地球已人满为患!40亿的人充塞着每一个适于居住的、富饶的地区,甚至那些不宜生活的不毛之地,也到处都有人类的足迹。在人口日益膨胀的压力下,旷野正在消失;在与人类的生存竞争中,许多植物和动物正在灭绝;气候正在发生变化,土壤日趋贫瘠。但对人类来说,与自然环境的恶化相比,人满为患也许是一个更为严重的危险。约400万年以前,人类起源于东非;那时仅仅是一群为数不多的原始人。约200万年前,最早的原始人在人体结构上 The Earth is overcrowded! 4 billion people stuff every living, fertile area, even those who are not suitable for living in the country, but also have human footprints everywhere. The wilderness is disappearing under growing population pressure; many plants and animals are extinct in competition with human existence; the climate is changing and the soil is becoming increasingly barren. But for humans, overcrowding may be a more serious danger than the deterioration of the natural environment. About four million years ago, humans originated in East Africa; at that time, they were just a few primitive people. About two million years ago, the earliest primitives were on the human body