Русско-англо-русский юридический словарь

Self-preservation is a behavior that ensures the survival of an organism. (Wikipedia)

A farmer (also called an agriculturer) is a person engaged in agriculture, raising living organisms for food or raw materials. The term usually applies to people who do some combination of raising field crops, orchards, vineyards, poultry, or other livestock. A farmer might own the farmed land or might work as a labourer on land owned by others, but in advanced economies, a farmer is usually a farm owner, while employees of the farm are known as farm workers, or farmhands. (Wikipedia)

The concept of the struggle for existence concerns the competition or battle for resources needed to live. It can refer to human society, or to organisms in nature. (Wikipedia)

"One of the most remarkable achievements of science over the last two hundred years has been to show how humans and all other organisms on the earth arose through the process of evolution." (BBC)