evolution & pop. ecology

includes speciation, 5 fingers of evolution, and taxonomic hierarchy

genetic drift

fluctuations in allele frequencies due to randomness and chance events (i.e., bottlenecks)

⭐ decrease in genetic variation

gene flow

movements/migration of genes from one population to another (i.e., pollination)

⭐increases genetic variation.

mutations

a result of DNA replication errors and change in nucleotide sequence (i.e., insertion, deletion, etc).

⭐ increase in genetic variation.

assortative mating

individuals that mate with one another based on phenotypic similarities (i.e., female blister beetles choose mates that are similar to their size)

disassortative mating

individuals choose a mate based on phenotypic differences (i.e., Grey wolves will choose a mate with a different fur color)

inbreeding

individuals mate with others that have similar genetics to them or share a fairly recent common ancestor

inbreeding depression

a loss of fitness as homozygosity increases and heterozygosity decreases

sexual selection

females are the higher investment sex as they spend more energy in reproduction, therefore they have to be more selective w/mates. thus, males can have different traits that’ll make them appear more physically attractive to the female.

sexual dimorphism

the two sexes of a species will have a difference in traits as a result of sexual selection (i.e., peafowls look different than peacocks)

Carolus Linneaus

a Swedish botanist from the 1700s thats accredited for his use of binomial nomenclature and the taxonomic hierarchy of life.

Linneaus’ 2 Kingdoms

1) plants (nonmoving)

2) animalia (move around)

the three domains 

1) bacteria 

2) archaea 

3) eukarya 

taxonomic hierarchy

(Domain), Kingdom, Phylum, Class, Order, Family, Genus, Species

species

evolutionary independent group

biological species concept 

reproductively isolated individuals are different species 

prezygotic isolation mechanisms

circumstances that prevent mating (fertilization itself) that include: habitat, temporal, gametic, behavioral, mechanical

postzygotic isolation

circumstances that occur after a zygote has been formed such as reduced hybrid viability and hybrid breakdown

morphospecies concept

if they look the same, they’re the same species 

**some caveats w/this because you can have things like sexual dimorphism which doesn’t make creatures different species 

phylogenetic species concept

the study of an evolutionary history of a group i.e., how related are these certain individuals? **utilizes phylogenetic trees

phylogenetics

the study of the evolutionary history of life. includes both 1) phenetics and 2) cladistics

phenetics 

all traits are considered equally 

cladistics

only considers recent traits

monophyletic grouping

includes all of the descendants from a groups common ancestor

⭐subtype of cladistics 

paraphyletic grouping 

includes only some of the descendants of a common ancestor

⭐subtype of cladistics 

speciation

the creation of a new species that is based on isolation and divergence

allopatric speciation

geographic isolation (physical distance)

• dispersal: organisms intentionally migrate away from each other

• vicariance: change in landscape separates organisms

synpatric speciation

NO geographic isolation, organisms are still within proximity to each other. this mainly occurs due to organisms preferences for different habitats or foods (i.e., snakes in a similar area but one snake is aquatic and the other is terrestrial)

what happens when species come back into contact?

1) reinforcement

2) hybrid zones

3) new species via hybridization