Transcript Artificial Selection

Artificial
Selection
An introduction to evolution
Question?
 What

is artificial selection?
Where humans select organisms with
certain desired characteristics to breed
and produce the next generation.
 What
types of things do humans artificially
select for
Artificial Selection in Carrots
Inbreeding

The continued breeding of individuals with
similar characteristics.

Often seen in dogs

Helps ensure that the characteristics that
make breeds unique will be preserved

Not always a good thing: most members of a
breed are genetically similar so there is a
chance to pass down bad recessive alleles
Artificial selection gone wild
English bulldog
 Due to artificial selection for a very large head,
almost all need to be born via C-section
Artificial Selection in Cows
 We
are going to watch a few clips of
artificial selection in cows.
 In
your notebooks, write down the
questions for each clip so that you can
answer them as you watch. Biology is the
funniest class ever.
 http://www.pbs.org/wnet/nature/lessons/
the-perfect-cow/video-segments-holycow/1536/
Clip 1: A Cow’s Digestive
System
 What
role do microbes serve in a cow’s
rumen?
 Does
this clip illustrate naturally or
artificially selected attributes?
 Why
would a cow’s ability to eat grass
make it ideal for human domestication?
Clip 2: Desirable Breeding
Traits in Cattle
 How
many different breeds of cattle have
humans created?
 Would
the qualities that make good beef
cattle help them survive in the wild?
 Besides
milk and meat production, what
other traits might humans wish to breed in
cattle?
Clip 3: Different Breeds of
Cattle
 What
might indicate that a cattle breed is
adapted to cold climates like Scotland?
 What
to?
 Why
do the different breed names refer
might “adaptability” be a desirable
trait in a specific breed?