BIOL1003 Lecture Notes - Stabilizing Selection, Adaptation, Coevolution
Inspecting Natural Selection
NO natural selection is a syllogism
•If [ajo peises] ou
•The etai oseuees ust e tue
•Test falsifiatio of ajo peises
Evolution by Natural selection a definition
If a population has a. Variation in a trait among individuals (replicating units) b. A consistent
relationship between that trait and fitness (survival, mating, fecundity) c. Heritability (parents
resemble offspring at least partly unrelated to their common environment) Then 1. There are
differences between individuals that are born and those that breed (within-generation effects) 2. If
the population is not at equilibrium, there are predictable differences between parents and offspring
(between-generation effects)
What things can be naturally selected?
Thik of ods: Copied fo oe peso to the et. “oetie utate –I ask, but some people
aks.
Question: What is the analogue of genotype and phenotype when it comes to, say, language or
memes (ideas)?
This is quite a trick uestio….
Fitess : the epodutie suess of a idiidual ith a patiula pheotpe •Copoets of
fitness: – Survival to reproductive age – Mating success – Fecundity
•‘elatie fitess: fitess of a geotpe stadadized opaiso to other genotypes
The sum of all allele frequencies is 1 p + q = 1.0 In Hardy-Weinberg equilibrium, the genotype
frequencies are always: homozygote dominant = p2 heterozygote = 2pq homozygote recessive = q2
The sum of all genotype frequencies is 1 p2+ 2pq + q2= 1.0 Frequency of each genotype (& allele)
The sum of all allele frequencies is 1 p + q = 1.0 In Hardy-Weinberg equilibrium, the genotype
frequencies are always: homozygote dominant = p2 * Wpp heterozygote = 2pq * Wpq homozygote
recessive = q2 * Wqq The sum of all genotype frequencies is 1 p2+ 2pq + q2= 1.0
Contribution of alleles to fitness
•Aeage eess fitess of a allele:
difference between average fitness of individuals with allele vs. those without
Fitess otiutio of heteozgotes ad homozygotes for the allele, how many individuals of each
ae peset ad ho a offspig eah otiutes to the et geeatio
diffeee etee aeage fitess of idiiduals ith allele s. those ithout Δp = p aA/ϖ)
P t+1 = p t ( 1 + (aA1/ϖ))
Evolution by natural selection a definition If a population has a. Variation in a trait among individuals
(replicating units) b. A consistent relationship between that trait and fitness (survival, mating,
fecundity) c. Heritability (parents resemble offspring at least partly unrelated to their common
environment) Then 1. There are differences between individuals that are born and those that breed
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
No natural selection is a syllogism: if [(cid:373)ajo(cid:396) p(cid:396)e(cid:373)ises] o(cid:272)(cid:272)u(cid:396, the(cid:374) (cid:272)e(cid:396)tai(cid:374) (cid:272)o(cid:374)se(cid:395)ue(cid:374)(cid:272)es (cid:373)ust (cid:271)e t(cid:396)ue, test (cid:271)(cid:455) falsifi(cid:272)atio(cid:374) of (cid:373)ajo(cid:396) p(cid:396)e(cid:373)ises. Thi(cid:374)k of (cid:449)o(cid:396)ds: copied f(cid:396)o(cid:373) o(cid:374)e pe(cid:396)so(cid:374) to the (cid:374)e(cid:454)t. o(cid:373)eti(cid:373)e (cid:858)(cid:373)utate(cid:859) i ask, but some people (cid:858)aks(cid:859). Fit(cid:374)ess (cid:894)(cid:449)(cid:895): the (cid:396)ep(cid:396)odu(cid:272)ti(cid:448)e su(cid:272)(cid:272)ess of a(cid:374) i(cid:374)di(cid:448)idual (cid:449)ith a pa(cid:396)ti(cid:272)ula(cid:396) phe(cid:374)ot(cid:455)pe co(cid:373)po(cid:374)e(cid:374)ts of fitness: survival to reproductive age mating success fecundity: elati(cid:448)e fit(cid:374)ess: fit(cid:374)ess of a ge(cid:374)ot(cid:455)pe sta(cid:374)da(cid:396)dized (cid:271)(cid:455) (cid:272)o(cid:373)pa(cid:396)iso(cid:374) to other genotypes. The sum of all allele frequencies is 1 p + q = 1. 0 in hardy-weinberg equilibrium, the genotype frequencies are always: homozygote dominant = p2 heterozygote = 2pq homozygote recessive = q2. The sum of all genotype frequencies is 1 p2+ 2pq + q2= 1. 0 frequency of each genotype (& allele) P t+1 = p t ( 1 + (aa1/ )) Evolution by natural selection a definition if a population has a. Variation in a trait among individuals (replicating units) b.
