Chapter 7

Question 1

Define mutations

Answer 1

changes in genetic information (that are heritable)

Question 2

Genetic variation

Answer 2

• all species have genetic variation
• from sexual reproduction and mutations

Question 3

Neutral mutations + example

Answer 3

• most mutations are neutral
• a mutation that does not result in a selective advantage or disadvantage
• ie. black bears can carry the mutated gene that produces white bears

Question 4

Harmful mutations + example

Answer 4

• any mutations that reduce the reproductive success of an individual and are therefore selected against; harmful mutations do not accumulate over time
• ie. mutation that leads to genetic disorders

Question 5

Beneficial mutations + example

Answer 5

• any mutation that increases the reproductive success of an organism; favored by natural selection and accumulates over time
• ie. the sickle cell allele gives carriers a high degree of resistance to malaria and increases their chances of survival in regions with malaria

Question 6

Define domestication

Answer 6

the changing of members of a species to suit human needs through controlled breeding

Question 7

Define artificial selection

Answer 7

• directed breeding in which individuals that exhibit a particular trait are chosen as parents of the next generational
• used to produce new breeds of varieties of animals and plants

Question 8

Modern breeding

Answer 8

• using genetic engineering techniques to transfer beneficial genes from an individual of one species to another species
• GMO is then mass produced by cloning

Question 9

Advantages of selective breeding through artificial selection

Answer 9

• Allows humans to produce animals and crops with desirable traits
• Higher productivity and quality
• Crops can be selectively bred to be resistant to disease

Question 10

Disadvantages of selective breeding through artificial selection

Answer 10

• Limited by the genetic variability within the breeding population
• Can reduce the overall genetic diversity of the population and contribute to biodiversity loss

Question 11

Buffon

Answer 11

• Anatomical features that seemed to serve no purpose
• Species must have “improved” and “degenerated” after creation

Question 12

Carl Linnaeus - Systema Naturae

Answer 12

• Father of modern taxonomy (KPCOFGS)
• Life changed over time

Question 13

Erasmus Darwin

Answer 13

• Zoonomia
• All warm-blooded animals have arisen from one living filament
• life originates from a single source

Question 14

Jean-Baptiste Lamarck

Answer 14

• Theory of use and disuse: structures that are used become larger and strong, and structures that are not used become smaller and weaker
• Theory of inheritance of acquired traits: states that individuals could pass on characteristics to their offspring they acquired during their lives
• Lamarck’s theory is flawed
• features do not change in response to use ie. eyes
• characteristics acquired during an individuals lifetime does not change DNA so cannot be inherited
• contributions: all species evolve over time
• A species evolve in response to its environment
• changes are passed on from generation to generation

Question 15

Fossils

Answer 15

ancient remains, impressions, or traces of an organism or traces of its activity that have been preserved in rocks or other mineral deposits in Earth’s crust

Question 16

Georges Cuvier

Answer 16

Conducted first detailed studies of fossils
- Fossils from deeper layers were simpler than complex fossils above them
- rock layers contain fossils of many species that do not occur in layers above or below
- a theory that life had evolved from simple to more complex forms over time
- believed that species did not change
- catastrophism: pattern of fossils is by a series of global catastrophes

Question 17

Charles Lyell

Answer 17

Uniformitarianism: Geological changes are slow and gradual and neutral laws and processes have not changed

Question 18

Evidence of Evolution

Answer 18

• Biogeography
• Anatomical Features
• Embryology

Question 19

Biogeography

Answer 19

the scientific study of the geographic distribution of organisms based on both living species and fossils

Question 20

Darwin’s Hypothesis with the observation of many species of plants, birds, insects, and reptiles from the Galapagos Islands

Answer 20

Only these kinds of organisms are able to reach remote islands by crossing large expanses of open ocean

Question 21

Darwin’s Hypothesis with the observation of no native amphibians and very few land mammals from the Galapagos Islands

Answer 21

Amphibians and most mammals are unable to cross open ocean and will not be found on remote islands

Question 22

Darwin’s Hypothesis with the observation of many unique species found nowhere else on Earth from the Galapagos Islands

Answer 22

Over time, ancestral species have evolved into a new geographically isolated species

Question 23

Darwin’s hypothesis with the observation of unique species most closely resemble species on the nearest continental land mass

Answer 23

Unique species are descendants of ancestral species from the nearest continental land masses and will exhibit some similarites

Question 24

Homologous structures

Answer 24

• Different function (arm, leg, wing, fin)
  Same evolutionary origin / ancestor - divergent evolution
  Evolved from same material (bone) to accomplish different tasks
  ie. human and cat

Question 25

Analogous structures

Answer 25

- Same function (ie flight) - Different evolutionary origin (different common ancestors) - convergent evolution - different materials to accomplish the same tasks ie. butterfly wings and bat wings

Question 26

Vestigial Structures

Answer 26

- unused structures that were useful in a common ancestor but are no longer useful - not harmful and will be lost over time - often homologous to structure in a closely related species ie. wisdom teeth, appendix

Question 27

Embryology

Answer 27

- closely related organisms go through similar stages during their embryonic development - groups will diverge to take on distinct characteristics of their classes - common ancestors

Question 28

Transitional forms

Answer 28

Fossils or organisms that show the intermediate states between an ancestor and a descendant - provides evidence for change over time

Question 29

Molecular biology

Answer 29

- Percentage Similarity in DNA - similarity in amino acid sequences of particular proteins found in animal species

Question 30

Natural Selection

Answer 30

- the way nature favors the reproductive success of some individuals within a population over others - evolution was the result of natural selection over many generations and thousands of years - populations evolve, not individuals - produce an unlimited variety of species

Question 31

Survival of the Fittest + example

Answer 31

- the mechanism of natural selection - individuals who are best "fit" for the environment at the time will survive and pass on their genes - if the environment changes, traits that are "most fit" will change - does not always mean the biggest or strongest ie. faster cheetahs and stronger lions would have more offspring than slower and weaker individuals of the same species

Question 32

Adaptation

Answer 32

a characteristic or feature of a species that makes it well suited for survival or reproductive success in its environment - theory of evolution by natural selection could be extended to every adaptation

Question 33

Observations and Inferences (1-3) (Mechanism of Natural Selection)

Answer 33

1. In each generation, populations produce more offspring than there are adults 2. populations do not continue to grow in size 3. Food and many other resources are limited Inference: Individuals within a population compete for resources

Question 34

Observations and Inferences (4-5) (Mechanism of Natural Selection)

Answer 34

4. Individuals within all populations vary 5. May variations are heritable Inference: Some individuals will inherit characteristics that give them a better chance of surviving and reproducing

Question 35

Theory of Natural Selection

Answer 35

Over time the population changes as advantageous heritable characteristics become more common generation after generation

Question 36

Evolution of large-billed finches

Answer 36

Birds compete for medium sized seeds, and some large billed birds could feed on larger sized seeds. These larger billed birds have less competition, are healthier, lay more eggs, and offspring will most likely have larger bills. As this process is repeated after generations, number of larger billed birds increase.