Evolution
Evolution refers to the change in organisms over time , also known as “ descent with modification “.
Big names in history of evolution :
1. Aristotle – came up with naturalistic model of evolution as levels of increasing linear complexity .
2. Charles Lyell (1830) – A geologist that published Principles of Geology , promoted the idea of
uniformitarianism (processes that shape Earth now , shaped it in the past )
Proposed that changes to Earth occur over long time , no short rapid changes.
3. Lamarck – recognized that species change over time in response to the environment. Also recognized
that traits are passed onto generations . Suggested the plasticity of species , that they can be modified .
Developed law of use and disuse and law of inheritance of acquired traits suggesting that species
change by will/ innate drive.
4. Charles Darwin (1809) – was an avid reader , was forced to study medicine which he hated . He
accompanied Robert Fitzroy ( captain of HMS Beagle ) in 1831-36 as a naturalist . Stopped at
Galapagos Islands and observed finches , they had different beak size , which led to different seed
preferences. Darwin then proposed Natural Selection as the mechanism of evolution.
Factors that influenced Darwin’s Natural Selection.
- Diversity of life
- Adaptations
- Fossils & extinct forms
- Galapagos islands.
- Geology
Darwin was hesitant with publishing his work , till Alfred Wallace came to same conclusions as
Darwin.
Central ideas of Darwin’s Natural Selection.
- More offspring are born than survive to reproduce .
- Variations exists in all species .
- Survival of the fittest.
- Species change of time ( descent with modification )1
Biological fitness : refers to the ability to reproduce .
Forms of evolution
