scopeofzoology

therefore, the whole interbreeding population, and it is in his dealings with populations that
the biologist is distinguished from other scientists.
To summarise, the way to study wallflowers, rats or men is first and foremost, to examine
them whole, to see how their actions serve to meet the requirements of the environment and
so allow the preservation of the life of the individual and race. Then, with this knowledge of
how the animal 'uses' its parts, we are able to make more detailed studies down to the
molecular level and show how, together, the activities form a single scheme of action.
Action is the characteristic feature of living, compared with lifeless, matter. To most people,
animals are generally more lively than plants. Even when asleep, an animal is breathing, its
heart is beating and brain pulsing. The waking life, of course, shows this restless action even
more clearly. It is at this level of 'animals-alive' that we see the side of biology that is most
interesting to the bulk of humanity. However, to make sense of animals alone or in groups is
very difficult and it is no accident that it is more often found that the easier path is taken and
we spend our time examining the structure and chemistry of the dead.
Animals versus plants
Following the line of defining zoology, there remains the problem as to the fundamental
difference between plants and animals. Why do we call this organism a plant and this an
animal? Most people would not hesitate, but would say that the animal moved, whereas the
plant did not; that the animal was conscious, while the plant was not; that the animal
devoured its food while the plant absorbed its nutriment from its surroundings. None of these
criteria, however, are absolute.
Many animals, like corals or sea squirts are as rooted to the spot as most plants, while some
undoubted plants move about. With regard to consciousness, no-one could assert with
confidence that a sponge, an undoubted animal, possessed a higher level of consciousness
than a mushroom or a wallflower. On the point of nutrition, many animal parasites absorb
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