Bio3520
Chapter 8
Kinship
Many colonial
animals
exhibit
(altruistic) behavior, such as giving
alarm
calls, as a consequence of
selection.
Kinship also plays a role in preventing
behavior.
Kin selection can be explained by
fitness:
an individual can proliferate its
by producing its own offspring, or offspring of close relatives.
The selective advantage of altruism can be quantified by measuring:
the
to the recipient (
b
)
the
to the altruist (
c
)
the
of
relatedness
(
r
)
Natural selection favors altruism when
rb > c
(
rule); this can be estimated by counting
offspring.
fitness can be a model for understanding behaviors associated with family dynamics.
breeding
is
correlated
with genetic
relatedness.
Family
can occur when reproductive opportunities materialize
elsewhere.
Families that control high-quality resources may become
in which the resource is
transmitted,
sometimes by
territory
, over successive generations.
Step-parents invest
less
in their stepchildren than in their
children.
Parent-offspring
conflict
can also occur, as in weaning
situations.
rivalry
can be
intense,
especially when
are
scarce;
a major factor in sib-sib
competition
is
order.
Kin
may be
based
on an "internal template" using visual or chemical cues.
Some species simply accept individuals in their
as kin, though this strategy can be
broken
by
parasites such as cuckoos.