The Process of Domestication

Domestication was not an innovation restricted to farming societies. The first of all domestic animals-the dog-was domesticated by hunter-gatherers during the Paleolithic Age. which ended roughly 12,000 years ago. Analysis of DNA lineages suggests an initial domestication at least 14.000 and perhaps as much as 135.000 years ago. Hunter-gatherers often develop close relationships with key plants as well as with animal species, which lead to practices verging on domestication. Certain Australian Aborigines, for example, followed a practice of replanting parts of the yams that they dug up. In northern Australia the practice was to eave the main plant and its root, and to collect and consume only the side tubers; in western Australia, however, people dug up the tubers, broke them into pieces, and returned some parts to the ground. Even more elaborate practices occurred elsewhere: the Owens Valley Paiute tribe of eastern California diverted streams to irrigate natural “fields” of water-meadow root crops.

Two conclusions may be drawn from this. First, that hunter-gatherers were not simply passive bystanders in the history of plant and animal exploitation, but modified those species on which they relied, both intentionally and unintentionally. And second, that close relationships between humans and their food sources did not begin abruptly with the development of agriculture less than 10,000 years ago in the early postglacial period, but have a much longer history stretching back tens of thousands of years into the Paleolithic.

Domestication involves the removal of species from the wild and their propagation by humans within a sheltered or manipulated setting. As a result, domesticates are subjected to different selective pressures from their wild relatives and so undergo morphological and genetic change from their wild ancestors through processes of natural selection. Domesticated species are also subject to selection by humans, who may prefer smaller and more docile individuals in a herd, for example, or may breed new forms that have specially valued characteristics, such as woolly sheep.

Other consequences of human contact may be unintentional. In a now-classic experiment, Jack Harlan harvested wild stands of cereals by hand in southeast Turkey and showed that it was possible for a small family group to gather in only three weeks enough to sustain them for a year. It is important to consider the effect of such collection on plant communities, in particular on the way in which plants reseed themselves. Those with brittle seed heads will drop their seeds to the ground as soon as they are touched, so those with tougher seed heads will be preferentially gathered by human collectors. Should human collectors use the plants they gathered as the basis of next year’s crop, they will be sowing the tougher seed head variety, thus altering the characteristics of the species overall. It may have been through this sort of process of unintentional selection that domesticated forms of wheat and barley first developed in Southwest Asia.

There were other common changes in domesticated species. A reduction in body size among animals occurred, either through intentional selection or as the unintentional result of breeding conditions. It should be noted, however, that size reduction is a widespread feature of postglacial mammals and has affected humans as well as animals. There is evidence also for an increase in size among cereals and tubers, through selective propagation. Studies in the dry valleys of Mexico, for example, have demonstrated the dramatic size increase of maize cobs that can occur through intentional selection.In addition, incidental changes, such as twisted horns in goats, or the loss of natural coloring in cows or horses, may be due to the relaxation of natural selective pressures in the protected humanly controlled environment; black and white Friesian cows, for example, would be conspicuous to predators and thus have reduced adaptive fitness in the wild.

The eventual result of these changes was the emergence of distinct domesticated species, many (though not all) of which could no longer survive in the wild without human intervention. Furthermore, the success of the new food-producing economy, based on effective combinations of domestic plants and animals (such as the triad of maize, beans, and squash in the Americas) led to its relatively rapid expansion at the expense of hunting and gathering. As a result, species were carried by human action to areas far beyond the geographical range of their wild ancestors.

 

 

1

Domestication was not an innovation restricted to farming societies. The first of all domestic animals-the dog-was domesticated by hunter-gatherers during the Paleolithic Age. which ended roughly 12,000 years ago. Analysis of DNA lineages suggests an initial domestication at least 14.000 and perhaps as much as 135.000 years ago. Hunter-gatherers often develop close relationships with key plants as well as with animal species, which lead to practices verging on domestication. Certain Australian Aborigines, for example, followed a practice of replanting parts of the yams that they dug up. In northern Australia the practice was to eave the main plant and its root, and to collect and consume only the side tubers; in western Australia, however, people dug up the tubers, broke them into pieces, and returned some parts to the ground. Even more elaborate practices occurred elsewhere: the Owens Valley Paiute tribe of eastern California diverted streams to irrigate natural “fields” of water-meadow root crops.

The phrase “verging on” in the passage is closest in meaning to

Adependent

Bclose to

Cresulting from

Dequal to

 

2

Domestication was not an innovation restricted to farming societies. The first of all domestic animals-the dog-was domesticated by hunter-gatherers during the Paleolithic Age. which ended roughly 12,000 years ago. Analysis of DNA lineages suggests an initial domestication at least 14.000 and perhaps as much as 135.000 years ago. Hunter-gatherers often develop close relationships with key plants as well as with animal species, which lead to practices verging on domestication. Certain Australian Aborigines, for example, followed a practice of replanting parts of the yams that they dug up. In northern Australia the practice was to eave the main plant and its root, and to collect and consume only the side tubers; in western Australia, however, people dug up the tubers, broke them into pieces, and returned some parts to the ground. Even more elaborate practices occurred elsewhere: the Owens Valley Paiute tribe of eastern California diverted streams to irrigate natural “fields” of water-meadow root crops.

According to paragraph 1, hunter-gatherers are known to have engaged in each of the following practices EXCEPT

Areplanting parts of certain plants that they had dug up in order to consume

Bcollecting only some parts of certain food plants and leaving other parts in place

Cchanging the course of streams to provide water for certain kinds of plants

Dplanting food plants in places where water was readily available

 

3

Two conclusions may be drawn from this. First, that hunter-gatherers were not simply passive bystanders in the history of plant and animal exploitation, but modified those species on which they relied, both intentionally and unintentionally. And second, that close relationships between humans and their food sources did not begin abruptly with the development of agriculture less than 10,000 years ago in the early postglacial period, but have a much longer history stretching back tens of thousands of years into the Paleolithic.

Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.

AAnd second, close relationships between humans and their food sources began in the early postglacial period that stretched back tens of thousands of years into the Paleolithic.

BAnd second, close relationships between humans and their food sources began to develop not with the beginning of agriculture, but tens of thousands of years earlier.

CAnd second, agriculture began less than 10,000 years ago in the early postglacial period following the Paleolithic, which stretched back many thousands of years

DAnd second, the development of agriculture led to close relationships between humans and their food sources tens of thousands of years ago.

 

4

Domestication involves the removal of species from the wild and their propagation by humans within a sheltered or manipulated setting. As a result, domesticates are subjected to different selective pressures from their wild relatives and so undergo morphological and genetic change from their wild ancestors through processes of natural selection. Domesticated species are also subject to selection by humans, who may prefer smaller and more docile individuals in a herd, for example, or may breed new forms that have specially valued characteristics, such as woolly sheep.

According to paragraph 3, woolly sheep were a new form that resulted from

Anatural pressures of living in a herd

Bselective pressures favoring smaller size

Cprocesses of natural selection

Dintentional selection by humans

 

5

Other consequences of human contact may be unintentional. In a now-classic experiment, Jack Harlan harvested wild stands of cereals by hand in southeast Turkey and showed that it was possible for a small family group to gather in only three weeks enough to sustain them for a year. It is important to consider the effect of such collection on plant communities, in particular on the way in which plants reseed themselves. Those with brittle seed heads will drop their seeds to the ground as soon as they are touched, so those with tougher seed heads will be preferentially gathered by human collectors. Should human collectors use the plants they gathered as the basis of next year’s crop, they will be sowing the tougher seed head variety, thus altering the characteristics of the species overall. It may have been through this sort of process of unintentional selection that domesticated forms of wheat and barley first developed in Southwest Asia.

Paragraph 4 suggests that humans who harvested wild stands of cereals by hand preferred tougher seed heads because those are

Amore nutritious

Beasier to collect

Cmore common

Dlarger

 

6

There were other common changes in domesticated species. A reduction in body size among animals occurred, either through intentional selection or as the unintentional result of breeding conditions. It should be noted, however, that size reduction is a widespread feature of postglacial mammals and has affected humans as well as animals. There is evidence also for an increase in size among cereals and tubers, through selective propagation. Studies in the dry valleys of Mexico, for example, have demonstrated the dramatic size increase of maize cobs that can occur through intentional selection.In addition, incidental changes, such as twisted horns in goats, or the loss of natural coloring in cows or horses, may be due to the relaxation of natural selective pressures in the protected humanly controlled environment; black and white Friesian cows, for example, would be conspicuous to predators and thus have reduced adaptive fitness in the wild.

Why does the author mention that “size reduction is a widespread feature of postglacial mammals”?

ATo point out that size reduction was the most common change in domesticated species

BTo indicate that the assumed connection between smaller animals and domestication may be open to question

CTo suggest that size reduction was more likely the result of intentional selection than an unintended result of breeding conditions

DTo support the idea that domestication affected mammals of all kinds more differently than it affected plants such as cereals and tubers

 

7

There were other common changes in domesticated species. A reduction in body size among animals occurred, either through intentional selection or as the unintentional result of breeding conditions. It should be noted, however, that size reduction is a widespread feature of postglacial mammals and has affected humans as well as animals. There is evidence also for an increase in size among cereals and tubers, through selective propagation. Studies in the dry valleys of Mexico, for example, have demonstrated the dramatic size increase of maize cobs that can occur through intentional selection.In addition, incidental changes, such as twisted horns in goats, or the loss of natural coloring in cows or horses, may be due to the relaxation of natural selective pressures in the protected humanly controlled environment; black and white Friesian cows, for example, would be conspicuous to predators and thus have reduced adaptive fitness in the wild.

In paragraph 5, the loss of natural coloring in cows or horses is presented as an example of

Aa change that may have been an accidental effect of domestication

Ba change that is most likely to have resulted from intentional human selection

Ca change that resulted from natural selective pressures

Da change that creased adaptive fitness in protected environments

 

8

The eventual result of these changes was the emergence of distinct domesticated species, many (though not all) of which could no longer survive in the wild without human intervention. Furthermore, the success of the new food-producing economy, based on effective combinations of domestic plants and animals (such as the triad of maize, beans, and squash in the Americas) led to its relatively rapid expansion at the expense of hunting and gathering. As a result, species were carried by human action to areas far beyond the geographical range of their wild ancestors.

 

According to paragraph 6. each of the following came about as a result of the development of domestication EXCEPT

Athe appearance of species that could not survive in the wild

Ba decline in hunting and gathering

Cthe relocation of hunter-gatherer economies to different areas

Dspecies being carried to areas outside their original geographical range

 

9

Look at the four squaresthat indicate where the following sentence could be added to the passage

Studies in the dry valleys of Mexico, for example, have demonstrated the dramatic size increase of maize cobs that can occur through intentional selection.

Where would the sentence best fit？Click on a square  sentence to the passage.

10

Long before humans stopped being hunters and gatherers, they had begun to influence the history of plant and animal species.

AHunter-gatherers developed close relationships in the wild with the plant and animal species on which they relied, and, in doing so hanged them both intentionally and unintentionally.

BExperimental evidence suggests that domestication was slower to occur in locations where small family groups could quickly gather enough cereal to live on for a year

CDomesticated species are subject to intentional selection by humans for valued characteristics, but many changes in domesticated species may be the unintentional results of breeding conditions

DTrue domestication involves removing species from the wild and propagating them within a humanly controlled environment in which they are subject to different pressures than their wild relatives.

EWhile some humans gave up hunting and gathering to become part of the new food-producing economy. there were many others who preferred wild as opposed to domesticated food sources.

FHumans selected for characteristics such as the twisted horns in goats in order to reduce the adaptive fitness of domesticated animal in the wild.

 

答案请付费后查阅：