Lecture 2 - inclusive fitness theory and practice

Question 1

who was the first person to tackle the paradox of cooperation?

Answer 1

darwin 1859 - he was aware of mutualisms and believed there must be a selfish element of any structure
he became very close to what is now known as kin selection theory

Question 2

what became the issue in understanding cooperation in the 19th century?

Answer 2

Became very focused on competition and little emphasis was put on cooperation culminating in social darwinism and eugenics (francis galton)

Question 3

what was peter kroptokins view?

Answer 3

started to put more emphasis on cooperation instead of competition however he … used philosophical and social argument and provided no evolutionary mechanisms

Question 4

the dark ages of evolution were thought of as before what synthesis came about?

Answer 4

neo-Darwinian modern synthesis that brought together natural selection, Mendelian genetics and population genetics in 1930s-1940s

Question 5

who were the two founds of the neo-darwinian modern synthesis?

Answer 5

• RA Fisher (1890-1962)

- JBS Haldane (1892-1964)

Question 6

what idea did the neo-darwinian modern synthesis establish?

Answer 6

Traits favored by natural selection are those that enhance individual fitness - this was established mainly by fisher he also considered that there can be indirect effects in which an animal favors or impedes the survival or reproduction of its relatives

Question 7

what did haldane start to come up with?

Answer 7

started to come up with the idea now know as inclusive fitness where the level of relatedness effects how you act - Q. Would he lay down his life for his brother?
-A. “two brothers or eight cousins”

Question 8

what did hamilton come up with?

Answer 8

Saw social interactions everywhere, and potential for an evolutionary theory of altruism= inclusive fitness theory

Question 9

describe the inclusive fitness theory

Answer 9

shifting the focus from the individual and down to the area of the gene – i.e. genes for altruism spreading throughout the population
- your fitness is not only to do with your offspring but also the offspring of any of your relatives

Question 10

inclusive fitness theory states that a gene can increase transmission to the next generation by increasing fitness of?

Answer 10

1) direct fitness - individual it is in

2) indirect fitness - individuals with copies of that gene (kin selected fitness)

Question 11

what is it called when you combine direct and indirect fitness?

Answer 11

inclusive fitness

Question 12

how does hamiltons view differ from fishers?

Answer 12

hamilton talks of inclusive fitness vs fisher talks of ONLY personal(individual) fitness (direct - no help from actor to recipient)

Question 13

what can personal fitness also be known as?

Answer 13

neighbour-modulated fitness

Question 14

what are the 4 outcomes in hamiltons table of social interactions?

Answer 14

1) mutually beneficial
2) altruistic
3) selfish
4) spiteful

Question 15

what is the official definition of cooperative behaviour?

Answer 15

Cooperative behaviour benefits another individual and has been selected for, at least in part, because of its beneficial effects on the recipient

Question 16

which two social interactions are examples of cooperative behaviour?

Answer 16

1) mutually beneficial

2) altruistic

Question 17

what can inclusive fitness be applied too?

Answer 17

Inclusive fitness is very general, it can be applied to actions whose effects on recipients are negative rather than positive

Question 18

what is the problem of measuring fitness?

Answer 18

In practice, measuring inclusive fitness may be hard to measure – you need to know relatedness and the reproduction of the actor and recipient etc

Question 19

what is hamiltons rule used for?

Answer 19

used to understand whether a social trait is adaptive or not

Question 20

what is hamiltons rule?

Answer 20

altruisms evolves if rb>c or rb-c>0
r= relatedness between actor and recipient
b= fitness benefit to the recipient
c= fitness cost to the actor

Question 21

describe the example of kin selection in turkeys?

Answer 21

turkeys Males form coalitions to court females
- dominant gets all matings – the males in the coalitions are closely related – benefit to dominant male have a subordinate male by his side – can work out costs and benefits by using Hamiltons rule – solitary males are very unsuccessful so the cost is small and therefore outweighed by kin-selected benefit

Question 22

estimating fitness is challenging, what are solutions to the problem of measuring fitness?

Answer 22

• Productivity of offspring, not adults, in lifetime
• Snapshot of productivity (some have long lifespans)
• single season or reproductive attempt
• offspring condition
• mating success (assume mating success is correlated with fitness)
• Survival across a discrete time interval
• Energy budget, food intake, etc…

Question 23

what behavioural phenomena has inclusive fitness helped us understand?

Answer 23

1) sex allocation
2) selfish genetic elements
3) parasite virulence
4) conflict resolution
5) spite
6) evolution of sociality

Question 24

what are two important point to consider regarding inclusive fitness theory?

Answer 24

1) inclusive fitness is entirely general in that it applies to negative aswell as positive interactions among individuals
2) the logic is deceptively easy but the practicalities of measuring direct and indirect components of inclusive fitness are challenging

Question 25

what are major evolutionary transitions regarding the evolution of life on earth?

Answer 25

• origin of chromosomes
• origin of eukaryotes
• origin of sex
• origin of multicellularity
• origin of social groups
• origin of human society/language

Question 26

what does each evolutionary transition involve?

Answer 26

cooperation

- so social evolution theory explains each transition using the logic of inclusive fitness theory

Question 27

what was the hypothesis for the origin of mutlicellularity - Why should single cells join to become mutually dependent? ?

Answer 27

High relatedness between cells played key role in transition to multicellularity

Question 28

describe ratcliff 2012 study investigating the role of relatedness in the transition to multicellularity

Answer 28

Selected for multicellularity in unicellular yeast
found multicellular traits:
- deferred reproduction
- division of labour (apoptosis)
- over 60 selection intervals they scooped away the top of the yeast and left any yeast cells clustered at the bottom of the culture – gravity was the selective agent for multicellularity/aggregation – at the end they looked for multicellular traits
- Multicellular clusters form by clonal adhesion – high relatedness
- If it was aggregation you would expect low relatedness
- This model shows that high r is important for the multicellular traits

Question 29

what was fishers approach in understanding the origin or multicellularity?

Answer 29

comparative analysis (Fisher et al 2013) – Compare multicellular form in clonal (r = 1) and non-clonal (r < 1) taxa

Question 30

what is the cooperative transition from unicellular organisms to mutlicellular organisms influenced by?

Answer 30

relatedness - determined by the process of group formation