basic about altrisum

1. ALTRISUM
By:-Varta
Tsering

2. • The word altruism, which come from the
Italian altrui .(Benevolence)
• Coined in 1851 – August Comte
• Edward O.Wilson “ Self –destruction behavior
performed for the benefit of other.”

3. • Altruism: Helpful behaviour that lowers the
helper’s reproductive success while increasing
the reproductive success of the individual being
helped.ie where an animal does something that
is costly to itself but benefits another.
• Common altruistic behaviour –
Mutual grooming, the giving of alarm call to
warn conspecifics ,food sharing ,group defence.

4. Food Sharing
Alarm call to warn
conspecifics

5. Source :Internet
Mutual Grooming

6. Example
• Amongst the social insects, most individuals in the colonies of
termites and wasp ,bee and ants are sterile female worker, who
never reproduce themselves, but devote their lives to defending
feeding,caring for their young sibling .
• Belding’s Ground Squirrels give piercing alarm calls when a predator
is spotted.
• In numerous bird species, a breeding pair receives support in
raising its young from other “helper birds” ,including help with the
feeding and protecting the nest.
• African buffalo will rescues a member of the herd captured by
predator.

7. Hamilton's rule
kin selection causes genes to increase in frequency
when the genetic relatedness of a recipient to an
actor multiplied by the benefit to the recipient is
greater than the reproductive cost to the actor.
r= the genetic relatedness of the recipient to the actor
B= the additional reproductive benefit gained by the recipient of
the altruistic act
C= the reproductive cost to the individual performing the act.

8. example
• The Naked mole rat .(dry desert in Southern
Africa)
• They are almost hair less .Their burrow systems
can be extremely extensive up to 3.5 km and by
70 to more than 200 individuals.
• Their is just one breeding female and up to three
reproductive males.
• The reproductive female produces up to 27 pups,
giving the sterile workers lots of closely related
young to look after.

9. fig :Naked mole rats live
underground in colonies
of closely related
individual

10. • The florida scrub jays
• Which also have sibling helper, the majority of
helpers are male and the sons of the birds they
help.
• Benefit: that they tends to take over part or all of
their parent’s territory in future,when they
themselves start to breed.
• Cost of helping: that of postponing reproduction
for a year and appears to be shortage of nest
sites , making it very difficult for young birds to
breed at all.