Learn: Evolution

Anaximander of Miletus

First land-dwelling ancestors of humans were born in water, and the

first human must have been the child of a different type of animal (fish)

Xenophanes

recognized fossils (fish and shellfish) as evidence of past lif

Aristotle

Created the "Scala Naturae", hierarchy of life from simple to complex

Lucretius

(De rerum natura) - development of the

cosmos, earth, life, & humans through mechanistic mechanisms.

Roman Stoic Philosophers

nature as an agency

concerned with "life best fitted to survival" by purposeful design.

Origen of Alexandria,

Gregory of Nyssa, Augustine of Hippo

Genesis as allegory and "theistic evolution"- life transformed over time

directed by the creator

Great chain of being

links were designed

& forged at the same time at center of creation and were immutable.

Georges Louis Leclerc de Buffon

- life could be generated spontaneously

- life was not immutable but may degenerate from a perfect form

- environment influences modifications

- earth was older, 75,000 years (views published in a 44-volume

natural history book series, Histoire Naturelle)

Erasmus Darwin

published multiple works

- competition play role in species formation (not creation)

- animals change in response to changes in the environment

- offspring inherit these changes

James Hutton (late 1700's) & Charles Lyell

Theory of Uniformitarianism

(changes in the earth occurred slowly, gradually and at uniform rates)

- Lyell published ideas in the book "Principles of Geology"

- age of earth determined by sedimentation rates

- earth was very old (millions of years)

William Smith (Paleontologist - mid 1800's)

Principle of Faunal Succession (different layers of rock substrata

contained distinct fossil assemblages), Geologic map of England

- linked age of rocks to age of fossils

Georges Cuvier

- established the science of paleontology

- fossils represent species that went extinct (extinction as fact)

theory of Catastrophism

(Earth's geology & life were determined by repeated catastrophic events)

- current diversity due to survivors & immigrants not new species

Jean Baptiste de Lamarck

Inheritance of Acquired Characteristics (traits)

(Environmental pressures and internal needs bring about permanent

changes in body form and function) - behaviors modified traits

Charles Darwin

- 1825 attended University of Edinburgh (medicine), transferred to

Cambridge (clergy) and graduated in 1831

- At 22 years old took a position as "Captain's Companion"

- 5 years voyage 1831-1836 (H.M.S Beagle)

- Survey of geography, oceanography, geology & biology

Development of Evolutionary Thought

- Devised the Theory of Natural Selection (1837), draft essay (1844) did

not publish

3 Major Findings:

1. As environment changes so does species composition

2. Fossils are related to organisms today but are also

structurally different

3. Galapagos islands: island animals were related to mainland

species but locally different in form and function, Ex: Finches

Thomas Malthus

- "Essay on the Principle of Population"

(geometric growth of populations)

- All populations have the capacity to produce

more individuals than the environment can support.

Alfred Russel Wallace

- Independently wrote 2-page letter summarizing same ideas as

Darwin's on natural selection. "Survival of Fittest"

Wallace

- 2 papers presented in 1858 (Darwin & Wallace) at the Proceedings of

the Linnaean Society of London

- Darwin (1859) published book "On the Origin of Species"

Fleeming Jenkins

Swamping Argument (1867) - inaccurate

- unusual variants occasionally arose (sports or monstrosities)

- variant likely to mate with individuals with most common trait

- offspring will be a blend of that trait

- in only a few generations the novel trait will be "swamped" out

Erich von Teschermak, Carl Correns, & Hugo de Vries

Independently rediscovered Mendel's work and confirmed it (35 yrs later)

Hugo de Vries

Theory of mutation "mutare": (early 1900's)

- spontaneous mutation was the source of variation

- inheritance of specific traits in organisms via particles (pangenes)

R. A. Fisher

- extends Mendel's work (discrete characteristics) to continuous traits

- 1918 published paper on Quantitative Genetics

- 1930 published paper on Genetical Theory of Natural Selection (unified

the theory of Natural Selection and Mendel's laws of inheritance

Stephen Gould and Niles Eldredge:

- Theory of Punctuated Equilibrium

- Long periods of stability (stasis) punctuated by bursts of evolutionary

change and diversification