Siberia), the moa (a giant flightless bird from New Zealand), the thylacine (also known as the Tasmanian tiger because of the dark stripes down its back), and the bucardo (a mountain goat from Spain).

These animals had very little in common and in most cases lived eras apart. The woolly mammoth, for example, died many thousands of years ago, while the bucardo became extinct only around the year 2000.

But all these species lived at the same time as humans, and humans have been largely responsible for their destruction.

So, it seems somehow fitting that we are now thinking of reviving them. Scientists have proposed reviving an extinct species using two possible methods. In the first method, sex cells (sperm or eggs) are obtained from the extinct animal and are used to fertilize sex cells of a closely related living relative in a laboratory.

For example, sperm from a woolly mammoth could be used to fertilize an egg from a modern-day elephant. The fertilized egg would then be placed in the live female elephant where it would live and grow until it is ready to be born.

The second method involves a type of cloning. In cloning, the DNA of one individual replaces the DNA of another. In the woolly mammoth example, scientists could inject DNA from a mammoth into an egg cell from an elephant.

The cloned egg cell would then be placed into a living elephant and allowed to develop in the same way as a fertilized egg.

But some scientists believe species revival will never happen because both methods are problematic. One of the major challenges is how to obtain enough high-quality DNA from an extinct species to conduct an experiment.

While it is theoretically possible under ideal conditions to preserve genetic material for thousands of years, these conditions rarely occur in real life. For example, researchers have obtained a number of samples of mammoth DNA, but none have been usable.

And the cloning process presents its own problems. Scientists have been able to clone only a few species of animals, and most cloned creatures are frail and don’t live very long.

And there is a final, ethical consideration. Even if we learn how to reproduce an example of an extinct species, that individual could never have a normal life. Its natural environment is most likely gone and it would have no parents to show it how to behave as a member of its species.

So, the animal would remain a curiosity and probably live out its life in a zoo. People question whether it be ethical to revive one of nature’s creatures for such a purpose.

Only time will tell if scientists managed to carry out their ambitious plans. Even if they managed to overcome the scientific problems, they may face opposition from governments or society.

Some even feel it might be more worthwhile for us to focus our efforts on conservation and take care of existing species, so they don’t also go the way of the woolly mammoth.