世界人口的压力在远古时代,比方说在五十万年前,人类虽然已经能够制造工具,依靠劳动,来维持生活。但那是旧石器时代,人们的劳动工具不多也不精,人类只是依靠经验过日子,生产力水平很低。当时食物的主要来源是依靠采集植物果实、根茎和狩猎某些动物。那时候,人的平均寿命不长,人口也不多。大约在距今七、八千年前,人类进入新石器时代,开始经营农业。从此以后,人们才定居生活,人口渐渐增多起来。据估计,人口在近三百年内的增长情况大抵如表1。 The Pressure of the World’s Population In ancient times, say, 500,000 years ago, humankind had been able to make tools and rely on labor to sustain life. But that was the Paleolithic, people had less or no working tools, human beings lived on their experience, and their productivity was low. At that time, the main source of food was the collection of plant fruits, rhizomes and hunting of certain animals. At that time, the average life expectancy of people was not long and the population was small. About seven or eight thousand years ago, mankind entered the Neolithic period and started farming. Since then, people only settled their lives and the population increased gradually. It is estimated that the growth of the population in the recent three hundred years is roughly shown in Table 1.