Ch. 10 Natural Selection Flashcards Preview

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Flashcards in Ch. 10 Natural Selection Deck (27):
1

tuberculosis

single-celled bacterium. destroys lung tissue

2

antibiotics

kill certain nonhuman bacterial cells

3

antibiotic resistant

must use second-line drugs

4

MDR-TB

multi-drug resistant tuberculosis

5

XDR-TB

extensive drug resistant tuberculosis

6

natural selection

inference based on 4 observations:
1.individuals within populations vary
2. some variation may be inherited
3. populations produce more offspring than will survive
4. survival and reproduction are not random

7

individual in populations vary

dog may have litter with some black and some white

8

variant

each different type of individual in a population

9

some variation may be inherited

resemblance between parent and offspring

10

populations produce more offspring that will survive

trees make million of seeds every year. capacity for reproduction far outstrips the environmental resources

11

survival and reproduction are not random

some variants are more likely to survive. fitness and adaptations

12

fitness

relative survival and reproduction of one variant compared to others

13

adaptations

traits that increase fitness in a particular environment

14

inference

favorable inherited traits tend to increase over time while unfavorable traits are lost

15

artificial selection

selection imposed by human choice. deliberately control survival and reproduction of organisms with favorable traits to change the population

16

natural selection in lab

looking for adaptations of populations to environments manipulated in lab settings

17

natural selection in wild populations

examples are drug resistant pathogens and the bill size in galapagos finches in response to drought

18

modern synthesis

union between genetics and evolution. gene mutations provide the variation needed for evolution

19

subtleties of natural selction

doesn't cause evolution of perfect organisms.
1.cant make new traits arise
2. doesn't result in perfection. only improves fitness in the current environment
3.no progression toward a goal. only adapt to current environment

20

jury rigged design

adaptations using whatever underlying biology is available ('thumbs' on pandas)

21

directional selection

population traits move in a particular direction. typically leads to change in a population over time

22

stabilizing selection

populations tend to resist change in unchanging environments. the extreme variants are selected against and the average is in favor

23

diversifying selection

populations with 2 or more variants. likely if different subpopulations are experiencing different environments

24

tuberculosis and natural selection

1. bacteria in population vary, every time reproduction occurs mutation can happen
2. variation can be passed to offspring. drug resistant traits are coded in its DNA
3. more bacteria are produced than survive. antibiotic treatment eliminate the majority
4. survival isnt random. bacteria with traits making them more resistant are more likely to survive

25

drug resistance

patient stops treatment after symptoms are eliminated, leaving the more resistant bacteria still alive. the resistant strain reproduces and the disease returns and is much more difficult to control

26

stopping resistance

maintain drug therapy for several months, or use multiple drugs

27

combination drug therapy

drug cocktail therapy. the greater number of drugs used, the greater number of changes are required to become resistant