Test 1 Flashcards
What did Jean-Baptiste Lamarck propose?
Evolution occurs by inheritance of characteristics acquired by selective pressures
variation is acquired
What did Charles Lyell propose?
geologist that proposed uniformitarianism through the stratification of the earth’s core.
species appeared over time in the geological record, some disappeared and some modified
Alfred Wallace
developed theory of evolution through natural selection (independent of darwin)
published theories with Darwin
What is Wallace’s Line
Line between Bali and Lombok that separates the Asian Fauna from Australian Fauna
Charles Darwin
proposed that populations varied and those who were better suited to survive will pass their traits along
“On the Origin of Species”
Which animals were studied on the Galapagos
Land Tortoises
Darwin Finches
Blue-Footed Booby
Marine Iguanas
How did the Galapagos Islands allow for variation?
Islands varied in natural resources
Archipelago allowed for animals to be reproductively isolated
Natural Selection
individuals with certain alleles produce more surviving offspring than those without
increased allele presence over generations
Definition of “fitness”
measure by the number of surviving off-spring that are able to reproduce
Hardy-Weinberg Principle
genotypes will remain constant as long as
- population size is large
- mating is non-selective
- no mutations appear
- no selective pressures occur
- no im/emigration
Hardy-Weinberg Equation
p + q = 1
p - frequency of dominant allele
q - frequency of recessive allele
p^2 - homozygous dominant
2pq - heterozygous dominant
q^2 - homozygous recessive
Five Agents of Evolutionary Change
Mutation
Gene Flow
Nonrandom Mating
Genetic Drift
Selection
What is mutation?
change of an allelic proportion in a population
What is gene flow?
movement of alleles from one population to another
What is non-random mating?
mating based on a preference
inbreeding - > homozygosity
outbreeding - > heterozygosity
genetic drift
fluctuation of allele frequencies
founder effect
small population that turns into a large population quickly with out much genetic diversity
bottleneck effect
large population that decreases rapidly due to lack of genetic diversity
evolution definition
change in frequency of an allele in a population
Adaptive Selection Theory & polymorphism
animals with a common ancestor that adapted to different areas of a specific environment to avoid resource competition.
what is a transient species?
a transitional species that can allow for gaps in evolution to be explained
what is a punctuated equilibrium?
period of rapid speciation due to a change in environmental pressures
evolutionary change can be seen to move faster in smaller populations
Divergent Evolution (speciation)
evolution of different species of animals that can be traced back to a common ancestor
generally adapted to cope with new env. pressure
convergent evolution
organisms that are not from a common ancestor that independently evolve similar traits
analogous structures
features of species that are similar in function but not necessarily similar in structure / do not derive from a common ancestor
ex - flippers on dolphins and wings on penguins
homologous structures
features of a species that are similar in structure, but serve different functions / derive from a common ancestor
ex - human and dog limbs
artificial selection
favored traits that get selectively bred
vestigial structures
structures with no apparent function, but resemble ancestral structures
ex - leg bones in whales or snakes
importance of molecular record
species more closely related have more DNA similarities than those that are distantly related
Two Events necessary for speciation
reproductive isolation
genetic divergence
species definition
all individuals being capable of interbreeding and production fertile offspring
micro-evolution
change in allele frequency in a population that leads to a new species