BIO120 vocab terms

Sexual Dimporhism

differences in physical/phenotypic traits between males and females of the same species

Natural Selection

differences in fitness caused by differences in survival and reproduction in a particular enviroment

Sexual selection

differences in reproductive success caused by competition for mates

Anisogamy

production of 2 different sized types of gametes

Large gamete

eggs/ovules - the female gamete

Small gamete

sperm/pollen - the male gametes

Primary characteristics

Traits involved in producing 2 transmitting gametes

Secondary characteristics

non gamete development involved traits that develop at sexual maturity

Reproduction investment

contributes to the differences in dtrength and form sexual selection between the sexes

Which sex contributes the most energy to reproduction?

Females invest about 3000x more energy in gametes than males

Intrasexual selection

When individuals of the same sex compete for access to mates

Intersecual Selection

When mates (typically females) chose mates of the oppisite sex

Direct Benefit

Is when females chose a mate to gain a benefit such as territory, gifts, shelter, or protection

Nupital Gift

A type of direct benefit when the female gets something useful from a male as a gift, typically food

Sexy Sons hypothesis

When a female chooses a male mate because he’s attractive with hopes of better chance of their offspring reproducing

Runaway Selection

When a female prefers a specific trait, and when their male mate has that trait, their offspring has a more exaggerated version of that trait

Sensory Bias Hypothesis

When females already have a pre-existing preference that evolved, and the male trait evolves later to exploit it

Good genes Hypothesis

When a female chooses a mate with traits that indicate high quality genes to improve fitness in offspring

Gene flow

the movement of allele between populations, reduces genetic differences

Genetic drift

random changes in allele frequency, strongest in small populations

bottleneck

when populations experience a sudden reduction in abundance, genetic diversity is lost

founder event

when a few individuals establish a new population

stochastic evolution

random form of evolution such as mutation, recomination, or genetic drift

deterministic evolution

perdictible evolution such as natural selection

Low gene flow

Causes

• more unqiue polymorphisms

• more fixed differences

• genetically different populations

High gene low

Causes

• More shared polymorphisms

• genetically similar populations

Isolation by distance

as geographic distance increases:

• gene flow decreases

• genetic difference increases

Local adaptation

genetic differences evolved because different enviroments favor different traits

Phentypic plasticity

the ability of a genotype to modify its phenotype in response to a particular enviroment

Lamarck

First person to use evolution. The idea of inheritance of acquired characteristics

Heredity

Offspring resembling parents

adaptation

any trait that makes an organism fit

homology

the similarity in species due to a common ancestor

Darwin’s natural fitness

genetics (variation and heredity) and differential fitness

Mutation

the change in DNA during DNA replication

Recombination

When chromosome pairs swap during meiosis

Continuous traits

Quanitative genetics such as skin color, and envrriomental affects on phenotype

Discrete (Mendelian) Traits

Dominiant and recessive traits such as blood type and tongue rolling

Heterozygosity

Polymorphism