Natural Selection PDF

1 Natural selection 23 Tuesday, 3 October 2023 1 Natural selec,on 23 10:48 Expects to be working beyond material - read r the lectures Teleology means with a purpose or aim, selection is not Important Result of adaptive radiation in cichlids Ecology is the study of...

1 Natural selection 23 Tuesday, 3 October 2023 1 Natural selec,on 23 10:48 Expects to be working beyond material - read r the lectures Teleology means with a purpose or aim, selection is not Important Result of adaptive radiation in cichlids Ecology is the study of the relationships betw including humans, and their physical environm Ecology is the study of the relationships betw including humans, and their physical environm lines ) Natural selection is on the individual, not ent members of species are individuals largest co He lacked understanding of genetics Darwin's finches - Big beaks eat small and big seeds - Small beaks eat only small seeds - Small beaks eat only small seeds If a drought comes small seeds favoured and he dwindle and hence small beak birds die. Average size of beak increases due to little The passing on of beak size after the other and new birds mated is called evolution, as John Endlers definition, has conditions and result of these condi - Population has variation in a trait There are lots of variation across the world Continuous like height or not like flower colour polymorphisms Also variation in DNA, genetic variation. Also variation in DNA, genetic variation. Next condition - Consistent relationship of this trait with fitness of an organis reproduction. The mass is negative in fig c as its relative to the mean. Difference in survival and fitness based on traits Next condition is that trait must have relationship with parent ( tr Which many don’t agree with. Calculate what proportion a fraction of total phenot phenotypic ) Called narrow The heritability is the additive genetic variance / total v variance = additive + year + brood + residual. How is this calculated? - Francis Galton Relationship of height Slope = heritability = 0.69 = 0.69 similarity of parents and o Slope = heritability = 0.69 = 0.69 similarity of parents and o Heritability will always be below 1 as that’s impossible to ha You expect average height in population regresses towards true if variation was continuous - However it doesn’t due to recombination shuffling ar Result of these conditions - Trait frequency distribution will differ amongst age - Population not in equilibrium there is a shirt in trait freque Process with orangutans in Borneo Variations in forearm limb length ( the trait ) Trees cut down so small forearms cant reach trees and they fall o On average orangutans now have longer forearms But relationship when orangutans have babies isn't 1:1 due to re increases again. So now when babies are born, they are a bit larger than average their parents who were the ones who survived. ( long limbed ) Due to recombination of genes and this still leading to smaller lim Natural selection isn't evolution. When looking at data do 2 step process 1. Break down overall pattern and identify - u can see pattern understanding 2. What does this mean biologically - consequences and the w