Download Artificial Selection

Artificial
Selection
By: Krista Coleman and Justin
DeCotiis
Starting Question
Is it possible for you to use natural
selection on an organism of your
choice? Why or why not?
The objective is to be able to answer
these questions:
•
•
•
How does artificial selection
compare and contrast to natural
selection?
How do people produce
offspring with preferred
characteristics?
What does evolution act upon
within a population?
Adaptive Radiation: What is it?
•A common ancestry
•Association between
environments and the
traits used to exploit
those environments
•Rapid speciation:
presence of one or
more bursts in the
emergence of new
species
Misconception: “Evolution
is a theory about the origin
of life.”
Evolutionary
theory deals
mainly with
how life
changed
after its
origin.
Misconception: “Evolution is like a climb
up a ladder of progress; organisms are
always getting better.”
Natural
selection
weeds out
those unfit.
No organism
has to be
perfect.
Misconception: “Evolution
means that life changed ‘by
chance.’ ”
Chance is certainly a factor in evolution,
but there are also non-random
evolutionary mechanisms. Random
mutation is the ultimate source of genetic
variation, however natural selection, the
process by which some variants survive
and others do not, is not random.
Natural Selection Review
•
Variation in traits
•
Differential reproduction
•
Heredity
•
The more advantageous trait which allows the
organism to have more offspring becomes more
common in the population
Your thoughts: What is artificial
selection?
Initial Model
•
Draw and describe your ideas on how
modern corn came to be on your
worksheet
Artificial Selection
•
•
•
Researchers start with phenotype
(rows of kernels per ear, number
of ears per plant)
Then, look for associations
between particular traits and
particular sequences in the
genome
Target the gene for selection and
breed for the beneficial trait
(more kernels, more ears)
How is the evolution of corn
related to natural selection?
Different
Same
Wild to modernhow do we get there?
Wild sunflowers (left) and
domestic sunflowers (right)
Wild tomatoes (left) and
domestic tomatoes (right)
Teosinte plant (left) and
corn plants (right)
Bottleneck
What is this saying about genes in domestic
crops versus their wild counterparts?
Why do we care about
artificial selection?
• Answer the questions about
farming with a friend
Is artificial selection good?
• Examine the article about foxes
Are humans being artificially
selected? How or how not?
• Support your ideas and present
your hypothesis with a partner or
two