Social Learning Problem Set
Imagine the following evolutionary scenario. In an intelligent
primate species, it takes an infant almost a year to mature sufficiently
to be able to take care of itself. During that time, it is constantly
cared for by its mother. The infant learns by imitating its mother
and only its mother during that first year of life. After that
year, the young offspring will not learn any other behaviors through
imitation. Consequently, the infant must learn what foods to eat,
what foods to avoid, what animals are dangerous etc. during this
As a consequence of this learning mechanism, there is a high correlation
between mother and offspring for many different behavior patterns.
For example, some mothers transmit the ability to ÏfishÓ
for termites and ants using sticks while mothers who were not
taught this during their sensitive period cannot transmit this
A mutation occurs in a gene that effects the sensitive period.
The mutation extends the sensitive period well into adulthood.
As a result, the individual is able to imitate other adults and
other youngsters in the troop after its first year of life.
In two pages, give a plausible evolutionary scenario for what
might happen with this this new mutation. Make certain that you
address the following points in your write up:
- 1. Would this mutation be advantageous or disadvantageous?
- 2. Would the frequency of the new allele increase over time?
- 3. A major staple in the diets of these primates is the coconut.
Individuals learn how to break the outer shell by imitatation.
For two years, a blight occurs and the coconuts rot before they
mature. Would this mutation increase in frequency during this
time when many members of the troop are severely malnurished?
- 4. Currently, the primate species inhabits the tropical savannah.
How would this mutation influence the ability of this species
to colonize a new ecological niche such as a desert or a tropical
- 5. If this mutation were to increase in frequency, what would
happen to the mother-offspring correlation?
- 6. The males of this species have a strong dominance hierarchy
which is maintained by combinations of posturing, intimidation,
and displays. How might this mutation influence a young maleÌs
chance of increasing his order in the hierarchy?
- 7. In a similar way, how might this mutation influence the
ability of a mother to care for her offspring?
- 8. Suppose that a primatologist gathered data on "fishing"
for termites. Those primates who actually fished for the termites
are given the value 1 and those who do not fish for primates are
given the value 0. The primatologist gathered data on the female
primates and their first born offspring before the mutation occurred
and then 20 years after the mutation occurred. What would be the
correlation between maternal fishing and offspring fishing before
the mutation and what would be the correlation after 20 years?
(You do not have to give a number--just say "high,"
"medium," "low," etc.)