chapter 19
the scala naturae
the greek philosophers fixed ladder of complexity of organisms
humans naturally at the top, and invertebrates on the bottom
Carolus Linnaeus
founded taxonomy
while god created things, Linnaeus classified them
fossils
laid groundwork for darwin
found in sedimentary rock layers, strata
classified by the chronologized layers of earth
Georges Cuvier
french naturalist in the 18th century
developed paleontology
advocated catastrophism suggesting that each layer of the earth represented a catastrophe in history
was cancelled because he suggested there were more catastrophes in earths history than Noah's ark needed to explain the diversity of life
james hutton
scottish geologist in the 16th century
along with Lyell, perceived that changes in earths surface can result from slow, continuous processes that still operate today
challenged the church by developing the concept of deep time, or geological time so he also got cancelled
Charles Lyell
english geologist
along with hutton, perceived that changes in the earths surface can result from slow, continuous processes still operating today
principle of uniformitarianism
uniformitarianism
mechanisms of change are constant over time
strongly influences darwin
developed by charles lyell
jean-baptiste lamark
first evolutionist
hypothesized that species evolve through use and disuse of body parts and the inheritance of acquired characteristics
his work was not exactly correct so he's largely disregarded, but he was on the right track
descent with modification
explains the adaptations of organisms and unity and diversity of life
charles darwin was born
february 12th 1809
as a kid darwin was
always interested in nature and animals
darwin started his education at
university of edinburgh for medicine
darwin finished his education at
cambridge university studying theology
captain robert fitzroy
captain of the HMS Beagle
principles of geology
written by charles lyell, influenced darwin on his journey on the beagle
the galabagos archipelago
islands where beagle spent 5 weeks
home of the galapogos finches
galapagos finches
helped darwin establish the environmental adaptations organisms make
the origin of species
published 1859 by Charles Darwin
explains 2 major ideas
1) descent with modification explains the unity and diversity of life
2) natural selection is the cause of adaptive evolution
descent with modification
veiw that all organisms descended from a singular common ancestor
phylogeny trees
represent tree of life
branches represent modification in the organism ie a new species
alfred russell wallace
came up with the same theories as darwin just later on, so their work was published at the same time so to not discredit one another
father of biogeography
darwin and artificial selection
darwin examined how farmers created desirable crops and animals and experimented himself with pigeons
the 4 observations that lead to darwins theory of natural selection
1. populations have diverse traits
2. traits are inherited
3. species are capable of creating more offspring than what the environment can support
4. because of the lack of support from the environment, many excess offspring die off
the 2 inferences that lead to darwins theory of natural selection
1) individuals with favorable traits survive and reproduce more
2) the unequal distribution of survival leads to desirable traits prevailing over others
thomas malthus
noted the potential of humans to increase population faster than the environment could keep up
darwin took this idea
the process of adaptation
if some heritable traits are advantageous, they will accumulate in a population and become frequent in individuals in that population
the match between organisms and their environment can be explained by
the process of adaptation
rules for evolutionary change
1) individuals must vary in reproductive success
2) some variation in the trait must be heritable
3) trait must be correlated with reproductive success
individuals do not evolve t or f
true
populations evolve over time
darwins theories according to mayr
1) evolution
2) common descent
3) multiplication of species
4) gradualism
5) natural selection
which theory was darwin partially wrong about
gradualism
a theory
a well verified explaination based on a body of facts that have been well tested
explains why something happens
a law
more algorithmic than a theory
explains how something happens
what does a theory do
makes life easier for scientists
compresses the data of the world
what are the 4 lines of scientific evidence for evolution
1) evolution is directly observable
2) homology
3) fossil record
4) biogeography
vestigial structures are an example of
homology
the trinidad guppies helped show what
evolution is directly observable
continental drift is an example of what
biogeography
convergent evolution
an example of homology
evolution of similar or analogous features in distantly related groups