Lecture 13- Evolution Flashcards
What are the 2 core concepts of evolution?
Darwin’s theory
Natural selection
What is Drawin’s theory of evolution?
Visits Ecuador with high number of endemic species and notices mockingbirds differed between islands. -Suggests functionalism exists in which characteristics of an organism has useful function for survival
what is natural selection?
Differences are seen within species and can be inherited, favourable characteristics that help survival/reproduction are passed down and become dominant. Drives adaptive radiation
What is adaptive radiation?
Single species evolves into multiple new to match survival eg different beak shapes for different food types.
What happened in the process of human evolution?
Earliest mammals were small nocturnal predators that fed on insects.
-Considered a late development as rapid evolution of brain and behaviour sets us apart from other animals.
How much DNA do humans and chimps share/
Humans and chimpanzees share almost 99% of their DNA
What does brain evolution suggest?
Size of brain does not matter, only neurons and brain complexity are key
What did Herculano-Houzel et al (2007) say about brain evolution?
Found brain weight to number of neurons, found primates to have most neurons. -Neurons coded for useful function and cognition through Neoteny.
What is Neoteny?
Slowing of maturation, allowing for time for growth, important for large brain and complexity. -Not all neurons are coded at birth, allowing for learning based on environment
What are the 4 human functions and definitions?
Bipedalism – Mobility, energy efficiency and adaptability.
Opposable thumbs – Agile hands for tool use.
Colour vision – Differentiate fruits from leaves, fruit decay. Linguistic abilities – Sharing information, propagation of species.
What is the importance of animal models?
-Hippocampal lesions in rats -Impaired conditioning to contextual cues -Amnesia in humans with hippocampal damage -Rat studies tell us which neuronal systems are key
What does Clayton (1998) say about importance of comparative studies?
Found unique source of evidence for role of hippocampus as within birds/mammals the hippocampal volume is enlarged in food storing species suggesting hippocampus can change size in response to experience.
What does Von Neumann + Morgenstern say about game theory in evolution shaping
Mathematical model of strategic decisions. Analysis of outcomes based on own and other decisions. No control over other’s decisions.
What did Maynard Smith + Price say about evolution shaping?
Applied in understanding evolution strategies. Evolutionary stable strategies (ESS) and price equation.
What does the Hawk/dove game say about cooperation vs conflict?
Hawk=aggressive, take by force Dove= Passive and will avoid conflict Both encounter a food resource of 1 and have benefit of acquiring resource and cost of fighting/risk of injury.
What does the EES suggest is best strategy for dove/hawk game?
-Strategy should do better with itself than any new competing strategy if it tried to invade -Strategy should have at least comparable benefit than any other strategy.
What is the prisoner dilemma?
Prisoner 1 and 2 arrested for same crime and interrogated separately w/o communication. If both silent= both get 1yr, one confesses and other silent= 0yrs vs 5yrs, if both confess both get 3yrs.
What does Axelrod + Hamilton (1981) say is the best strategy for the prisoner dilemma?
Tit for tat strategy suggested that the best strategy for mutual benefit is staying silent but due to biological interactions, the assumption is that the same 2 individuals will meet more than once
What is altruism?
Behaviour at cost to oneself but benefit to others
How does altruism contrast to theories of evolution?
Contrasts to natural selection, survival of the fittest is not strongest but best at passing on genes.
What are the 3 aspects of kin selection in altruism?
Inclusive fitness
Hamilton’s rule
Price’s equation
What is inclusive fitness?
includes both direct fitness (offspring of an individual) and indirect fitness (offspring in same species)
What is Hamilton’s rule?
rB>C
R=genetic relatedness, B= benefit to recipient, C= cost to altruism fitness.
What is Price’s equation?
Mathematically explains how natural selection is connected to inclusive fitness as even if there is a cost to individual fitness, if net effect (genetic line) increases so does altruism
What are the 2 aspects of non-kin altruism
Reciprocal altruism
Group selection
What is Reciprocal altruism?
Benefits will be reciprocated in a similar situation, price equation= past cooperation predicts future fitness, iterated prisoner’s dilemma.
What is group selection?
More cooperation helps dominate selfish groups.
