Theories of Evolution
• Origin Myths/Cosmologies– Greek – Prometheus– Genesis
Left: Prometheus and AthenaTop: God and Adam
Western examples
Bishop James Ussher
(as painted between1640-1656) Bishop John
Lightfoot
(b. 1601- d. 1675)
Creation as Calculated from The Bible
Ancient Greek philosopher Anaxiamander (611-547 B.C.) and the Roman philosopher Lucretius (99-55 B.C.) conceived of the idea that all living things were related and that they had changed over time.
Lucretius
Comte de Buffon
(Georges Louis Leclerc)
1707-1788
Early Ideas about Evolution
Baron Cuvier
1769-1832 Jean-Baptiste Lamarck
1744-1829
Erasmus Darwin
1731-1802
Other Theories
• Creationism accounts for biological diversity by referring to the
divine act of Creation as described in Genesis.
• Catastrophism is a modified version of Creationism, which
accounts for the fossil record by positing divinely authored
worldwide disasters that wiped out the creatures represented in
the fossil record, who were then supplanted by newer, created
species.
• Intelligent Design states that modern physics and cosmology
have uncovered evidence for intelligence in the structure of the
universe and this intelligence seems to act with us in mind and
that the universe as a whole shows evidence of design.
Jean Baptiste Lamarck, 1744-1829
• French geologist and naturalist
• published Philosophie Zoologique in 1809
• speculated about mechanisms of biological evolution, offered no evidence
• Lyell discussed Lamarck’s ideas in his Principles of Geology
Ideas of Lamarck that were rejected by Darwin• evolution is a process in which living things gradually
become more perfect (more human-like)• because species that evolve and improve leave a gap, new
species must be continually created by spontaneous creation
• the inheritance of acquired characteristics is the mechanism of evolution
(but inheritance of acquired characteristics was not entirely rejected by Darwin)
Charles Darwin: failed medical student, failed divinity student, ardent beetle collector, naturalist on HMS Beagle
Darwin’s voyage on HMS Beagle took five years and went east to west, staying largely within the SE trade winds in the southern hemisphere. This is a favorite route for cruisers today, but not racers, who prefer to go west to east and stay in the roaring forties around Antartica.
Darwin and Alfred Russel Wallace (1823-1913)
• Darwin developed ideas on natural selection in early 1840s (1844 essay), but did not publish
• He received a letter from Wallace in 1858 outlining natural selection
• His friends organized an 1858 presentation in London of Wallace’s and Darwin’s work
• 1859 publication of Origin of Species
Darwin’s Theories of Evolution
Natural Selection• Individuals within species vary• Some variations are passed to offspring• More offspring are produced than can survive
(Malthus’ influence)• Survival and reproduction is not random.
Individuals that have favorable variations more often survive to reproduce, or reproduce more.
The Darwinian view of life has two main features
• the diverse forms of life have arisen by descent with modification from ancestral species
• the primary mechanism of modification has been natural selection working over enormous tracts of time
The Beagle in Sydney Harbor
Darwin’s Theories of Evolution
Common descent every group of organisms descended from a
common ancestor