lecture 34- population genetics and speciation

relative fitness

the contriubution an individual makes to the gene pool of the next generation relative to the contributiosn of other individuals

which of the followig is not like the other? gentic drift, found effect, bottleneck effect, gene flow

gene flow

what 3 ways does natural selection alter the allelic frequency?

directional selection

disruptive selection

stabilizing selection

what is the mechanism of evolution?

Natural selection

Directional selection

Shifts overall makeup of the population by favouring variants that are at one extreme of the phenotypic distribution

Disruptive selection

Favours variants at both ends of the phenotypic extreme

Stabilizing selection

Removes the extreme phenotypic variations from th population and preserves the intermediate types

Sexual selection

Individuals with certain inherited traits are more likely than others to obtain mates

Sexual dimorphism

Differences in secondary sexual characteristics between males and females of the same species

Intersexual selection

“Mate choice” individuals in one sex are choosy in selecting mates

Balancing selection

Maintains 2 or more phenotypic forms in a population

Frequency-dependent selection

The fitness of a phenotype depends on how common it s in the population

Heterozygous advantage

Heterozygous individuals have a great relative fitness than either of the homozygous individuals

heterozygous advantage is defined based on?

Genotype, not phenotype

Speciation

The process through which one species splits into 2 species

Micro evolution

Role of natural selection in the gradual adaptation of a population to its environment

Each time a species split, the new species share what?

Share characteristics of the common ancestors, homologous structures and divergent evolution

Each time a species splits, what can it result in?

Analogous structures and convergent evolution

Macroevolution

Is the broad pattern of evolution above the species level

Biological species concept

A species is a group of populations whose members have potential to interbreed in nature and produce fertile offspring

What does the formation of a new species depend on

Reproductive isolation

Morphological species concept

Classification of species based upon physical traits such as size and shape

Ecological species concept

Views a species in terms of its ecological niche, the sum of how members of the species interact with the nonliving and living things within its environment

Sexual selection can lead to what type of selection?

Direction selection

All the deviations from HW equilibrium we discussed cause the allele frequencies in a population to change, however all are not equal in their effect. Which is the greatest driver for micro evolution?

Natural selection

Which species concept does not require evidence of reproduction

Morphological species