LECTURE 12: APPLIED EVOLUTION

Question 1

What are examples of Applied Evolution

Answer 1

1. Agricultural resistance - resistance to herbicides and pesticides
2. Evolutionary medicine - resistance to antibiotics and evolutionary proof medicine
3. Global change and climate change - adapt or go extinct

Question 2

Pest Evolution: The problem

Answer 2

• Pests are controlled by the use of resistant chemicals.
• ## Plants quickly develop resistance to the chemicals that we impose them

Question 3

Weeds and Agriculture: The Major Problem

Answer 3

Weeds account for 34% loss of crop growth. This corresponds to 26 billion dollars of loss in the American economy per year

Question 4

Where does resistance in weeds come from?

Answer 4

1. Pre-existing genetic variation that gets “awoken” when the crop is exposed to chemicals
2. New genetic variation that imposed by the selection pressures that come with addition of chemicals
3. Gene flow between populations corresponds to high levels of resistance (we see that outcrossing plants have more variation for resistance than selfers - JULIA Kreiner)

Question 5

The evolution of resistance in waterhemp

Answer 5

We see that the variation of resistance of water hemp in Southern Ontario is very similar to the resistance of waterhemp in the midwest which can be associated with long-distance dispersal

Question 6

Ways in which resistance can be stopped

Answer 6

1. Using a variety of chemicals at once - will reduce the amount of new genetic variation imposed due to the fact that using many different chemicals would cause for a greater adaptation for resistance and thus this would not happen quickly
2. Cycling chemicals to alternate the selective pressures o the individual so they do not have the ability to evolve resistance to one or will not have the opportunity to

Question 7

Why malaria and mosquitoes are problematic.

Answer 7

Mosquitoes have developed resistance to insecticides so therefore it has become hard to regulate the spread and presence of malaria in Africa

Question 8

Solutions to the problem

Answer 8

1. Use less concentrated chemicals in order to impose less strong selection
2. Target the plants later in life so they are weaker for selection and thus do not have the ability to conform themselves to develop the resistance

Question 9

Drug Cocktails and HIV resistance

Answer 9

1. We use a multitude of drugs to target different areas of the HIV drug so that it would require a new complex adaptation for resistance

Question 10

Cycling HIV drugs

Answer 10

Cycling drugs when a person begins to develop resistance is crucial as you will be imposing various and alternating selection pressures and thus will cause the virus to have difficulty combating the drugs

Question 11

Chemotherapy Treatments and Drug Cycling

Answer 11

use different chemotherapy treatments as well as cycle drugs to ensure that resistance to drugs is limited and avoided

Question 12

Extinction

Answer 12

• The permanent elimination of the species
• 99% of the species that have been known have gone extinct
• more common in undistributed ecosystems

Question 13

Genetic Issues in Conservational Biology

Answer 13

1. Loss of genetic variation
2. Loss of heterozygosity
3. Inbreeding depression
4. Fixation of deleterious alleles
5. The inability of populations to adapt

Question 14

Problems with inbreeding depression

Answer 14

1. Can cause a severe reduction in population size and will eventually cause it to bottom out
2. Through environmental chances, hopefully a mutation will be introduced that will enable the population to recover

Question 15

How can an adaptation recover a population

Answer 15

Important factors include

1. Nature of mutation
2. The rate at which mutations are occurring
3. The size of the population
4. If there is the ecological opportunity for the adaptation to restore the balance of the population