1. Evolution and Environmental Science

4. Natural selection Natural variability in the population
Variability in resistance to pesticides
Some individuals highly susceptible
Some individuals highly resistant
Characteristics of individuals are heritable (passed on from generation to generation)
Pesticide application to crop kills the susceptible individuals but not the resistant ones

8. Resistant Individuals

9. The Result
By natural selection the population has evolved resistance to the pesticide
Spend millions to develop a new pesticide
Repeat the process
A continuing evolutionary arms race with pest organisms

10. Can this pattern be broken?
Evolved resistance
Develop new pesticide
Can this pattern be broken?

11. Genetic Engineering and the Environment
Cloning
A bad idea for industrial agriculture
No variability in the flock on which natural selection can work
All susceptible to the same pests, diseases or predators
What are the reasons for cloning?
Organ banks

14. Genetic Engineering of Crops
Insertion of beneficial genes
Bacillus thuriengensis or Bt
Insert the Bt gene into corn
All cells of the corn plant produce the Bt toxin killing pests that eat the corn
That is good……
But…….

15. Evolved resistance
to Bt
Develop new
gene

16. Transfer of pollen
to non target species

17. Transfer of pollen
to non target species

18. Evolotion of a superweed
Transfer of pollen
to non target species

20. Other transgenic organisms