SO MUCH TO SAVE
Date: 2015-10-07; view: 2046.
The idea of preserving biological diversity gives most people a warm feeling inside. But what, exactly, is diversity? And which kind is most worth preserving? It may be anathema to save-the-lot environmentalists who hate setting such priorities, but academics are starting to cook up answers.
Andrew Solow, a mathematician at the Woods Hole Oceanographic Institution, and his colleagues argue that in the eyes of conservation, all species should not be equal. Even more controversially, they suggest that preserving the rarest is not always the best approach. Their measure of diversity is the amount of evolutionary distance between species. They reckon that if choices must be made, then the number of times that cousins are removed from one another should be one of the criteria.
This makes sense from both a practical and an aesthetic point of view. Close relatives have many genes in common. If those genes might be medically or agriculturally valuable, saving one is nearly as good as saving both. And different forms are more interesting to admire and study than lots of things that look the same.
Dr Solow's group illustrates its thesis with an example. Six species of crane are at some risk of extinction. Breeding in captivity might save them. But suppose there were only enough money to protect three. Which ones should be picked?
The genetic distances between 14 species of cranes, including the six at risk, have already been established using a technique known as DNA hybridisation. The group estimated how likely it was that each of these 14 species would become extinct in the next 50 years. Unendangered species were assigned a 10% chance of meeting the Darwinian reaper-man; the most vulnerable, a 90% chance. Captive breeding was assumed to reduce an otherwise-endangered species' risk to the 10% level of the safest. Dr Solow's computer permed all possible combinations of three from six and came to the conclusion that protecting the Siberian, white-naped and black-necked cranes gave the smallest likely loss of biological diversity over the next five decades. The other three had close relatives in little need of protection. Even if they became extinct, most of their gene would be saved.
Building on the work of this group, Martin Weitzman, of Harvard University, argues that conservation policy needs to take account not only of some firm measure of the genetic relationships of species to each other and their likelihood of survival, but also the costs of preserving them. Where species are equally important in genetic terms, and – an important and improbable precondition – where the protection of one species can be assured at the expense of another, he argues for making safe species safer, rather than endangered species less endangered.
In practice, it is difficult to choose between species. Most of those at risk – especially plants, the group most likely toyield useful medicines – are under threat because their habitats are in trouble, not because they are being shot, or plucked, to extinction. Nor can conservationists choose among the millions of species that theory predicts must exist, but that have not yet been classified by the biologists assigned to that tedious task.
This is not necessarily cause for despair. At the moment, the usual way to save the genes in these creatures is to find the bits of the world with the largest number of species and try to protect them from the bulldozers. What economists require from biologists are more sophisticated ways to estimate the diversity of groups of organisms that happen tolive together, as well as those which are related to each other. With clearer goals established, economic theory can then tell environmentalists where to go.
from The Economist
H Find a word or phrase in the text which, in context, is similar in meaning to:
Paragraph 1
| Paragraph 2
| Paragraph 5
|
I Choose the best answer to the following questions:
1. Dr Solow believes that
A all species should be saved
B all rare species should be saved
C very rare species should be saved
D only some species should be saved
2. Dr Solow's work depended on
A previous biological research
B the cost of preserving cranes
C the premise that not all species are the same
D the premise that all cranes should be protected
3. Endangered species of cranes can be saved by
A keeping them in zoos or wildlife parks
B protecting their habitats
C stopping hunters from killing them
D encouraging them to mate with their cousins
4. Three of the six species of endangered cranes
A were so rare they couldn't be saved
B could be allowed to become extinct
C were less interesting to admire than others
D shouldn't be protected
5. Dr Weitzman's ideas
A disregard Dr Solow's
B contradict Dr Solow's
C take Dr Solow's ideas one step further
D confirm Dr Solow's
6. Dr Weitzman believes that if two species are equally important genetically we should protect
A the rare one
B the less endangered one
C them both
D the one that is more attractive
7. Most species are endangered because
A they are hunted or picked
B biologists haven't classified them
C we don't care enough about them
D the places they live in are being destroyed
8. According to the writer what has to be done first is for
A biologists to instruct economists
B developers to stop destroying habitats
C economists to instruct biologists
D biologists to classify undiscovered species
Hunting rabbits
J Listen to Robert describing what happens when he goes hunting. When you listen for the first time, tick the things that Robert takes with him when he hunts rabbits.
ڤ ferrets
ڤ a purse
ڤ nets
ڤ a spade
ڤ an axe
ڤ a knife
ڤ a flask of coffee
ڤ a gun
ڤ waterproof clothing
ڤ wellington boots
ڤ a dog
K Now listen to the tape again. Below is a list of the things the hunters do when they hunt rabbits. Can you put them in the right order?
| a. They have a cup of tea. b. They place nets over the holes in one set. c. They place nets over the holes in another set. d. They kill the rabbits. | e. They put the ferrets down. f. They collect up the nets. g. They move on to the second set. h. They hang the rabbits on a tree. |
L Now listen a third time and answer these questions.
1. Why is it better to hunt rabbits on a frosty morning?
2. Why must rabbit-hunters be extremely quiet?
3. If the ferret kills a rabbit underground, what do the hunters do?
4. How many rabbits does Robert catch on average?
5. What three things does Robert do with the dead rabbits?
6. Describe what happens in the pub.
M Discuss the following topic with the group: “HUNTING ANIMALS IS A DISGRACEFUL LEISURE ACTIVITY.”
Language awareness: animal images
A The list on the right contains expressions connected with animals. Match each one with an item from the list on the left, to describe a person who:
| 1. is more dangerous than he appears 2. wears clothes which are too young for her 3. is very clumsy 4. has a wrong sense of priorities 5. is in an unfamiliar situation and feels 6. uncomfortable 7. gets two results from one action 8. leaves things as they are and doesn't cause trouble 9. reveals a secret 10. destroys the source of his wealth 11. is a bit obsessed with something 12. gets the biggest part 13. is less frightening than he seems 14. buys something without having seen it 15. is suspicious about something 16. is crazy | a. to smell a rat b. to get the lion's share c. as mad as a March hare d. to let sleeping dogs lie e. mutton dressed as lamb f. his bark is worse than his bite g. to buy a pig in a poke h. to have a bee in his bonnet i. a wolf in sheep's clothing j. to kill the goose that lays the golden eggs k. to kill two birds with one stone l. to let the cat out of the bag m. a fish out of water n. a bull in a china shop o. to put the cart before the horse |
B Match the animal expressions in the list on the left with their definitions in the list on the right.
| 1. It's a dog's life. 2. This is a fine kettle offish. 3. You're flogging a dead horse. 4. These loan repayments are like an albatross round our necks. 5. The chickens will come home to roost. 6. One day you will cry wolf once too often. 7. That's one of our sacred cows, I'm afraid. 8. What is sauce for the goose is sauce for the gander. 9. This test will sort out the sheep from the goats. 10. This candidate is something of a dark horse. 11. We used to think she was an ugly duckling. 12. It's a wild-goose chase, I'm afraid. | a. raise a false alarm b. a poor, wretched existence c. an unattractive child that later becomes beautiful d. bad words and actions will return to trouble us e. a burden we can't get rid of f. something that cannot be criticised without causing great offence g. what is good enough for one person is good enough for another h. a hopeless pursuit of something that doesn't exist or cannot be caught i. separate the good from the bad j. a futile activity k. a chaotic situation l. someone whose abilities are unknown |
C These newspaper headlines all use expressions taken from activities involving animals (e.g. sport, hunting, farming). Can you identify the animal reference and explain the meaning?
1. New president takes the reins
2. No lame ducks in British industry says Chancellor
3. British gas project falls at the first fence
4. New manager in the saddle
5. Rebel MPs return to the fold
6. Existing product range a bit long in the tooth says new manager
7. Surrey puma a red herring say police
8. Police barking up the wrong tree
9. Manager feathered own nest
10. Inflation -we must seize the bull by the horns says Chancellor
11. PM says "I've got the bit between my teeth"
13. Leader riding roughshod over views of party members
14. Neck and neck finish in London marathon
15. Time to chew the cud says defeated candidate
16. Soldiers were sitting ducks
Theme two: The Circus is Coming – Heaven or Hell?
A What do animals do in circuses?
How entertaining would a circus be without animals?
Now read the text quickly and decide what the author's view of the treatment of circus animals is.
| <== previous lecture | | | next lecture ==> |
| THE THIRD CHIMPANZEE | | | TEN DAYS WITH THE CIRCUS |