evolution

Question 1

What is evolution?

Answer 1

Change over time, specifically a change in the number of times specific genes that code for specific characteristics occur within an interbreeding population.

Question 2

Do individuals or populations evolve?

Answer 2

Populations evolve, not individuals.

Question 3

Is there an implied improvement in evolution?

Answer 3

No, there is no implied ‘improvement’ in evolution.

Question 4

Do organisms change because they want or need to?

Answer 4

No, they change due to random change.

Question 5

Who was Lamarke

Answer 5

A scientist who believed that features could be gained or lost through use or disuse, and these traits could be passed to offspring (1801).

Question 6

What is the Inheritance of Acquired Characteristics?

Answer 6

The concept proposed by Lamarck that traits gained or lost could be passed to offspring.

Question 7

Who is credited with studying and explaining evolution?

Answer 7

Charles Darwin.

Question 8

What concept did Darwin develop in 1844?

Answer 8

The driving force for evolution, known as Natural Selection.

Question 9

What is Natural Selection?

Answer 9

The process whereby organisms better adapted to their environment tend to survive and produce more offspring.

Question 10

What are Darwin’s first two observations?

Answer 10

1) Organisms produce more offspring than can survive to adulthood. 2) There is variability among species, and this variability is passed from one generation to the next.

Question 11

What is Darwin’s inference from his observations?

Answer 11

Individuals who inherit characteristics most fit for their environments are likely to produce more offspring than less fit individuals.

Question 12

What is fitness in the context of evolution?

Answer 12

The ability to survive and produce offspring who can also survive and reproduce.

Question 13

What is required for evolution by natural selection?

Answer 13

Genetic variation, one or more phenotypes are more suited to environment, these produce more offspring

Question 14

How is genetic variation added to genotypes?

Answer 14

Genetic variation is added to genotypes by mutations.

Question 15

What are mutations?

Answer 15

Mutations are any changes in DNA.

Question 16

What do mutations lead to?

Answer 16

Mutations lead to changes in the phenotype.

Question 17

What is a phenotype?

Answer 17

A phenotype is the observable characteristics of an organism.

Question 18

What acts upon the phenotype?

Answer 18

Natural selection acts upon the phenotype.

Question 19

What happens to individuals more suited to the environment?

Answer 19

Individuals more suited to the environment produce more offspring.

Question 20

What do individuals contribute to the gene pool?

Answer 20

Individuals contribute more to the total gene pool of the population.

Question 21

What changes over time in a population?

Answer 21

The population’s gene pool changes over time.

Question 22

What is speciation?

Answer 22

Speciation is the creation of a new species.

Question 23

When may speciation occur?

Answer 23

Speciation may occur if geographic and reproductive isolating mechanisms exist.

Question 24

What is Directional Selection?

Answer 24

An extreme phenotype (very long or very short, etc.) is a favourable adaptation.

Question 25

What is Stabilizing Selection?

Answer 25

-The average phenotype is a favourable adaptation, while extreme phenotypes are unfavourable. -Operates most of the time in populations.

Question 26

What is Disruptive Selection?

Answer 26

The most rare type of selection where two opposite extreme phenotypes are favourable over the average phenotype.

Question 27

what are the other types of selection

Answer 27

sexual, artificial, and genetic drift

Question 28

what is sexual selection

Answer 28

selection through preference by one sex for certain characteristics

Question 29

what is artificial selection

Answer 29

selecting traits based on what humans find desirable in another species

Question 30

what are the types of sexual selection

Answer 30

Intersexual selection- “female choice” female invest a lot of time in their offspring and want to ensure their offspring have the best genes Intrasexual selection -“male-male” competition, members of the same sex fight for access to members of the opposite sex

Question 31

what is genetic drift

Answer 31

genes in a population change due to random chance

Question 32

what are the types of genetic drift

Answer 32

bottleneck effect- random event wipes out a large chunk of population founder effect- individuals from a population break off and form their own population gene flow- individuals from one population move into another population

Question 33

what is antibiotic resistance

Answer 33

the ability of bacteria to survive exposure to antibiotic srugs

Question 34

what is the process of antibiotic resistance

Answer 34

-bunch of bacteria including a resistant variety -get bathed in antibiotics, most normal bacteria die -the resistant bacteria multiply and become more common -eventually the entire infection evolves to a resistant strain

Question 35

how to prevent antibiotic resistance

Answer 35

-don’t overuse antibiotics or use them to treat viral infections -practice good hygiene -take all antibiotics -don’t use antibiotics for preventive measures

Question 36

what is speciation

Answer 36

evolutionary formation of new species -if groups of organisms are reproductively isolated from other groups they could evolve independently and become different species

Question 37

what are reproductive isolating mechanisms

Answer 37

any behavioural, structural, or biochemical trait that prevents individuals from reproducing successfully together

Question 38

what are the two major types of reproductive isolation

Answer 38

prezygotic- prevention of mating or fertilization postzyogtic-prevent maturation and reproduction in offspring from interspecies mating

Question 39

what are the types of prezygotic isolation

Answer 39

ecological-different habitats or niches temporal-different reproductive cycles (time of day, seasons) behavioural- don’t respond to each others mating rituals mechanical- structural differences prevent exchange of alleles genetic - sperm and eggs are exchanged but chemical markers prevent fertilization

Question 40

what are the types of post zygotic isolation

Answer 40

zygotic mortality- species can mate but no embryos develop to maturity hybrid inviability- baby hybrids aren’t viable hybrid infertility- baby hybrids viable but not fertile

Question 41

what is convergent evolution

Answer 41

-evolution toward similar traits in unrelated species, same function in unrelated species

Question 42

what is convergent evolution

Answer 42

-evolution toward similar traits in unrelated species, same function in unrelated species

Question 43

divergent evolution

Answer 43

-evolution towards different traits in closely related species -organisms share a common ancestor -rapid divergent evolution is called adaptive radiation

Question 44

coevolution

Answer 44

species evolve in response to changes in each other -can occur in beneficial or competitive relationships

Question 45

punctuated equilibrium

Answer 45

evolution is stable for a time and suddenly new forms appear -occurs in areas where environmental conditions change rapidly

Question 46

extinction

Answer 46

background extinction-occurs continuously at a low rate, affects a few species in a small area, due to local environmental changes mass extinction- destroy many species at a global level, caused by catastrophic events