History of Evolutionary Thought PDF

**Aristotle (384-322 B.C.)** - He believed organisms are fixed and unchanging - Scala Naturae (ladder of nature) - Simple organisms at the bottom wrung **Strict Biblical View** - All life is a creation of God and therefore perfect - Organisms do not change - Adaptations to environ...

**Aristotle (384-322 B.C.)** - He believed organisms are fixed and unchanging - Scala Naturae (ladder of nature) - Simple organisms at the bottom wrung **Strict Biblical View** - All life is a creation of God and therefore perfect - Organisms do not change - Adaptations to environments are viewed as God's cleverness - This view along with aristot;es ladder prevailed for almost 2 millennia Fossils - Not studied until the 17-1800s **George Cuvier   (1762-1832)** - French paleontologist (the first paleontologist)     - noted that fossils in deeper strata were more dissimilar to extant (existing) creatures than those in newer strata  \- some fossil creatures disappeared in newer strata  His conclusion: Catastrophism- the Earth has largely been shaped by sudden, short-lived, violent events, possibly worldwide in scope **James Hutton (1726-1797) Scottish Geologist** - Thought gradual processes can lead to big changes, given enough time Gradualism - change is the cumulative product of slow but continuous processes **Charles Lyell (1797-1875) Scottish geologist** - Geological process that operate now are the same as those that operated in the past and they operate at the same rate now as they did then  Uniformitarianism - the assumption that the same natural laws and processes that operate in our present-day scientific observations have always operated in the universe in the past and apply everywhere in the universe. - Both this and gradualism argue against "young Earth: **Carolus Linnaeus (1707-1778) Carl von Linne     **    - Swedish botanist, father of modern taxonomy - Contradicted aristotle's ladder in that he nested organisms grouping similar organisms into categories  - Kingdom, phylum, class, order, family, genus, species (genus + spp=binomial nomenclature)  - Similarities represented God's pattern (not shared ancestry- that did not occur to him) **Georges- Louis LeClerc, Comte de Buffon (1707-1788)** Brought up the concept of species changing over time - Species "improved" or "degenerated" after dispersal from point of creation  Developed "unity of type" - Precursor of comparative anatomy  Responsible for acceptance of "Old Earth" - 75,000 years old  Later in life he wrote about the immutability of species  **Jean-Baptiste de Lamarck - French naturalist (1744-1829)** - Noted adaptations to environments - Proposed that gradual change could explain the fossil record  - Recognized several evolutionary "lines" - Proposed how species change **Suggested that organisms evolve through** - Use and disuse - Inheritance of acquired characteristics  Ridiculed in his own time, especial by Cuvier who thought that organisms did not change (but just died and appeared) **Thomas Malthus (1766-1834) british teacher, economist, ANglican curate** - 1798 essay on "the principle of population"  - Human pop. will grow faster than available resources - Leads to a struggle for survival - Only the best will/should survive (he was against government welfare which, he thought, only created more poor people) **Erasmus Darwin- charles darwin's grandfather (M.D., philosopher, inventor, poet) (1731-1802)** - Believed in the possibility of passing traits to offspring (before Mendel was even born...) - Thought all creatures came about from one organism and that the organisms change by adopting to their environments and passing on genetics to offspring **Charles Darwin**- Born February 12, 1809, English, loved nature, Dad was a doctor sent him to Med school at 16 - Bachelors in Theology from Cambridge  - In 1831, joined the Beagle as a companion for Captain FitzRoy (as ship\'s naturalist too) Voyage of the Beagle - 5 years- visited South America mostly - Noted:  - Adaptations to diverse environments - Temperate South American species resembled tropical South American species more than they resembled temperate European species  - Fossils from South America resembled living South American organisms more than European fossils  - Each continent had its own species - Witnessed geology at work  Galapagos Finches Charles Darwin's hypothesis: Galapagos Islands were colonized by a South American species which then adapted to local environmental conditions- over time they changed so much, that they could now be considered different species  His Thoughts - by the early 1840's worked out the theory of Natural Selection Natural Selection- the mechanism of evolution (how it happens) - Heritable variation exists in populations  - Organisms produce more offspring than can possibly survive  - Those with favorable traits that help them survive in their environment will survive and reproduce better than others  - This differential survival and reproduction will result in the accumulation of favorable traits in the population  Alfred Russell Wallace Journey- Brazil and Indonesia  \*June 1858 Wallace had also came up with Natural Selection  \*July 1,1858 Lyell presented a paper on Chuck's work to the linnaean Society of London Major principles of On the Origin of Species... - Species inhabiting the Earth now are descendants of ancestral species that were different  - Known as "Descent with Modification"  - Mechanism of change is Natural Selection  Theory- colloquially it is a hypothesis, scientifically it is a broad explanation of a natural phenomenon that is based on extensive evidence, and has been tested multiple times by multiple independent researchers, and not yet found to be false