Evolution

Question 1

Pre-zygotic Barriers (Reproductive Isolation)

Answer 1

Interference with mating or fertilization if members of a different species try to mate.

Question 2

Post-zygotic Barriers (Reproductive Isolation)

Answer 2

Occurs after a member of a different species have mated with each other.

Question 3

Reproductive Isolation

Answer 3

To become a new species, a population must be reproductively isolated from the original population. This occurs by pre-zygotic and post-zygotic barriers.

Question 4

Bottleneck Effect (Genetic Drift)

Answer 4

Occurs when a populations size is drastically reduced such that the surviving population is not likely to represent the gene pool of the original population. This commonly occurs in populations following a natural event. (Earthquake, Floods, etc.)

Question 5

Founder Effect (Genetic Drift)

Answer 5

Occurs when a new colony is started by a few members of the original population. The small population may have reduced genetic variation from its original population.

Question 6

5 Major Causes of MICROevolution

Answer 6

• Mutation: A permanent change in the DNA. (Substitution, deletion, insertion)
• Gene Flow
• Genetic Drift
• Natural Selection
• Artificial Selection

Question 7

MICROEvolution

Answer 7

Refers to evolution within a species and reflects changes in allele frequencies within a population overtime.

Question 8

MACROevolution

Answer 8

Is evolution on a grand scale. Reflects the accumulation of multiple (micro)evolutionary changes over millions of years.

Question 9

Species

Answer 9

Morphological Speciation: based on similar anatomical features

Biological Speciation: based on fertility rather then physical similarity.

Question 10

Speciation

Answer 10

Process by which a new organism originates.

Involves the evolution of a population of organisms that are different enough to be classified in their own group.

Question 11

Hardy Weinberg Equilibrium

Answer 11

Used to calculate allele and genotype frequencies in a population. A population that is evolving is said to be in the Hardy Weinberg Equilibrium.

In order to be in HWE:
•random mating
•large population size
•no mutation, migration, or selection

Question 12

Vestigial Structures

Answer 12

A structure in an organism that has lost all or most of its original function in the course of evolution. Ex: tail bones

Question 13

Homologous Structure

Answer 13

An example of an organ or bone that appears in different animals.

Question 14

Analogous Structures

Answer 14

Shows the various structures in different species, having the same function but has evolved separately. They do not share common ancestors.

Question 15

Common Proteins

Answer 15

Analyze: enzymes in saliva that break down starch into sugar.

Lipase: breaks down fats.

Pepsin: breaks down protein into fats.

Question 16

Similarities in DNA sequences

Answer 16

The process of determining the precise order of nucleotides within lab a DNA molecule.

Question 17

Artificial Selection

Answer 17

Intentional breeding of domestic plants and animals to select certain desired traits.

Question 18

Natural Selection

Answer 18

Is the only cause of microevolution that allows a population to adapt to its environment.

3 ways:

Stabilizing Selection
Directional Selection
Distributive Selection

Question 19

Gene Flow

Answer 19

Gene Flow is the movement of alleles into or out of a gene pool. Migration into or out of a population may be responsible for a marked change in allele frequencies.

Question 20

Sexual Selection

Answer 20

Is a special type of natural Selection. There are two types:

Intraselection: Selection with the same sex due to competition of mates of the opposite sex.

Intersection: Selection where individuals of one sex are picky on their choice of mates of opposite sex.

Question 21

Post-zygotic Barriers

Answer 21

Occurs after members of different species have mated with each other.

Reduced Hybrid Viability: abort development of hybrid at some embryonic stage.

Reduced Hybrid Fertility: doesn’t produce fertile gametes in vigorous hybrids.

Question 22

Pre-Zygotic Barriers

Answer 22

Interferes with mating or fertilization if members of different species try to mate.

Habitat isolation 
Temporal Isolation 
Behavioral isolation
Mechanical isolation 
Gamete isolation

Question 23

Modes of Speciation

Answer 23

Allopathic Speciations: Speciation that takes place when populations inhabit geographically separate ranges gene Flow between populations stops, new species evolve.

Sympatric Speciation: Speciation that takes place in geographically overlapping populations.
Takes place in geographically overlapping populations. Can occur be chromosomal changes and non-random mating.

Question 24

Proteins

Answer 24

Made of hundreds of units called amino acids. They are required for structure, function, and regulation of the body’s tissue and organs.

Question 25

Transitional Fossils

Answer 25

Any fossilized remains of a life form that exhibits traits common to both ancestral group and it’s derived descendent group.

Question 26

Geographical Isolation

Answer 26

Is the result of an accident or coincidence.

Question 27

Fossils

Answer 27

The remains or impressions of a prehistoric organism preserved in a petrified form or as a mold or cast in rock.

Question 28

Evolution

Answer 28

Refers to genetic changes in a population over time.

Question 29

Index Fossils

Answer 29

A fossil that is useful for dating and correlating the strata in which it’s found.

Question 30

Darwins Conclusions

Answer 30

Organisms produce more offspring than can survive. Therefore, there is more competition for limited resources.

Variations exist among individuals of a population, and much of this variation is heritable.

Individuals that are better suited to their environment survive to produce more offspring, passing their characteristics to the next generation.