Download 3-3 ch4

 Warm-up: (9-27-16)
*ch.4-3 video notes and Biosphere 2 TED talk/rubric out for stamp!
 1. In convergent evolution, (analogous, homologous) structures are seen, while in divergent evolution,
(analogous, homologous) structures are seen.
 2. Explain how coevolution can be like an arms race between two species.
 3. T/F. Artificial selection selects the traits of one species and inserts it into the DNA of another species.
 4. How old is earth? How long has life been on earth?
 *copy hw from the board.
 Q/A
 Contrast fundamental and realized niche.
 Give an example of resource partitioning.
 What is an advantage of being a generalist?
 Specialist?
 What type of extinction is always occurs at a low rate?
 We are currently in the ___th mass extinction.
 What is the cause of this mass extinction?
 Take out your journal
 “Journal #4: Selection and Speciation”
 Number as you go.
 No complete sentences.
 Ch. 4-3
 Genetic Engineering
 Goals for today:
 Identify different types of selection
 Contrast the processes of genetically modifying organisms and artificial selection
 List pros/cons of GM crops
 Selection
 Four types:
 Stabilizing selection
 Directional selection
 Disruptive selection
 Sexual selection
 Stabilizing, disruptive, or directional selection?
 Ex. Lizards: big lizards are easily seen by predators, so they are eaten. Small lizards are too slow, so they are
eaten. The average sized lizards are selected for.
 Ex. Anteaters with long tongues can prey on termites better than those with short or average length tongues. If
an area has termites with very deep nests, the longer tongues would be selected.
 Stabilizing, disruptive, or directional selection?
 Ex. Limpets: dark shell color limpets that live on dark colored rocks are hard for birds to see. Light shell color
limpets are on rocks with goose barnacles that are also light colored. Again, hard for birds to see. The
intermediate colored shells are easy to see on dark or light backgrounds.
 Contrast stabilizing and directional selection.
 #4 on Finch Article
 GENETIC ENGINEERING AND THE FUTURE OF EVOLUTION
 We have used artificial selection to change the genetic characteristics of populations with similar genes through
selective breeding.
 Genetic Engineering:
Genetically Modified Organisms (GMO)
 Contrast transgenic organism and recombinant DNA.
 The host organism receiving the recombinant DNA is called a transgenic organism.
 Some GM foods/crops…
 Salmon
 Milk



















Soy
Corn
Potatoes
Rice
Papaya
Tomatoes
Cotton
rBGH (recombinant bovine growth hormone): growth hormone made by bacteria that makes cows produce
more milk
Some possible cons to GM crops…
Decreased genetic variety in GM crops
Can affect native plant diversity with spread of new genes
Impact human health???
Could impact health of ecosystems
Requires use of more pesticides (sometimes)
Over use of pesticides could lead to…
Check for Understanding:
1. How is foreign DNA inserted into a plant cell?
2. What have animals/crops been genetically engineered to do?
3. A medium sized insect is favored in this type of selection.