Bio 172 Exam #2 Material

definitions and concepts since 1/26/24 reviewed in lecture

random genetic drift

an evolutionary process in which allele frequencies in a population change randomly over time due to chance events and has ability to reduce genetic variation, more pronounced in small populations

the four things random genetic drift does are

alters allele frequencies, reduces heterozygotes, leads to allele loss / fixation, non-adaptive evolution

life history evolution

a reason why species with strategies has a certain set of characteristics by taking into account statistics of fitness (lx and mx)

tools that help in developing life history

1) size of offspring (embryo/seed)

2) juvenile development time

3) age at maturity

4) size of maturity

5) size of offspring (environment / parents affect)

6) number of offspring

7) itero or seme / parous (repeated or single cycle of producing eggs)

8) post maturity growth

9) environment tolerance

10) dispersal mechanisms

11) parental care

generalists (k-growth)

organisms that can live anywhere with success for many years because they evolved to be durable (eg white tail deer, blue whale, elephants)

specialists (r-growth)

organisms that can only survive in certain conditions, temporary life spans in disturbed patches

Darwinian dolt / demon

natural impossibilities that will not occur in nature because natural selection will not favor the absurd life history characteristics they possess

phenotypic plasticities

features which can be expressed in certain environments

constitutive

always present phenotypic traits (like a rhino or porcupine)

what are the four reasons for the phenotypic plasticity of these adaptations

1) requires carbon investment

2) feature is not always necessary

3) benefit in certain environments

4) only evolve if there is a reliable cue