First Exam

Question 1

Evolutionary population

Answer 1

When a Group of the same organisms Gene pool changes and they go through evolutionary change.

Question 2

Microevolution

Answer 2

Change in gene pool. Ex: frequency of alleles due to an individual phenotypic traits that are better to survive and reproduce. How biotic and abiotic selective agents change the gene pool with each generation.

Question 3

Phenotypes

Answer 3

Observable, measurable characteristics of organisms. Hi eggy, eye color and blood type

Question 4

Natural selection-

Answer 4

The major process that changes gene pools in nature. Expect to occur in all populations. It is a law of nature.

Question 5

Artificial selection

Answer 5

Humans choose which animals or plants to breed because they want a desirable characteristics. Goal of developing particular phenotypic characteristics. Pg 41

Question 6

Relative fitness

Answer 6

Genetic contribution (typically the number of surviving offspring) of an individual to succeeding generations. Compared to surviving offspring of other members of species.

Question 7

Components of fitness

Answer 7

Growth, survival and reproduction.

Question 8

Agents of selection

Answer 8

Any environmental factor that causes variation in survival and reproduction of individuals. Agent of natural selection. Can be abiotic (climate: rain fall, temp, light availability. Edaphic: soil minerals soil PH, soil moisture) and biotic (macroscopic- competitor inter and intraspecific) pg 8

Question 9

G x E

Answer 9

When two or more genotypes react to an environmental factor in different ways. A norm or reaction graph is used to display the genotypes reactions. Fig 2.3 dandelion in mown vs unmown habitats

Question 10

Directional selection

Answer 10

Mean changes over time. Phenotypes with larger or smaller values of the trait show greater relative fitness and are thus favored by selection. Pg 22
Changes in weather, climate or food availability lead to directional selection.

Question 11

Contemporary evolution

Answer 11

Evolution which occurs in less then 100 years

Question 12

Stabilizing selection

Answer 12

Favors the average individuals in a population. Mean does not change. Selects against extreme Phenotypes and favors those adapted to the environment.

Question 13

Disruptive selection

Answer 13

Phenotypes with the intermediate trait values show the lowest relative fitness. Natural selection favors extreme variations of a trait. Pg 22 can lead to two distinct groups

Question 14

External vs internal

Agents of selection

Answer 14

External factors- outside the organism ex: soil ph

Internal agents- selection pressures derive from the internal dynamics of a functioning organisms. bio chemicals, growth factors and living endosymbiotic microbes

Question 15

Selection differential

Answer 15

Simple linear regression. Measure of the intensity of selection. Covariance of fitness with trait values.
Fitness function

Question 16

Selection gradient

Answer 16

Statistical correlation of trait you are interested in vs. other traits you measured

Question 17

Path analysis

Answer 17

Uses multiple regression on different phenotypic traits correlated with the trait of interest and also inter correlated (among themselves) . Promise for improving the understanding of selection by permitting a way to evaluate different hypothesizes causal pathways of selection.

Question 18

Natural experiments pg 39

Answer 18

Usually studies a distinct recognizable phenotypic variant that already exist in one or more populations. No selective agents are manipulated, fitness of discrete Phenotypes is monitored under natural conditions. You see different phenotypic traits in population.

Question 19

Common Garden

Answer 19

Grow organisms in homogenous common environment to reveal possible genetic/phenotypic differences and indicates much potential for natural selection to cause evolutionary change. In populations, families, clones, ecotypes.

Question 20

“In vitro” ecology

Answer 20

Study of ecotypic differentiation.
Can be useful in identifying and evaluating specific genotypes, populations and ecotypes of a particular plant species in terms of their life history features. Pg 46 corms on trees.

Question 21

Single garden experiment

Answer 21

Has been used a long time in plant ecology history. Can show certain results if environmental factors are varied experimentally. Do not allow the detection of pop by env interactions. Can show different variations in pop from a common env.

Question 22

Ecotype

Answer 22

A genetically distinct population of plants, animals or organisms that are found in a particularly habitat adapted to specific to environment.

Question 23

Turesson

Answer 23

1920s in Sweden, he came up with the Ecotype concept (locally adapted population that show distinct phenotypic traits)

Question 24

Geographic cline

Answer 24

When a species or Ecotype has specific phenotype or genetic trait due to geographic area.

Question 25

Multiple gardens

Answer 25

No env. Factors varied. Can measure population (or genotype) by environmental interaction.
Eg) Clausen, Keck and Heisy Sierra Nevada three common gardens different elevations. Learn GxE interactions, important to understand evolution of local adaption.

Question 26

Home- site advantage

Answer 26

Garden population did best when conditions matched original/ home environment. Mostly climate situations

Question 27

Multiple common gardens one or more env factors varied

Answer 27

Usually env. Factors thought to be important selection agents are varied by experiments. Expected pop. To perform beat when exposed to conditions similar to their original “home” environment.
Agents responsible for adaptive differentiation of populations.

Question 28

Blocking. Block-type experimental designs

Answer 28

To control for possible unidentified variation in environmental conditions within a common garden. Treating statically heterogeneity as an effect in an analysis of variance. One part of the garden can have different factors than another. Such as sun hours or soil minerals.

Question 29

Questions and considerations in using common garden experiments

Answer 29

1. what to use: seeds, seedling or ramets?
2. control for “maternal effects?
3. How many gardens? Where will they be places?
4. What sample sizes to use?
5. Will “blocks” be used to control heterogeneity?
6. Will naturally occurring vegetation be removed or not?
7. Will climate/env data be obtained from poo source regions?
8. Will any env variables by purposely manipulated?

Question 30

Usefulness and applications of common garden technique pg 65

Answer 30

• investigation of invasive plants, can reveal which phenotypic traits are under selection and likely to be important to invasion success.
• adaption to climate change- expect plant from southern pop to be well suited for increasing temps
• study hybrid fitness
• testing effects of genetically engineered crops and their wild hybrids

Question 31

Reciprocal transplant experiments

Answer 31

Used mostly to examine “local adaption”. If a population is adapted to local/home conditions, if some of these individuals are transplanted into an “alien” habitat to which they are not adapted will show reduced survival, growth and/or reproduction relative to their natural home performance.

Question 32

Adaption

Answer 32

A process that results from the effect of natural selection in a phenotype pool.

• reveal adaptive evolution by natural selection- population specific result -pg 68
• character adaptions- adaption refers to a trait that improves the fitness of individuals that have it relative to other that do not.

Question 33

Genetic drift

Answer 33

Changes in genes or alleles do to something random. Has nothing to do with natural selection. Random chance fluctuations in a gene pool. Results in reduction of genetic variation (genetic erosion). Ex: migration
Also- bottleneck, founder effect and habitat fragmentation.

Question 34

Gene flow

Answer 34

Migration of individuals/ genes in gamates, pollen, seeds between populations. Immigration into pop and emigration out of pop: changes the gene pool for both pops. Gene pools homogenize reduce likelihood of pop adaption.

1. Size of migrant pop relative to recipient pop
2. gene pool (allele freq) of migrant pop and how much it differed from the recipient pop

Question 35

The demonstration of local adaption depends on:

Answer 35

• how env different are the habitats the source pops live in? The more diff the env the more different the selection pressures leading to adaption.
• how far apart or the transplant sites
• what is transplanted (seeds, seedling)?
• which env factors will be manipulated for investigation
• what kind of ecological data are measured? Focus on fitness
• what is the duration of the study?