Ch. 6 Evolution And Ecology Flashcards Preview

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Flashcards in Ch. 6 Evolution And Ecology Deck (30)
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1

Biological evolution -

Change in populations of organisms over time

2

Genes can have two or more forms called ___.

Alleles

3

___ is the genetic makeup, and can be represented by letters, one for each allele.

Genotype

4

___ is a change in allele frequencies over time.

Evolution

5

Evolution can be defined more broadly as ___ ___ ___.

Descent with modification

6

Who used the phrase "descent with modification?"

Charles Darwin

7

Proposed populations change over time through ___ ___.

Natural selection

8

Individuals with certain __ __ survive and reproduce more successfully than individuals with other ___ ___.

Heritable characteristics

9

Natural selection requires three attributes:

- genetic variation
- variation must be heritable
- differential reproductive fitness related to this variation

10

Natural selection causes the two populations to ___ genetically over time.

Diverge

11

Natural selection acts only as a ___ ___.

Sorting process

12

Populations may evolve, but ..

Individuals do not evolve

13

Four key processes influence evolution:

- mutation
- natural selection
- genetic drift
- gene flow

14

Phenotype -

Observable characteristics of individuals that are determined by the genotype

15

Why is variation so important?

Natural selection acts upon variation

16

Different alleles arise by __.

Mutation

17

Mutation results from:

- copying errors during cell division
- mechanical damage
- exposure to certain chemicals
- exposure to high energy radiation

18

Homogeneity -

Lack genetic variation

19

Mutation is the "___ ___" of variation.

Raw material

20

__ is essentially a random process.

Mutation

21

Individuals in a population differ genetically because of both mutation and ___.

Recombination

22

Mutations occur too rarely to be direct cause of ___ ___ change.

Allele frequency change

23

Natural selection -

Occurs when individuals with particular heritable traits tend to leave more offspring than individuals with other heritable traits

24

What is the only process that consistently results in adaptive evolution?

Natural selection

25

Natural selection can be categorized into three types:

- directional selection
- stabilizing selection
- disruptive selection

26

Directional selection -

Individuals with one extreme of a heritable phenotypic trait are favored

Ex: drought favored large beak size in medium ground finches -> eating larger seeds

27

Stabilizing selection -

Individuals with an intermediate phenotype are favored

Ex: parasitic wasps select against small gall size, birds select against large gall size -> medium size galls

28

Disruptive selection -

Individuals at both phenotypic extremes are favored

Ex: African seedcrackers have two food sources -> really small seeds and really big seeds -> caused disruptive selection -> some birds got big beaks and some birds got small beaks

29

Altruism -

Helping others when it costs you

30

Typically there is a selfish interest called ___.

Cooperation