Week 3 Flashcards
What’s fitness?
The reproductive contribution of a phenotype to subsequent generation related to the contribution of other phenotypes within the population.
Describe differential survival of offspring:
Most organisms produce a great number of offspring with different phenotypic characters. Those that survive and reproduce will prevale over popluation. If the traits are good the frequencies of allels that produce that phenotype will increase in the population.
Natural selection act directly on the___
Phenotype
Natural selection act indirectly on the___
Genotype
Describe continuous variation
There are no distinct categories and it’s quantitative. You have a range of values and it’s the result of a series of quantitative tratis influenced by alleles at many loci.
Describe discontinuous variation:
There are distinct categories and it’s based upon measure that can’t be put in a range (qualitative variation). It’s the result of quantitative trait influenced by alleles in a single loci.
What’s gene pool?
The sum of all copies of alleles at all loci found in a population.
What’s an adaptation?
A favored trait the evolve through natural selection.
What’s allele frequency?
proportion of each allele in the gene pool
What’s genotype frequency?
proportion of each genotype in the gene pool
What are the four process other than natural selection acting in nature?
1- Mutations
2- Gene flow
3- Genetic drift
4- Non random mating
Describe the mutation process in evolution
Is a source of genetic variation.
What are the three types of mutations?
Deleterious, neutral and beneficial
What’s gene flow?
Migrations of individuals and movements of the gametes between population can change allele frequency.
What’s genetic drift?
Random change of allele frequency in one generation to the next that changes allele frequency over time.
What’s non random mating?
Individuals mate preferentially with other individuals with one specific genotype.
What’s a neutral allele?
An allele that doesn’t affect the fitness of an organism
What’s a species?
A group of similar organisms that can interbreed to produce fertile and viable offspring.
What’s reproductive isolation?
Is a mechanism that restrict gene’s flow.
What are the three different geographic causes of speciation?
Allopatric speciation, parapatric speciation and sympatric speciation
What’s allopatric speciation?
A new species evolve because it’s geographically isolated from its ancestor. They’re separated by a physical barrier.
What’s parapatric speciation?
The new species evolve ina geographically contiguous population.
What’s sympatric speciation?
The new species evolve within the geogrpahic range of its ancestor.
What’s reinforcement?
Enhancement of reproductive isolation by natural selection.
