Entropy Pump
our human bodies won't ever change temp w/ the room we are made of pumps
2 word summary of evolutionary psychology
Thats weird
One sentence summary of evolutionary psychology`
The brain is a physical system
designedly natural selection
composed of many functionally specialized circuits
formed over the course of our species evolutionary history
that largely operates outside of our awareness
Actions=
world-->sensory system-->brain-->muscle behavior
brain transducer info from states of the world through energy
and senses
obeys laws of physics at every step
2 features of adaptive problems
1. reoccured over course of species history
2. solution to problem affected reproduction (indirectly)
Tinbergens 4 questions
1. causation- neural, hormonal, physiological, cellular that give
rise to behavior
2. Ontogeny: How the behavior arises during the process of development
3. Function: The Role that the Behavior Plays in the Organism
Adaptation to its Environment
4. Phylogeny: How continuous with and different from other
species- including extinct species from which it might have descended
Evolutionary Psychology
approach to ALL psychology
search for minds competencies not its limitations
Blindness to Structure
Second Law of Thermodynamics
Entropy
universe moving to state of disorder
energy lost as heat
Baby and mothers milk
Voice of mother, Human faces, Locate sight, sound, smell
"prefeeding responses"
55 mother-infant pairs (73 hours old) babies were in calm state
scentless breast
odorous breast (breast group, nipple group, areola group, milk group)
cried more during scentless, eye opening was longer in any
odorous, oral activity higher in odorous
6 views of natural selection
1. Analogy with Gravity
2. Organism Design
3. Analogy with Engineering
4. Axiom (uses logic & deduction, needs no evidence)\
5. Replicators vs. Vehicles
6. What do genes do
4 fundamental gravity interactions
Strong force- binds the nucleus, keeps from blowing it up, keeps
protons together, very strong at very small range
Electromagnetic force- bings atoms
Weak force- still stronger than gravity over small distances
Gravity - binds the solar system, weak over large distances
4 forces of evolution
1. Gene flow (Immigration, between 2 populations)
2. Genetic Drift (disasters or founder effect)
3. Mutation- in sex cells (mostly neutral, some deleterious,
rarely beneificial)
4. Natural selection (evolutions gravity, powerful under long
scales of time)
William Paley
Natural Theology
Nature is evidence for god
Watches imply the existence of a watchmaker
Eyes imply the existence of an eye maker
Problem of Paley
infinite regress
explains simple things with more complex things
Solution: explain complex things through simple things
Thomas Malthus
how big should taxes be to take care of poor
An Essay on the Principle of Population
more food=more babies, famines are inevitable
causes die off... survivors have low body temp, strong immune,
metabolism that can handle hunger
Alfred Russel Wallace
Wrote theory of natural selection before Darwin
The Linnean Society publishes both essays back to back
The Origin of Species
Organisms produce many more offspring than are required to replace
the parents
Population shows a range of variability across physiological and
behavioral traits
Some traits better favor reproduction and survival than others
Traits of successful parents will be better represented in the
next generation. If features of environment remain same over
generations, population change will become directional
Enough change may accrue to reproductively isolate a population
making them a new species
Why natural selection isn't like engineering
not forward looking
no goals
design can't tear down existing design
many prototypes
low planning-to-tinkering ratio
3 ingredients of natural selection
Replication: make copies of themselves
Variation: some copies are not exact replicas
Differential Survival: some survive and reproduce better than
others (selective retention)
Natural Selection : Replicators
Some replicate faster than others
Copying errors (1. cause replicator to decrease its replication
rate, 2. cause replicator to increase its replication rate or don't
change it)
Replicators and Vehicles
DNA= replicator
Cells= vehicle replicators live in
genes live forever by making copies and humans are the vehicles
Four steps for protein synthesis
1. DNA within the nucleus is partially unraveled
2. Ones genes RNA is transcribed and moves out of the nucleus into
the cytoplasm
3. mRNA strand attaches to a ribosome and creates an amino acid
thats added to protein
4. A codon at the end of mRNA tells ribosome to stop and let go of protein
Mutation
Permanent change in DNA structure
spontaneous... or induced (x-rays, too much sun)
if mutation happens in somatic cell then it will spread locally in
the body from cell division (white hair patches)
if in reproductive cell, mutation is heritable
Point mutations
single base-pair change
Silent- no change in amino acid
Missense- different amino acid coded
Nonsense- insertion ofa stop codon. stops it prematurely
Frameshift- insertion or deletion of nucleotides. produce LARGE changes
most lead to reduced function
Large Scale Mutations
Deletion of large chromosomal regions
Inversion- Reversal of orientation of a segment
Insertion: add one or more nucleotide into the DNA
Translocation: interchange of genetic parts from non homologous chromosomes
Duplication: creates copies of chromosomal regions
Amalayse gene
we have duplications that metabolize carbs
we have much more than chimps
Fitness
Causes survival, not the other way around
On population level not individual level
Absolute Fitness
(#of individuals with genotype after selection)/ (# of individuals
with genotype before)
>1.0 = increased frequency
<1.0= Decreased frequency
Inclusive Fitness Theory
only major revision since Darwin
inclusive fitness= direct fitness+ indirect fitness
ex. sterile worker bees
maximization of inclusive fitness is the purpose of natural selection
Indirect Fitness
Hamiltons Insight on Inclusive Fitness Theory
behaviors that boost reproductive success of related individuals
Family relatedness
.5- parents and siblings
1- identical twin
Relatedness
probability that random gene selected from I is identical by descent
with one present in J
r=
proportion of one individuals genes that are identical by direct
descent with those present in another
AKA kin selection theory
Relatedness of A & B with gene G
p(G|A) - p(G)
--------------
p (G|B) - p(G)
Bees
Male bees don't have fathers
clones of queens
males only have one chromosome
r between bee sisters= .75
r between brothers and sisters = .25
stabilizing selection
remove extremes and reduces variation
Directional selection
favors one extreme
mean value moves
Disruptive (diversifying) selection
Favors extremes
Adaptation
drives species to sameness
promote inclusive fitness
not all traits are adaptations, some are byproducts
Does not happen for the good of the species but to help with
individuals success
Evaluating if something is an adaptation
1. Can you find a cause/selection pressure
2. Is it still doing its job correctly
Appendix
No other primates have appendix
If it was vestigial our most recent common ancestor would have it
Hunters/ Gatherers don't die from appendicitis, only modern world
Presence of indoor toilet is risk for appendicitis
after diarrhea, no bacteria in gut
appendix doesn't flush out it redistributes bacteria
with hygiene you don't need it as much, it becomes sick from non use
Opposite of sex
Asexual
clone is produced
early organisms produced asexually by parthenogenesis (Virgin birth)
Aphids asexual in summer and sexual in winter
Cost of meiosis
Only half of genes are in offspring
Cost of recombination
Break up winning design
Cost of mating
Search costs, attracting a mate
Mullers Ratchet
Asexual Reproduction pasts on all mutations
good designs are disrupted by deleterious alleles
Pathogen Theory of Sex (red queen theory)
We have sex to stay ahead of pathogenIcorganisms that are always
evolving inside us
cancer
parasites reproduce every 15 minutes
its always trying to adapt to destroy us (asexual- already adapted
to exploit the clone, sexual- parasites have to readapt)
Polymorphism
2 or more alleles at single locus
adds variability to sex
Anisogamy
different sized gametes
minimize genetic conflict
Disruptive selection
sperm has less genetic material
less fighting with egg
Eggs
female supplies the cytoplasmic genes
male do not
a sperm (cheater) better fit for selection because it gives all
their genetic material but doesn't take much energy
large gametes, small #'s, costly
Runaway selection (diversifying)
between sperms and eggs, sperm selected for smaller investments
eggs selected for larger investments
sperm has small gametes, large #'s and energetically cheap
Meiotic recombination
Genes get shuffled
reason were not all male
Evolutionary Stable Strategy
having 50/50 men and women
stabilizing selectin
Trivers
Parental investment- increases offsprings chance of survival at cost
of parents ability to invest in other offspring
Females
reproduce slower than males
scarce resource for males
reproduction limited by food and condition
male reproduction limited by females
Profession and mating
Hunter Gatherers- little heritable wealth (no advantage)
Herding and gardening- heritable wealth (advantages)
Farmers- dependence on land, huge amounts of resource inequality
farmers have more wives
Direct male parental investment
feeding, protection
Indirect male parental investment
provide and defend territory
Factors that influence male care
1. External v internal fertilizaiton
2. Effective care by 1 or 2 parents
3. can deserting improve his reproduction
4. Paternity certainty
Monogamy
1 male 1 female
Polygamy
more than 1 partner
Polygyny
male with more females
Polyandry
female with more men
Promiscuity
both male and female with more partners