inclusive fitness essay content Flashcards
hamiltons rule
rb<c
r = relatedness
b = benefit
c = cost
parent child: r = 0.5 so benefit to receiver would have to be two times the cost to the benefactor in order for an allele for helping kin to be selected for.
Intro content
Inclusive fitness introduced by Hamilton in 1960’s revolutionised our understanding of cooperative behaviours IN EVOLUTIONARY BIOLOGY.
This essay delves into the meaning of inclusive fitness and ASSESSES ITS CONTRIBUTIONS TO ELUCIDATING THE MECHANISMS DRIVING COOPERATIVE BEHAVIOURS.
Through CRITICAL EVALUATION and empirical evidence, this essay explores the extent to which inclusive fitness has advanced our COMPREHENSION of cooperative behaviours.
what is inclusive fitness?
introduced by Hamilton in the 1960’s
Encompasses both direct and indirect fitness (Direct = measure of number of surviving offspring, indirect = measure of number of surviving relatives)
Organisms can increase their overall genetic representation in future generations by helping relatives who share copies of genes.
KEY WAYS in which it has aided our understanding of cooperation is by providing a framework to explain why individuals might engage in seemingly altruistic acts.
Kin selection theory
inclusive fitness provides a theoretical underpinning for the kin selection theory, even though the two theories are very similar.
Individuals can increase their inclusive fitness by helping relatives (particularly close to kin who share genetic material)
This theory explains the evolution of altruistic behaviours observed in social organisms such as cooperative breeding in birds.
Parents invest in offspring cos for any given offspring there is a 50% chance it will also have an allele to help offspring.
reciprocal altruism
inclusive fitness informs our understanding of reciprocal altruism, whereby individuals engage in cooperative behaviours with unrelated individuals, Possibly expected future benefits
BY QUANTIFYING THE INCLUSIVE FITNESS EFFECTS OF RECIPROCITY, RESEARCHERS CAN MODEL THE CONDITIONS UNDER WHICH COOPERATIVE STRATEGIES CAN EVOLVE AND PERSIST IN POPULATIONS, EVEN IN ABSENCE OF KIN.
Critical analysis point 1
IT IS ESSENTIAL TO CRITICALLY EVALUATE THE CONCEPT OF INCLUSIVE FITNESS.
it provides a useful framework for understanding cooperative behaviours, it has also been criticised for its limitations.
One criticism is that it may oversimplify the complexities of social behaviour by focusing solely on genetic relatedness and neglecting other factors that influence cooperation, such as reciprocity and individual differences.
BIRCH AND OKASHA, 2015.
OVERSIMPLIFIES COMPLEXITIES OF SOCIAL BEHAVIOUR.
Critical analysis point 2
recent advancements in evolutionary theory such as MULTILEVEL SELECTION (WILSON 1997) ANDDD cooperation through social norms offer an alternative framework for understanding cooperation that go beyond inclusive fitness.
THESE frameworks emphasise the role of group level selection, cultural evolution and psychological mechanism in shaping cooperative behaviour. CHALLENGING THE EXCLUSIVE FOCUS ON GENETIC RELATEDNESS IN INCLUSIVE FITNESS THEORY.
final critical analysis point
FOSTER ET AL., 2006 provides evidence for inclusive fitness remaining the key explanation for altruistic and cooperative and cooperation behaviours.
conclusion
inclusive fitness significantly advanced understanding of cooperative behaviour by highlighting the importance of genetic relatedness in shaping social interactions.
further research needed using a possible mix of different mechanisms to explore the interplay between between genetic relatedness, reciprocity and cultural factors.
references
Hamilton 1960’s
Birch & Okasha, 2015 - inclusive fitness oversimplifies complexities of social behaviour.
Qui et al., 2023 - found that shared negative experiences facilitated cooperative behaviours - hinting that there is more to cooperative behaviours.
Wilson, 1997 - multilevel selection
Foster et al., 2006 - inclusive fitness remains key explanation
