Download Early Ideas About Evolution

James Hutton (1726-1797)
 Scottish farmer and naturalist
 Considered the founder of modern geology as his ideas helped establish geology as a proper
science
 He believed that the Earth was continuously being formed and that an understanding of how the
processes of erosion and sedimentation work in the present day could lead to knowledge about the
history of the Earth
 Proposed theory called Actualism
 It states that the same geological processes occurring in the present also occurred in the past – this
is an essential principle of Uniformitarianism
Sir Charles Lyell (1797-1875)
 Built on Hutton’s ideas
 He was a British geologist
 Published the first volume of The Principles of Geology in 1830 in which he outlined many ideas
including that of Uniformitarianism
 Uniformitarianism (Gradualism) – the theory that the Earth’s surface has always changed and
continues to change through similar, uniform and very gradual processes
 Based theories on extensive examination of fossil deposits and such processes as erosion and
sedimentation
 This meant that the Earth was actually much, much older than most people believed
The work of Hutton and Lyell led to two significant conclusions:
1. The Earth must be ‘unimaginably ancient’
2. Dramatic change could result over such extremes of time through slow, slight processes
George Buffon (1707-1794)
 He was a French naturalist
 In 1749 he published the first volume of many of his famous work, Natural History
 Proposed that species could change over time and that these changes could lead to new
organisms; disagreed with Linneaus
 He suggested that similar organisms may have a common ancestor and in his attempts at
classifying organisms he tried to trace back to this common origin
Thomas Malthus (1766-1834)
 Published famous work, Essay on Population in 1798
 In this famous Essay, Malthus discussed his hypothesis that population growth that is unchecked
will always exceeds available resources, whereas actual population growth is kept in check with
food supply by a variety of factors such as floods, famine, disease, etc.
 He believed that actual population growth has a tendency to exceed available resources;
essentially believed that in nature, plants and animals produce far more offspring than are able to
survive
 Was an influence to Darwin in later years
Carl Linneaus (1707-1778)
 Was a Swedish botantist
 ‘Father of Taxonomy’ – he developed a system for classifying or grouping organisms
 This system included a hierarchical classification and custom of binomial nomenclature (genus,
species) which still exists today
 Proposed that relatively few species had formed many new species through hybridization and
interbreeding abandoning previous beliefs that species were fixed
Erasmus Darwin (1731—1802)
 Grandfather of Charles Darwin
 Published Zoonomia in 1794 where he proposed that all life may have a single source
Chevalier de Lamarck (1744-1829)
 Released his theory for how evolution occurs in 1800, and published his work in Philosophie
Zoologique in 1809
 New very simple species were being created by spontaneous generation
 Over time species increased in complexity until they achieved a sort of perfection
 He believed that in order for species to survive over long periods of time, they must be able to
adapt to changing environmental conditions
 Founded the principle of use and disuse – he believed that if an organ is used it would become
stronger and if it wasn’t used it would weaken and maybe disappear
 Where he went wrong: He stated that traits acquired from during one’s lifetime would be passed on
to offspring - ‘inheritance of acquired characteristics’
i.e. If a giraffe needed to stretch his neck to acquire food, then over the course of
his life his next would stretch and therefore having ‘acquired’ the trait of a longer
neck, he would pass it on to his offspring
Charles Darwin (1809-1882)
 Darwin was a naturalist, on a 5 year voyage on the HMS Beagle which travelled throughout the
Atlantic, around the coast of South America, through the Pacific, to New Zealand and Australia,
through the Indian Ocean and back to the United Kingdom
 It was one of the most influential voyages in human history
 Captain Robert Fitzroy’s primary mission was to survey and map coastal waters of South America,
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but he invited Darwin in hopes that he would find evidence to support biblical creation
Darwin’s role was to observe, record, and collect specimens of rocks, minerals, plants and animals
He suspected that many species bearing a striking similarity to other species, both extinct and
living, in the same region were related to one another
Darwin concluded that the origin of a new species arose from the gradual (generational) adaptation
to different environments
Gradual evolution meant that species descend from a common ancestor
He also drew inferences about evolutionary ancestors by comparing many features of organisms
(homologous, analogous and vestigial features)
Darwin’s theory was presented on July 1st, 1858 – he presented his theory along with another
naturalist who had come up with much the same conclusions, a man named Alfred Russell Wallace
In 1859, Darwin published his ideas in his most famous work called On the Origin of Species by
Means of Natural Selection or The Preservation of Favoured Races in the Struggle for Life
Alfred Russell Wallace (1823-1913)
 Wallace was a British naturalist
 He outlined an essentially identical theory of evolution by natural selection and sent it to Darwin to
have him evaluate the paper
 He presented his theory along with Darwin in 1858