the evolution of kin selection
TRANSCRIPT
THE EVOLUTION OF KIN SELECTION
By Aditya KuroodiPeriod 5
Key Vocab Fitness of an Animal: How many offspring
it has, which leads to number of genes present
Individual Fitness: Number of own offspring and genes passed on
Inclusive Fitness: Ind. Fit. + Number of identical offspring and genes passed on
Altruism: Selfless concern for the welfare of others
Kin Selection Kin selection is a theory
about the evolution(persistence) of altruism
When animal risks itself to help relatives survive
Since they’re related, some of that animal’s genes still get passed on
Altruistic animals still persist because their genes are present in the relatives they save
Kin Selection Natural selection technically
shouldn’t allow for evolution of altruistic animals
But kin selection theory proved that it could
Kin selection says that relatives also might contain the “altruistic gene”
Thus, offspring still receive gene, and altruism continues
Altruism is preferred on a group basis, not an individual one, unless it has to do with kin
Fire Ants All ants are Euosocial Have sterile workers and
Queen to reproduce Because they are
haplodiploid Normally, no one would be
sterile Sisters share 75% genes w/
each other More effective to help
Queen make sisters than have own offspring
This is kin selection at its finest
Alarm Calls in Squirrels Many squirrels have alarm
calls when they sense danger
The squirrel that makes the call puts itself in risk, but saves others around it
The closest animals around it are most probably kin
The kin survive, and the ability to make an alarm call persists
Also, scientists have discovered that some squirrels change the call if relatives aren’t around
Cool Squirrels
Cool Squirrels
Scientists The idea of kin selection
was pondered at first by Darwin
“a tribe including many members who...were always ready to give aid to each other and sacrifice themselves for the common good, would be victorious over most other tribes; and this would be natural selection” (p.166)
Darwin thought altruism was caused by group selection
Evidence against Group Selection
The idea of group selection was quickly discarded
Idea of “free riders” cashing in on groups of altruists (Dawkins)
They would have huge advantage and take over; altruism would be run over by selfishness
This was from works of John Maynard Smith, Richard Dawkins, W.D. Hamilton and G.C. Williams
W.D. Hamilton Main man in the world of kin
selection Used inclusive fitness to
support theory Inspired by Haldane, and
R.A. Fisher His rule RB>C explains when
altruism would continue R is how related the animals
is (brother vs cousin, etc) B is benefit to
group(Inclusive fitness) C is cost to individual ( Loss
of Individual Fitness)
Contribution of Kin Selection Theory
Kin selection puts a new spin on the classic ideas of natural selection Darwin imposed
It differs from the view that evolution and life is on a strict individual basis
Relationships in animals plays a major role in evolution
There could be an “Altruistic Gene” that is passed on or not
Timeline
Works Cited http://plato.stanford.edu/entries/altruism-
biological/
http://taumoda.com/web/PD/library/kin.html
http://es.rice.edu/projects/Bios321/eusocial.insect.html
http://www.animalbehavioronline.com/haplodiploidy.html
www.Wikipedia.com