Transcript The Best Genes for the Job!

The Best Genes for the Job!
Kate and Michael
How did you get to be the way you
are today?
Think about why you are the height you are…or
why your favorite foods are your favorite
How did you get to be the way you
are today?
Genes
Images: wikimedia.org, healthparley.com
+ Environment
Nature vs. Nurture
• Q: What is more important in determining your
physical and behavioral traits, nature (genes) or
nurture (environment)?
Nature vs. Nurture
• A: Both
• Genes and the environment both play an
important role and often interact with each
other
Images: neihs.nih.gov
Genotype-Environment Interaction
(GxE)
• A GxE is when genes and the environment interact with
each other to determine how a trait is expressed
• The same genes in
different environments
may not result in the
same phenotype
Images: gatech.edu
Maze-Running Ability in Rats
• Two different genotypes were created “bright” and “dull”
• “Bright” rats do better at running a maze than “dull” rats
• BUT…this difference in ability disappears if the rats are
raised in a more social environment with lots of objects
to explore
• The bright genes only outperform the dull genes in
certain environments
Cooper and Zubek 1958
Plant Height and Altitude
• Seven different yarrow plant genotypes were all grown at
low, medium, and high elevations
• No single genotype grew the best at all elevations.
• Altitude influenced plant height, but not in the same way
for all genotypes
Clausen et al. 1948
Sickle cell anemia
• Autosomal recessive disease
• Carriers have symptoms when deprived of
oxygen or dehydrated
Images: wikimedia.org, abbotlab.wordpress.com
Sickle cell anemia
• Adaptive advantage: the heterozygote (carrier)
is resistant to malaria
• Carriers still have some defective hemoglobin,
which the parasite cannot digest
• SCA persists in areas where malaria is present:
historical distribution of Malaria
Images: wikimedia.org
distribution of the sickle-cell trait
MAOA and Antisocial behavior
• The amount of MAOA
enzymes can influence
violence and antisocial
behavior in humans
• Low levels of MAOA
increases the risk of
antisocial behavior in
adults…BUT…only when
they were raised in an
abusive environment
Caspi et al. 2002
The best genes for the job!
• You are all birds. There are two different
genotypes for beak shape (spoons and
tweezers)
Images: igourment.com, photohome.com, neillosin.com, webstaurantstore.com,
The best genes for the job!
• Your goal is to “eat” as much as possible by
picking up beans with your beak
• There are two different environments to feed in
Images: webstaurantstore.com, igourmet.com, foodsubs.com
The best genes for the job!
• Which genotype is best?
Images: powernet.co.uk, 9bar-espresso.com, happyfolding.com
An additional experiment
Big bluestem
Images: podepauw.edu, nps.gov
Little bluestem
An additional experiment
Big bluestem
• Can reach 10 ft. in height
• Prefers deep fertile soil
LaGory et al. 1982, wildflower.org
Little bluestem
• Usually ~3 ft. in height
• Do well in gravel, sandy soil