Mutations

Mutations as a mechanism of evolution

Mutation

Changes to DNA

Spontaneous Mutation

occurs naturally without external influence, often due to errors in DNA replication or repair.

Induced Mutation

Mutations occurring from external influence

Sexual Selection

Selection that favours sexually appealing traits that aren’t necessarily advantageous to survival

Sexual Dimorphism

The difference in traits between sexes

Stabilising Selection

Selects against deleterious alleles in a stable environment, favoring the optimal phenotype for that environment gradually.

Directional Selection

Changes to environment leading to selective pressures that favors more extreme traits over neutral traits.

Disruptive selection

favors multiple diverging extreme traits, leading to two peaks of common traits.

VESIG

Variation, Environment, Selection, Inherit, Generation

Variation

The different phenotypes in the population

x has had variation in their y gene

Environment

the environment decides the desired traits for survival

what was the change and why was the trait more favorable

Selection

Selective pressure; environment, predation

what makes this gene more survivable

Inherit

Favorable alleles are inherited from parents to offspring

x is passed generationally, overtime these alleles become more common

Generations

Over generations, certain alleles are favored and increase, while unfavorable ones decrease.

Genetic Drift

Random changes in small populations

bottleneck effect

Sudden reduction of a large populations from a catastrophic event. Surviving genes will be found often even after population has recovered.

founder effect

small groups of individuals migrate and establish population in a new location.

gene flow

migrants between isolated populations breed, adding or removing genes.

micro evolution

changing the frequency of various alleles within a population. changes to the gene pool of a population for any reason.

macro evolution

major evolutionary changes affecting many species, resulting in multiple species being affected

speciation

the diverging of a species into different species

adaptive radiation

a species giving rise to new group of organisms comprising of new species, generally after mass extinctions or major changes in the environment.

nonsense mutation

mutation that causes nucleotide substitution to create a stop codon, terminating the translation of that protein.

allele frequencies

the frequencies of alleles will change over time in response to various evolutionary processes.

Principles of Evolution

adaptive evolution through natural selection

adaptive evolution

unequal chances of reproduction lead to the accumilaton of favorable alleles

Natural selection

changes the allele frequencies within a population, favoring ones with better survivability and resulting in fewer diversity of alleles

species

1 natural selection favours specific phenotypes to adapt to the environment (microevolution)

2 speciation - population accumilates so many changes they can be identified as seperate species

3 macroevolution - many speciation events result in development of new genera taxa

taxa

broader classification of a group of many species that have specific traits distinct to other groups of species

evolution

the appearance and disappearance of species over time, through natural selection

species

genetically isolated group that who are able to interbreed and produce fertile, viable offspring only with other members of that group

morphological framework of species

defining and identifying species based on their physiological and physical features, used generally with fossils