Darwins 5 facts and 3 inferences

Fact 1

Fact 1

All species have such great potential fertility that their population size would increase exponentially if all individuals that were born reproduced successfully

Fact 2

Except for minor annual fluctuations and occasional major fluctuations, populations normally display stability in size

Fact 3

Natural resources are limited. In a stable environment they remain relatively constant

Fact 4

No two individuals are exactly the same; rather, every population displays enormous variability

Fact 5

Much of this variation is heritable

Inference 1

because more individuals are produced than can be supported by the available resources and population size remains stable, it means that there must be a fierce struggle for existence among the individuals of a population, resulting in the survival of only a part, often a very small part, of the progeny of each generation

Inference 2

Survival in the struggle for existence is not random but depends in part on the inherited traits of the surviving individuals. This unequal survival constitutes the process of natural selection

inference 3

Over the generations this process of natural selection will lead to a continuing gradual change of populations, that is, to evolution and to the production of new species