Natural selection involves systematic differences in expected reproductive success associated with variation in phenotype. For a continuing evolutionary response, the relevant variation must be inherited: offspring must tend to preserve the differences being favored. Actual offspring counts also fluctuate by chance, producing genetic drift. Survival matters insofar as it affects contribution to future generations. Genotype fitness is therefore contextual, depending on environment and the life cycle being counted, rather than simply measuring strength or longevity. See Clark, Douglas and Choi, Biology 2e: population evolution.
In chapter IV of his 1859 book, Darwin explained natural selection through preservation of favorable variations and greater chances of survival and reproduction. See Darwin, On the Origin of Species, first edition, chapter IV. The beautiful consequence is cumulative change without foresight: inherited differences are filtered repeatedly by present conditions. Natural selection neither generates a needed mutation on demand nor guarantees progress toward a predetermined goal.
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Natural selection is a fundamental mechanism of evolution proposed by Charles Darwin. It is the process through which certain traits become more or less common in a population due to differential survival and reproduction of individuals based on their characteristics. Here are the key components of natural selection: 1. **Variation**: Within a population, there is variation in traits (such as size, color, speed, etc.) among individuals. This variation can be due to genetic differences and environmental influences.
