Despite folklore tales in which one species could quickly change into another, local naturalists
studied the species in their local area and came to recognize their discreteness, constancy,
and diversity. Divine order was commonly invoked to explain these findings.
- Levels of organization:
review here
historical timeline
- Local naturalists described the many species living around them.
- Explaining diversity: stability versus change
- Most scientists believed in the divine creation of each species.
- John Ray wrote "The Wisdom of God, Manifest in the Works of the Creation" (1691).
His first book was about the local plants of Cambridge; he distinguished monocots & dicots.
He was first to group bats and whales with mammals.
He pointed out that mammal hearts have 4-chambers while fish hearts have only 2.
- Adaptation was usually attributed to divine benevolence.
(Paley's "Natural Theology" came from this idea, and from John Ray's ideas.)
- To explain diversity, most scientists from Aristotle until about 1830 believed in a
Great Chain of Being (Scala Naturae).
This idea was used to justify:
- Social order (hierarchy) and class structure
- The "divine right of kings"
- "Man's place in nature" (see the quotation above)
- (later on:) racism, sexism, and the search for "missing links"
- Around the time of the French Revolution, social hierarchies (and monarchies) came into question.
New ideas of the Enlightenment included "progress" and environmental determinism.
- Several French scientists (Maupertius, Geoffroy, Lamarck) attributed adaptations to environmental influences.
- William Paley ("Natural Theology") used adaptations as proof of God's existence.
- Charles Darwin explained diversity by branching "descent with modification".
- Darwin also explained adaptation by natural selection.
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