Ch. 22 Flashcards
Aristotle (384BC)
greek philosopher
arranged species on a Scala naturae
-viewed species as fixed
Carlous Linnaeous (1707-1778)
-Tried to organize all life forms using classifying system.
-Interpreted adaptation as evidence that the Creator designed each species for a specific purpose.
Lamarck
Darwin’s grandfather, suggested that evolution was a result of usage.
Wallace (1848)
came up with his own essay/hypothesis on natural selection
Darwin part 1
-published origin of species in 1859
-Fossils lay the groundwork for his ideas
-I perceived adaptation and origin of new species as closely related
-observed in Galapagos the environmental changes caused adaptations
Darwin’s 3 main observations
-unity of life
-diversity of life
-match between organism and environment
Darwin was influenced by…
Linnesaus
Lyell’s Principles of Geology
Thomas Malthus-
Artificial selection
selecting/breeding individuals with desired traits
Natural selection
-where organisms who better adapt to the environment tend to survive/reproduce
-found by Darwin
-increase/decrease heritable traits that vary in pop.
-doesn’t create new traits (just edits/selects for traits already present in pop.) -environment decides
-only mechanism that consistently causes adaptive evolution
Descent with modification
-all organisms are related through descent from a common ancestor
-can be viewed as a pattern/process
Darwins other main observations
-members of a population often vary in their inherited traits
-all species can produce more offspring than the environment can support, and many offsprings failed to survive
strata
layers
paleontology
study of fossils
Catastrophism
-each boundary between strata represents a catastrophe
James Hulton and Charles Lyell
- believed Changes in earths surface can result from slow continuous action still operating today
Uniformitarianism
-Lyell’s principle
-mechanisms of change are constant over time
-strongly influenced Darwin
-changes in the earth’s crust during geological history have resulted from the action of continuous in uniform processes
Niche
-job
-role an organism plays in a community
Evidence for natural selection
-response to introduced plant species
-drug-resistant bacteria
Homology
-Similarity resulting from common ancestry
-can form evolutionary tree
Homologous structures
similar physical features in organisms that share a common ancestor, but the features serve completely different functions.
Vestigial structures
Remnants of features that had function in organism’s ancestors
Evolutionary tree
-Hypothesis of relationships among different groups of species
-can be made by homologies and vestigial structures
Convergent evolution
-Evolution of analogous features in distantly related groups
-does not provide info on ancestry
-the independent evolution of similar features in species of different periods or epochs in time.
-ex. bat and insect both having wings and dolphin-like bodies
Analogous traits
-arise from groups independently adapting to similar environments in similar ways
-doesn’t mean relation when organisms have similar traits
