evolution quiz

Question 1

NATURAL SELECTION

Question 2

Evolution

Answer 2

is the change in gene frequency in a population over time.

Question 3

geologic theories - hutton and lyell

Answer 3

Hutton proposed that geologic features were explained by gradual, ongoing mechanisms

Lyell stated that mechanisms of change were constant over time in a theory known as uniformitarianism

Question 4

Lamarck’s Theory of Evolution

Answer 4

• Lamarck was the first to propose Theory of Effect of environment and new needs: The environment influences all organisms. A slight change in the environment brings about changes in organisms. This gives rise to new needs, which in turn produces new structures and changes the habits of organisms.
• Theory of Use & Disuse: parts that are used become larger and stronger while parts that are not used deteriorate
• Theory of Inheritance of Acquired Characteristics: organisms pass modifications made throughout their life onto their offspring
  It was WRONG, but his theory advanced discourse and provided a testable hypothesis for evolutionary change

Question 5

Darwin’s Theory of evolution

Answer 5

Influenced by all these theories:
- Evolution must be a gradual, continual, subtle process of change (Hutton, Lyell)
- Variation contributes to evolution through the inheritance of characteristics
(Lamarck)

Question 6

Evolution Is The Cumulative Change In The Heritable Characteristics Of A Population

Question 7

Natural Selection

Answer 7

A mechanism for change in populations that occurs when organisms with favorable variations for a particular environment survive, reproduce, and pass on these variations on to the next generation.

Natural selection acts on the phenotype (physical appearance), not the genotype (genetic makeup).

Question 8

Darwin’s Theory of Natural Selection

Answer 8

Adaptations: inherited characteristics of organisms that enhance their survival and reproduction in a specific environment

Natural Selection: process in which individuals that have certain, more desirable inherited traits survive and reproduce at higher rates than others that don’t have those traits

Used the term “descent with modification,” not “evolution”

Question 9

Natural Selection Steps

Answer 9

In order for natural selection to occur:
- Variation in adaptations within a species.
- Overproduction of offspring.
- Survival of the best adapted individuals.
- Best adapted individuals reproduce more successfully.

Question 10

Stipulations/Requirements for natural selection

Answer 10

Individuals do not evolve, only whole populations do.

Evolution only works on traits in which variations exist.

Natural selection must be studied in context of the environmental conditions as the adaptive value of traits shifts as conditions change.

Natural selection is not a creative mechanism. (Cannot cause adaptations or variations to occur, just selects for the best one that already exists in the environment)

Question 11

Differential reproduction

Answer 11

is the idea that those organisms best adapted to a given environment will be most likely to survive to reproductive age and have offspring of their own

Question 12

steps to adaptation

Answer 12

1. Overproduction
2. variation
3. selection
4. adaption

Question 13

Where Does Variation Come From?

Answer 13

Mutations:
- Random errors in DNA.
- Errors in mitosis & meiosis.
- Environmental damage.

Sexual reproduction:
- Mixing of alleles.
- Genetic recombination

Question 14

New alleles and fitness

Answer 14

New alleles that result in phenotypes with higher adaptive values will increase in frequency as natural selection occurs

The “fitness” of a given trait is relative to the selective pressures in its environment

Natural selection usually selects for the phenotypes that best improve an organism’s ability to reproduce (reproductive fitness)

Question 15

some mutations can influence the fitness of an organism, and these are known as beneficial or deleterious mutations. (e.g. butterfly)

Question 16

Fitness

Answer 16

measures an organism’s reproductive success

Question 17

Competition (darwin finches)

Answer 17

The competition that exists among offspring to survive limits survival of all offspring.

Competition for food, living space, and mates leads to adaptations of individuals.

Question 18

the environement

Answer 18

The environment in which a population of organisms’ lives can have a significant impact on the rate and direction of evolution.

A stable biotic (living) environment will have a lower rate of evolution since the selective pressures on the population are constant. (density-dependent)

Similarly, a stable abiotic (non-living) environment will have a lower rate of evolution. (density-independent)

Question 19

Selection

Answer 19

Selection acts on any trait that affects survival or reproduction

Question 20

Types of selection

Answer 20

Predation Selection Act On Both Predator and Prey (speed, behaviour, camaflouge, defenses)

Physiological selection - acts on body functions (disease resistance, protection from injury)

Sexual Selection: individuals with certain inherited characteristics are more likely to obtain mates than other individuals
Results in sexual dimorphism (differences between sexes in secondary sex characteristics)
Size, color, ornamentation, behavior, etc.
Intrasexual Selection: individuals of one sex (usually males) compete directly for mates
Intersexual Selection: individuals of one sex (usually females) choose a mate

Question 21

Sexual Selection Occurs When Certain Traits Increase Mating Success

Answer 21

attractiveness to potential mate
fertility of gametes
successful rearing of offspring

Question 22

Model of natural selection

Answer 22

GUPPIES!

Spots that help the guppy blend in with its surroundings protect it from predation — but spots that make it stand out help it attract mates.

Question 23

GENE POOL

Use “p” and “q” to represent the allele frequency in the population (percentage of each allele)

Answer 23

• Gene Pool: all the copies of every type of allele at every locus in all members of a population
• In diploid organisms, the gene pool is 2 times the number of alleles as there are individuals (each individual has 2 alleles)
• Fixed Alleles: only one allele exits in the gene pool – all members of the populations are homozygous for this allele

Question 24

Allele frequencies measure genetic variation.

Question 25

Individuals Can Respond To Environmental Changes (selective pressure)

Answer 25

As environments change, selective pressure favors organisms with adaptations that have increased fitness benefits.

This process helps to shape the characteristics of a population over time and can lead to the evolution of new species.

Question 26

Selective Pressures Vary

Answer 26

• Having a variety of different traits within a population is advantageous for survival because selective pressures vary (usually linked to the state of the ecosystem/environment).
• A condition that was previously deemed “advantageous” could become harmful to a population under new environmental conditions.
• The allele would then, theoretically, be selected against, and the number of individuals carrying that gene would begin to decrease.

Question 27

Allele Frequencies of Geographically Isolated Populations

Answer 27

Changes in allele frequency can reflect either random processes (genetic drift) or differential processes (natural selection)

Population bottlenecks and the founder effect will exacerbate genetic differences between geographically isolated populations

Question 28

Neo-Darwinism

Answer 28

The fusion of Mendelian genetics and Darwin’s natural selection

Darwin showed that evolution involves selection interacting with variation within populations
Mendel that the bases of this variation are discrete units of heredity (genes)

Question 29

natural selection

Natural selection acts on distributions of traits.

Answer 29

Only element of evolution where the outcome is NOT random

Increased frequency of “good” alleles over time

Acts on phenotype more than genotype
3 Types of Selection:
- Directional Selection: conditions favor one extreme of a phenotypic range
- Disruptive Selection: conditions favor both extremes of a phenotypic range
- Stabilizing Selection: conditions favor intermediates and select against extreme phenotypes
- Directional and Stabilizing reduce variation, Disruptive increases it

Question 30

natural vs artificial selection

Answer 30

Artificial Selection: nature provides variation, and humans select variations that we find useful (domestic animals and crops).

Artificial selection is the process of intentionally breeding organisms for specific traits. /manipulate phenotypic frequencies

Natural Selection: the environment is the selective force. Only those organisms that are well adapted will survive in the wild.