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What is convergent evolution?
Species that resemble each other even though they do not have a common ancestor.
In a cladogram, what is the outgroup?
The things used to compare to. It is closely related to the ingroup but not a member of it.
What is a shared primitive character?
The trait the outgroup possess. the first trait.
What is the unit that evolves?
What is a species?
A group of populations whose members can interbreed and produce fertile offspring.
What is a population?
A group of individuals of the same species living in the same place at the same time.
What are the conditions that must be mer for a population to be in Hardy-Weinberg equilibrium?
- The population is very large
- The population is isolated
- Mutations do not alter the gene pool
- Mating is random
- All individuals are equal in reproductive success
What is the equation for Hardy-Weinburg?
What are the three main causes of evolutionary change?
- Genetic Drift
- Gene Flow
- Natural Selection
What is genetic drift?
- A change in the gene pool of a population due to chance.
- The smaller the population the greater the impact.
What is the bottleneck effect?
An example of genetic drift. Natural disasters may kill large numbers of individuals producing a small surviving population unlikely to have the same genetic makeup as the original population.
What is founder effect?
The colonization of a new location by a small number of individuals. The smaller the group the less chance the genetic makeup will be representative of the large population they left.
What is gene flow?
A population gains of loses alleles when individuals move into or out of a population or when gametes are transferred between populations.
What is evolutionary fitness?
The contribution an individual makes to the gene pool of the next generation relative to the contributions of other individuals. The most fit ones are the one who produce the largest number of viable, fertile offspring and thus pass on the most genes to the next generation.
Why can't natural selection produce perfection?
- Organisms are limited by historical constraints
- Adaptations are often compromises
- Chance and natural selection interact
- Selection can only edit existing variation
Who was Jean Baptiste Lamarck
He influenced Darwin. he said that organisms interactions with the environment influences evolution. He was correct.
Who was Charles Lyell?
A geologist who influenced Darwin
Who was Thomas Malthus?
An economist who influenced Darwin.
Who was Alfred Wallace?
The guy who had the same ideas as Darwin.
What is macroevolution?
It encompasses the origin of new taxonomic groups, evolutionary trends. adaptive radiation and mass extinction
What is micro evolution?
A change in a population's gene pool over a several generations' evolutionary changes over a brief period of time.
What is speciation?
- Emergence of a new species
- Each time it occurs diversity increases
What is Hybrid in viability?
hybrid fail to develop or reach sexual maturity
What is hybrid sterility?
hybrids fail to produce functional gametes
What is hybrid breakdown?
offspring of hybrids are weak or infertile.
What are the 5 prezygotic reproductive barriers?
What is temporal isolation?
- two species breed at different times
- (different seasons, times of day, or even years)
What is behavioral isolation?
special signals attract males and elaborate mating behaviors are unique to a species.
What is the most important barrier?
What is mechanical isolation?
male and female sex organs are not compatible
What is gametic isolation?
mating may take place but zygote is not produced by gametes
What is habitat isolation?
two species live in same general area but not in same kinds of places
What is allopatric speciation?
a result of an ancestral population’s becoming insolated by a geographic barrier.
- •Mountain range may emerge and separate
- •Large lake may subside into many smaller
- lakes isolating fish populations
What is sympatric speciation?
A new species forms as a result of a genetic change that produces a reproductive barrier between the changed population (mutants) and the parent population.
Important in plant species.
Meiosis fails to occur properly. So one of the new cells is polyploid
What is adaptive radiation?
The emergence of numerous species from a common ancestor introduced to new and diverse environments.
What is gradualism?
Differences gradually evolve in populations as they adapt to their environment
What is punctuated equilibrium?
Abrupt episodes of speciation punctuating long periods of little or no change (equilibrium)