evolution Flashcards
What was Darwin’s research?
-Visited Galápagos Islands (1835)
-Lots of endemic species (species local to area in isolation)
-Mockingbird appearance differed depending on island that they were on
-Took a sample and wanted to research more
Define functionalism
-Characteristics of organism have useful function
-Important to survive
-To understand how it occurs, we need to know why it occurs
Define natural selection
-Differences seen within species
-Favourable characteristics can passed through generations
-Mutations can occur
-Drives adaptive radiation
Define adaptive radiation
-One species that evolves rapidly into multiple different species in order for survival
-Goes to food resource where there isn’t much competition, so creates differences in their appearance
-E.g. Darwins finches
When did human evolution begin?
-First hominoids, which are human like apes, first were shown in Africa
-Got away from Africa around 1.7 million years ago
What is the development like for human evolution?
-Relatively late development, around 60 million years ago for primates
-Rapid evolution of human brain and behaviour
What are our closest living relatives?
-Chimpanzees, gorillas and orangutans
-DNA = small amount of difference
-Humans and chimpanzees share 99% of DNA
What are the useful functions for humans?
-Bipedalism = allows mobility, energy efficiency when travelling etc.
-Opposable thumbs = agile hands for hunting and gathering
-Colour vision = useful for humans to see between leaves and fruit etc.
-Linguistic abilities = share information and propagation of species
What did Herculano-Houzel et al. (2007) find?
-Compared human brain weight and number of neurons
-Found primates have the most neurons
-Changes in neocortex size compared to other non human animals
Define neoteny
-Slowing of maturation
-Allows growth
-Important for developing large brain and complexity
Why should we study non-human species?
-Similarities allow understanding link between brain and behaviour
-Comparisons can see advantages between species
What did Maren et al., (1997) find?
-Looked into hippocampus lesions in rats
-Found impaired conditioning to contextual cues
What did Clayton (1998) find?
-Used birds
-Found that the hippocampus regions was enlarged in the food storing species
-This is because they have to remember where they stored the food and how they have to get there = links to memory
-Also found that the hippocampus can change size based on experience
What is the game theory?
-Von Neumann and Morgenstem
-Typically a mathematical model of strategic decisions
-Analysing outcomes based on decisions
What did Maynard Smith and Price suggest?
-Applying game theory to look at evolution strategies
-Evolutionary Stable Strategies (ESS)
-Best strategy for survival
-Your strategy should do better than any other one
-Should have more comparable benefits
What is the Hawk-Dove game?
-Looks into cooperation vs conflict
-Hawk + Hawk = fight for resource and winner gets it, cost of injury
-Hawk + Dove = hawk dominates
-Dove + Hawk = hawk dominates
-Dove + Dove = both passive and share
What is the Prisoner dilemma?
-2 people get arrested for the same crime
-Unable to communicate with each other
-They have 3 options of what they can do to determine which sentence they receive
What are the 3 options in the prisoner dilemma?
1: Both stay silent + get 1 year each
2: One implicates other which they stay quiet + betrayer is free and silent player gets 5 yrs
3: Both implicate each other + each get 3 yrs
What would be the best strategy in this scenario?
-Best strategy for mutual benefit = is both staying quiet
-Best strategy for individuals = confessing and implicating each other
-Overall, if you don’t know the other persons strategy then you should confess and implicate
What did Axelrod and Hamilton suggest?
-Tit for tat strategy
-Used computer simulation
-Cooperation emerged as ESS when probability of both individuals meeting was high
-If you meet the person before then go with the mutual benefit strategy
-Mutual benefit is better strategy then more time you meet and the more arrests you have
Define altruism
-Fehr and Fischbacher (2003)
-Behaviour at a cost to oneself but is then a benefit to other people
Why would you show altruism towards relatives?
-Inclusive fitness
-Hamiltons rule
Define inclusive fitness
-Includes direct fitness = offspring of an individual
-Includes indirect fitness = offspring in same species
What is Hamilton’s rule?
-rB > c
-r = genetic relatedness
-B = benefit
-c = cost)
Define non-kin altruism
-Defines why we help strangers
-Reciprocal altruism
-Group selection
Define reciprocal altrusim (Rivers, 1971)
-Helping someone because you think they will then help you in the future
-Benefits are reciprocated
Define group selection
-Cooperation
-Helps to dominate selfish groups
-Humans giving to charity
