Topic 6 Flashcards Preview

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Flashcards in Topic 6 Deck (32)
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1
Q

Evolution

A

change in the genetic composition of a population of a species over time

2
Q

The match of individuals to their environment is a product of..

A

the successes and failures of their ancestors

3
Q

The present form and function of individuals are..

A

specializations to their environment

4
Q

Adaptation

A

change in a genetically determined trait in response to environmental conditions that enhances the ability to cope w the environment

5
Q

Fitness

A

proportionate contribution of an individual to future generations

6
Q

Fitness involves

A
  • number of offspring produced

- number of offspring surviving to reproductive age

7
Q

Natural selection operates on

A

the individual

8
Q

Natural selection

A

differential success of individuals through interactions with their environment and other organisms

9
Q

Variation results in

A

differences in growth, survival and reproduction

10
Q

Fitness is measured by

A

the proportionate contribution an individual makes to future generations **

11
Q

In a given environment traits which enable individuals to grow, survive and reproduce are passed on to future generations and.. and without those traits they are..

A

selected FOR; selected AGAINST

12
Q

Selection pressures:

A
  • environment conditions (abiotic factors)

- species interactions (biotic factors)

13
Q

Selection pressures establish…

A

differences in fitness among individuals with different genotypes and phenotypes

14
Q

Selected adaptations typical allow for optimal performance under a certain set of environmental conditions but these often..

A

limit its performance under another set

15
Q

Genetic composition of the population..

A

changes over generations or evolves

16
Q

Assumptions

A
  • individuals of a species are not identical (genetic variation)
  • some of this variation is heritable
  • individuals leave different numbers of descendants (varying fitness)
  • fitness depends on interaction between individual’s trait and its abiotic/biotic environment
17
Q

Stabilizing selection

A

due to mendelian inheritance will maintain a diverse gene pool and evolution will not occur

18
Q

Directional selection

A

most common type pushing traits in one direction to drive evolution

19
Q

Disruptive selection

A

can lead to speciation

20
Q

Directional selection as commercial fishing exploitation

A

atlantic silverside experiments in lab and coming fish at random is better for natural selection

21
Q

Biological species concept

A

distinguish species based on their potential to interbreed and produce fertile offspring

22
Q

Speciation

A

implies that reproductive isolation (or genetic isolation) defines a species because reproduction is the means of transferring genetic information (DNA)

23
Q

Allopatric speciation

A

individuals are geographically isolated by a physical barrier (mountain). local environmental condition will cause different selective pressure leading to divergence

24
Q

Sympatric speciation

A

subpopulations are isolated without geological isolation (breeding time, etc)

25
Q

2 types of sympatric speciation

A
  • pre mating

- post mating

26
Q

Pre mating sympatric speciation

A

separation of mating events in space and time. behaviour (mating songs). mechanical or structural incompatibility

27
Q

Post mating sympatric speciation

A

reduced survival or reproductive success of offspring

28
Q

Cline

A

measurable, gradual, change over a geographic region in the average of some phenotypic character

29
Q

Clines are typically associated with..

A

environmental gradients in temp, moisture, light levels, altitude (ex white tailed deer)

30
Q

Ecotypes

A

population with an abrupt and dramatic difference in character due to influences associated within the species

31
Q

Genetic differentiation

A

if very little gene flow exists between populations the term subspecies is often used.

32
Q

Genetic differentiation is generally distinguished as..

A

different from other populations by 1 or more major characteristics (honey vs killer bee)