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scopeofzoology

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therefore, the whole interbreeding population, and it is in his dealings with populations that<br />

the biologist is distinguished from other scientists.<br />

To summarise, the way to study wallflowers, rats or men is first and foremost, to examine<br />

them whole, to see how their actions serve to meet the requirements of the environment and<br />

so allow the preservation of the life of the individual and race. Then, with this knowledge of<br />

how the animal 'uses' its parts, we are able to make more detailed studies down to the<br />

molecular level and show how, together, the activities form a single scheme of action.<br />

Action is the characteristic feature of living, compared with lifeless, matter. To most people,<br />

animals are generally more lively than plants. Even when asleep, an animal is breathing, its<br />

heart is beating and brain pulsing. The waking life, of course, shows this restless action even<br />

more clearly. It is at this level of 'animals-alive' that we see the side of biology that is most<br />

interesting to the bulk of humanity. However, to make sense of animals alone or in groups is<br />

very difficult and it is no accident that it is more often found that the easier path is taken and<br />

we spend our time examining the structure and chemistry of the dead.<br />

Animals versus plants<br />

Following the line of defining zoology, there remains the problem as to the fundamental<br />

difference between plants and animals. Why do we call this organism a plant and this an<br />

animal? Most people would not hesitate, but would say that the animal moved, whereas the<br />

plant did not; that the animal was conscious, while the plant was not; that the animal<br />

devoured its food while the plant absorbed its nutriment from its surroundings. None of these<br />

criteria, however, are absolute.<br />

Many animals, like corals or sea squirts are as rooted to the spot as most plants, while some<br />

undoubted plants move about. With regard to consciousness, no-one could assert with<br />

confidence that a sponge, an undoubted animal, possessed a higher level of consciousness<br />

than a mushroom or a wallflower. On the point of nutrition, many animal parasites absorb<br />

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