Evolution yr2 sem1

what are analogies

traits that have evolved independently in different species but look the same - for example birds and bats have both evolved wings

convergent evolution

the type of evolution that produces analogies - two species evolving separately to have the same/similar trait

what are homologies

traits that are similar by evolutionary descent - they can look very different

i.e. humans, cats and whales have the same body plan for arms but they all look completely different

what is adaptive radiation

when an ancestral species rapidly diversifies into new species - occupying different ecological niches

how can we tell which traits are homologies and which are analogies

the comparative method

FLAG - CHECK THE PODCAST FOR EXPLANATION

what is a vestigial trait

traits that have lost their function through evolution

used to be useful and adaptive, not aren’t useful i.e. tail bones

what are behavioural vestigial characteristics

behaviours that used to be adaptive but are less so now

i.e. phobias - we have fears of snakes eventhough we have likely never come across a poisonous one before

explain ‘just so stories’ - Kipling

not plausible origin stories

stories made for children explaining where they got their traits from

i.e. elephants got their trunks because crocodiles pulled their noses

google exaptations

explain how traits can be a developmental byproduct

traits can arise as a byproduct of another trait being selected for

i.e. men have nipples because women have nipples and there is no pressure/reason for them to get rid of theirs

explain how traits can be maladaptive

they used to be adaptive, but are now harmful

i.e. our preference for sugary and fatty foods used to be adaptive when it was scarce, but now it is abundant it is making us obese

explain what phylogenetic inertia is

limits on what can evolve due to previous adaptations

i.e. flying pigs

not all traits can evolve because of physical constraints and our evolutionary history

what is Orgel’s second rule

Evolution is more clever than us as it can come up with unusual solutions to problems

i.e. platypus’ having a beak that can detect electrical signals in the water to locate prey

what does it mean for evolution to be ‘for the good of the species’

natural selection doesn’t favour species who kill themselves ‘for the good of the group’

it takes a gene’s eye view - killing yourself to relieve pressure for the rest of the group you don’t pass on your genes

explain the is-ought fallacy aka Hume’s Law

just because something did evolve, doesn’t mean we ought to act that way i.e. just because men evolved to be more aggressive than women doesn’t mean they ought to be

explain the naturalistic fallacy

just because something feels good doesn’t mean it is

‘goodness (morality) cannot be reduced to natural properties’

explain biological determinism

there is no biological determinism - our genes and evolution do not determine our fate

i.e. just because men are evolved to be more aggressive doesn’t mean they WILL be

explain the nature vs nurture debate

genes vs environment

they both influence traits so the argument is a false dichotomy and too reductionist

what is social spencerism

discusses societal evolution

economies and societies follow the same principles of natural selection - like survival of the fittest

name one way darwin’s idea has been misused

eugenics i.e. nazis

what is the EEA

Environment of evolutionary adaptedness

the EEA is the environment we have evolved in - specifically the african savanna (as we did 99% of our evolution here)

who coined the term EEA

Bowlby

What is adaptive lag

when adaptions can’t keep up with the changing environment - leading to traits that used to be adaptive, but now aren’t i.e. phobias

what are 4 core principles of evolution by natural selection

1. heritability

2. variability

3. surplus offspring

4. nonrandom survival and reproduction

give examples of evolution not due to natural selection

mutations

genetic drift

founder effect

mutual selection

criticisms of evolutionary psychology:

not very different from sociobiology

out of date understanding of evolution

give some key features of the behavioural ecology approach

ecology - how the immediate environment impacts us

optimality - the best possible solution given the environment

not interested in cognition

what is the goal of the behavioural ecology approach

to determine how differences between individuals can be explained due to optimality and fitness explanations

who studies the !Kung

DeVore

!kung is a tribe in tanzania who DeVore studied to see how ecology impacted their behaviour

how does the behavioural ecology approach use historical data

looks at birth records and birth rates

links with environmental information i.e. wars at the time to see how these impacted population levels

define obligate

having to act in a certain way in a certain environment

i.e. fish are obligately adapted to live in the sea

define adaptability

the degree to which a species can survive and reproduce in different environments

define niche

a niche is the environment and way of life of a species

greater overlap in niches leads to greater competition

what is optimal foraging theory

links to niches - considers the best strategy to survive i.e. if there are lots of animals in overlapping niches, maybe it is better to evolve to occupy a different niche.

examples of humans adapting to niches

1. sickle cell anaemia - developed as a resistance to malaria

2. the carpentered niche - humans living in a world of corners has lead us to develop an illusion where different lines represent inwards or outwards facing corners

behavioural ecology optimality card

adaptive trade-offs

explain what ultimate causation and proximate causation are

ultimate causation = evolutionary levels of explanation - explaining why a phenomenon exists

proximate causation = explains how a phenomenon works using immediate circumstances i.e. our genes or environment

what are Tinbergen’s 4 questions regarding how traits arise

ultimate (why questions)

1. function?

2. evolution?

proximate (how questions)

3. development?

4. causation?

1. function - look at podcast

2. evolution question

phylogeny (the study of our evolution to see connections amongst ancestors)

looking at the evolutionary history of a trait

3. development question

looking at the ontogeny (development) of a species to see where traits vary throughout development

4. causation question