This definitions covers Key Definitions within Evolution for GCSE Biology. Theory of evolution, natural selection, and evidence for evolution It is section 6 of 12 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Topic position
Section 6 of 12
Practice
26 questions
Recall
25 flashcards
Key Definitions
Evolution: A change in the inherited characteristics of a population over many generations, driven by natural selection acting on genetic variation.
Natural selection: The process by which individuals with advantageous characteristics are more likely to survive, reproduce, and pass on the alleles for those characteristics to offspring.
Survival of the fittest: A phrase describing natural selection — "fittest" means best adapted to the environment, not necessarily strongest or largest.
Adaptation: A feature of an organism that increases its chances of survival and reproduction in its particular environment.
Speciation: The formation of a new species when two populations of the same species become reproductively isolated, diverge genetically, and can no longer interbreed to produce fertile offspring.
Extinction: The permanent loss of a species when all its members die and no individuals remain to reproduce.
Darwin: Charles Darwin (1809–1882) — the scientist who proposed the theory of evolution by natural selection after his voyage on HMS Beagle. Published On the Origin of Species in 1859.
Lamarck: Jean-Baptiste Lamarck (1744–1829) — proposed an earlier, incorrect theory that organisms pass on characteristics acquired during their lifetime (e.g., a giraffe stretches its neck and its offspring are born with longer necks). Now disproved.