Transcript Natural Selection

evolution
How it relates to the study of
behavior and experience
Natural
selection
 Species have changed, by adapting to
their ever changing environments,
through a process known as natural
selection.
 It has three components.
 1) Individual animals compete for limited
resources so that they can reproduce
and ensure that their children (and the
genes they carry) will have an
opportunity to live and reproduce.
 2) Individual animals differ from each
other because of their unique genetic
heritage, usually through crossing over
and occasionally through genetic
mutation – random errors in gene
replication.
 3) If these differences give individual
animals an advantage in reproducing
and raising their young, they will become
more and more common in succeeding
generations.
 Darwin called this process anagenesis
the transformation of a species.
More simply,
 It’s hard to raise young.
 Some traits/abilities help.
 If they do, they will be more and more
common in future generations.
Recent evidence of
human evolution
 In September of 2005 new evidence
emerged concerning two particular
genes’ role in brain size
 The findings suggest that these genes
have changed within the last 6,000 years
and may continue to do so today
 Greg Wray, director of Duke’s Center for
Evolutionary Genomics, “… it’s almost
impossible for evolution to not happen.”
Applications for
human behavior
 Some psychologists argue that certain
behavioral tendencies and thinking and
learning capacities helped humans raise
more young and send more of their
genes into the future.
Darwin’s
prediction
 While mainly concerned with biology,
Darwin prophesized, in 1859, natural
selection’s future influence on
psychology.
 It would, “… open fields for far more
important researches. Psychology will be
based on a new foundation.”
applications
 Why do men strive so hard for status,
dominance, and $$$?
 Because that is what women look for in a
mate.
 Why do women care so much about
looking young and healthy?
 Because those are the traits men select
in picking a wife.
more
 Why are men more likely to play around?
 Or are they?
 Why do some animals, even humans,
sacrifice their own reproductive
prospects to help raise their siblings or
even nieces and nephews?
Other points
 Evolution is a battle fought by individuals
not by species.
 It’s not really, “The survival of the fittest.”
 More accurately, it is, “You must breed
to succeed.”
Back to Charles
 “Today, in 2006, the ideas of Karl Marx
are dead, Sigmund Freud’s are on life
support, but Charles Darwin's grow
stronger every day.”