Aristotle Carolus Linnaeus Comte De Buffon Erasmus Darwin

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Aristotle Carolus Linnaeus 384 – 322 BC 1707 – 1778 AD

• Greek philosopher “The father of modern taxonomy” • Examined nature world for evidence • Classiﬁed organisms with a binomial of divine order system • Scala naturae (“Chain of Being”) • Hierarchical arrangement of forms • Proposed a nested system of relationships (as opposed to the Scala naturae) • Species arranged linearly along a scale: God • Recognized distinction between interbreeding vs. non- Man interbreeding organisms (same vs. different species) Mammals Egg-laying animals • Believed in balance of nature Insects Plants • Each species has its place in a divine plan Non-living matter • Species do not change or go extinct • formed the basis for the western belief in a ﬁxity of • Eventually acknowledged formation of new species by species, each of which has a typical form hybridization

Comte de Buffon Erasmus Darwin 1707 – 1788 AD 1731 – 1802 AD

“Dégéneration” • Believed life & species arise via material processes Charles’ Grandfather • Looked for evidence in the physical & biological world • British philosopher, naturalist & physician • Believed Linnean hierarchy reflected common descent • Wrote Zoonomia: Or The Laws of Organic Life (dégéneration), with divergence over time. • Believed organisms constantly attempted to improve • Physical environment (somehow) changes organic particles themselves by adapting to their environment • New species form when animals migrate, and new • Transformism, or transmutation environment changes them • All of life consists of “one living filament” connecting all • Change only happened within families: each family living forms to a common ancestor conforms to an internal mold, but species can change some over time. Jean-Baptiste Lamarck Thomas Malthus 1744 – 1829 AD 1766 – 1834 AD Principle of overproduction Inheritance of acquired characters • English clergyman • French professional naturalist • Major influence on Darwin & Wallace • Theory of transformism • Essay on the Principle of Population (1797) • “Simple” organisms constantly arise by spontaneous • Most organisms produce far more offspring than can possibly generation survive • Organisms then progress through a hierarchy of ever- • Even when resources are more-advanced forms (Scala naturae in reverse?) plentiful, populations tend to • Philosophie zoologique (1809): grow geometrically until they • First law: Use or disuse of a structure leads to its outstrip their food supply development or diminishment • Poverty, disease, and famine are • Second law: These acquired characters can be passed inevitable, leading to a “struggle on to offspring for existence”

Charles Lyell Charles Darwin 1797 – 1875 AD 1809 – 1882 AD Uniformitarianism • English geologist • Another major inﬂuence on Darwin & Wallace • Believed earth is constantly changing The Man • Processes that molded earth’s surface can be understood by • An English “gentleman of private means” modern-day processes • Was able to focus on his life’s work: the development of • Uniformitarianism: earth is subject to gradual, the theory of evolution by natural selection continuous change • But there is no development or progress: earth remains at a steady state – in particular, species composition doesn’t change Charles Darwin Charles Darwin 1809 – 1882 AD 1809 – 1882 AD The Voyage of the Beagle (1831–1836) Biogeography on the Beagle • Noticed that two similar species often coexisted in a “boundary zone” – neither one better adapted than the other • These species must compete with each other

For example: The rhea, a ﬂightless • Read Lyell’s Principles of Geology while on board (and correctly bird in South America applied the principle of uniformitarianism to the formation of coral reefs) • Developed an appreciation of biogeographical patterns

Charles Darwin Charles Darwin 1809 – 1882 AD 1809 – 1882 AD Biogeography on the Beagle Biogeography on the Beagle • Why do different groups of organisms live in • Why do different groups of organisms live in areas separated by barriers (like the ocean)? areas separated by barriers (like the ocean)?

Why are the rhea and the ostrich so different, On the Galapagos Islands, even though they have Darwin noted that even islands similar lifestyles under that were very close together similar circumstances? had giant tortoises that were distinct from one another Would a creator be limited by boundaries to migration? Charles Darwin Charles Darwin 1809 – 1882 AD 1809 – 1882 AD Back in Britain: The origin of species The theory of natural selection • As natural selection acts on geographically • Darwin recognized several critical facts: isolated populations, they become • Variability exists within species increasingly different from each other • Variant traits may be inherited (Darwin didn’t know how) • Malthus’s Principle of Overproduction implies that many • This leads to the individuals must die or fail to reproduce formation of ﬁrst • Individuals slightly better suited to their environment varieties within a must be more likely to survive species, then separate • Therefore, some variants will be preserved over time species, then genera, etc., in an ever- more than others. The composition of populations branching process. must change over time.

Alfred R. Wallace 1823 – 1913 AD Image credits Natural selection co-discovered • English professional naturalist • In 1858, sent a letter to Darwin Aristotle: www.columbia.edu/cu/philosophy/ admissions/text/process.html Linnaeus: www.nhm.ac.uk/library/linn/ describing his independent discovery of Buffon: www.ucmp.berkeley.edu/history/buffon2.html Erasmus Darwin: science.ntu.ac.uk/erasmus.html natural selection Lamarck: www.biol.unipr.it/aai/galleria/lamarck.gif Malthus: homepages.caverock.net.nz/~kh/bobperson.html • Like Darwin, travelled around the world observing Lyell: athene.as.arizona.edu/~lclose/teaching/nats102/lyell.gif biodiversity and biogeography Charles Darwin: www.nirgal.net/ori_life1.html Beagle map: www.aboutdarwin.com • Like Darwin, he’d read Lyell and Malthus, and Rhea: www.sc.edu/library/spcoll/nathist/darwin/rhea.jpg Ostrich: www.uct.ac.za/depts/ﬁtzpatrick/docs/research.html eventually realized that “[the] self-acting process [of natural Tortoise: www.sandiegozoo.org selection] would necessarily improve the race, because in every Wallace: www.d.umn.edu/cla/faculty/troufs/anth1602/pchistory.html generation the inferior would inevitably be killed off and the superior would remain – that is, the ﬁttest would survive.”