darwin (theory of evolution) Flashcards
before darwin?
most viewed the world as incompatible with evolution, unchanging
aristotle?
recognized similarities among organisms and arranged life into linear sequence of increasing complexity
argument from design
argues that complex structure of living things and adaptations of plants/animals are evidence of intelligent designer
carl linnaeus?
developed taxonomic system where all organisms are arranged in hierarchical groupings based on similarity
–> believed it to be a divine plan
charles lyell?
geological processes must have operated over long periods of time in a slow, gradual manner
–> uniformitarianism opposed to catastrophism
uniformitarianism vs. catastrophism
uniformitarianism: earth’s crust was formed resulting from uniform, continuous processes
catastrophism: earth’s crust formed resulting from violent, unusual events (ex. the great flood)
erasmus darwin?
all life diversified over millions of years
–> humans initially walked on 4 limbs
georges curier?
established extinction through fossils
mary annings?
family collected/sold fossils, many findings were published with no mention of her
lamark’s theory
first detailed theory –> new, complex species descend from older, less complex ones
what book did darwin publish?
on the origin of species by means of natural selection
darwin’s 2 main arguments?
1) descent with modification
2) natural selection
what did darwin observe in the galapagos?
- species on different islands in similar habitats were distinct
- species on island were closely allied to forms on nearby continent
- fossil mammals in s. america that are extinct were similar to present-day species
what is transmutation?
changing of species
who did darwin work with for his book?
charles lyell, russell wallace
define descent with modification
all species have descended (with modifications) from 1+ common ancestors
–> change in characteristics over time
what is evolution
a change in allele frequency
(heritable character) in a population over time
what is a phylogenetic tree
diagram that represents evolutionary relationships among organisms
–> root = common ancestor, tips = extant species
what is the evidence of common descent
homology, vestigial structures, fossils, biogeography
what is homology
similarities in structure despite differences in function
–> similarity due to inheritance from common ancestor
–> structural, developmental
what are vestigial structures
remnants of structures that served a function in an ancestor
how do fossils prove descent with modification
demonstrates how species change over time
–> includes transitional species (bridge gaps between groups)
how does biogeography support descent with modification
living species tend to be similar to those geographically close
–> similar species are clustered in time/space
what is natural selection
traits that better enable a member to compete for limited resources will cause those who bear the trait to leave more offspring
–> trait will become proportionately more common in future gens
–> mechanism underlying evolution
critical factors for natural selection
- must be a fierce struggle for existence such that only a portion of offspring survive to reproduce
- success in struggle for existence is not random –> depends on traits facilitating it
- traits that increase success will become more common (evolution by natural selection
these conditions must be met for evolution via natural selection to occur
- individuals vary in traits
- non-random association between trait and reproductive success
- trait is heritable
what is tautology
a statement that is necessarily true by definition
what is fitness
measure of the capability of an individual to contribute to the next generation (reproductive success)
evidence for natural selection
- deductive reasoning (if necessary conditions are met, it’s the necessary outcome)
- consistent with observation that organisms are well suited to survive in their environ.
- analogy with artificial selection
what is artificial selection
evolutionary process in which humans consciously select for or against particular features in organisms
(T/F) Natural selection is goal driven and progressive
F
has no goal, is just a process
–> makes organisms better for CURRENT environ.
(T/F) natural selection doesn’t act ‘for the good of the species’
T
selection arises from variation in relative, not absolute fitness
–> often favours detrimental traits
what is evolutionary conflict?
when traits that maximize fitness in one individual are costly to another
what is creationism
belief that the universe originated from divine creations
–> NOT scientific, cannot be refuted
