Exam 4

Question 1

Describe Lamarck’s theory of evolution through inheritance of acquired characteristics. Why was it incorrect.

Answer 1

Characteristics change because of the use or disuse of characteristics. It was incorrect because it is not based off of what actually occurs; heredity.

Question 2

Describe the importance of Darwin’s voyage abroad the HMS beagle to the development of his theory of evolution by natural selection

Answer 2

It allowed him to study plants in other countries.

Question 3

Describe the influences of Lyells principles of Geology and malthus’s essay on the principle of population on the development of darwins theory. Define malthusian catastrophe.

Answer 3

Lyell’s Principles of Geology: He stated that the earth was older than we thought. Opened up the possibilities of biodiversity over time.
Malthus’s Essay: People having more children than people dying, but the population stayed constant; because of the malthusian catastrophe. Darwin thought this could be happening with all living things.
Malthusian Catastrophe: War, famine, plague. Why the population stays constant

Question 4

define and describe artificial selection. Describe how artificial selection in domestic pigeons influenced darwins thinking

Answer 4

Artificial Selection: breeders choose mating pairs based on desired traits.
Darwin thought this could be happening in the natural world…natural selection.

Question 5

Describe the independent discovery of evolution by natural selection by wallace and his copresentation and copublication with darwin

Answer 5

They both had the same ideas and decided to write and manuscript together to the Royal Society and co publish it later on.

Question 6

Define and Describe priority with regard to scientific discovery

Answer 6

Priority is given to the first person to make a discovery or publish a theory.

Question 7

identify and describe the components of darwins theory of evolution by natural selection

Answer 7

1. Genetic Variation: there is a variety of phenotypes per trait (hair color, skin color)
2. Heredity: traits are heritable
3. Overproduction and competition: More offspring are being born than will reproduce and finite resources
4. Differential reproduction: some reproduce more than other, which makes those traits more common.

Question 8

describe the importance of the galapagos finches in the development of darwins theory

Answer 8

He was able to observe a variety of traits that each finch had acquired to adapt to their niche. They adapted to new environments.

Question 9

Describe the grant and grants studies of galapagos finches and their conclusions

Answer 9

They observe beak size. The average was larger in dry years and smaller in wetter years due to size of seeds.
Concluded that natural selection can occur rapidly.

Question 10

describe fossil evidence for evolution. Define transitional fossil. Describe archaeopteryx and tiktaalik as examples of transitional fossils

Answer 10

Transitional Fossil: a fossil with characteristics of both its ancestors and its descendants.
Fossils show evolution of a species over time.
Archaeopteryx represents todays birds with reptiles. Tiktaalik represents fish and amphibians.

Question 11

describe evidence for evolution from comparative anatomy. Define and compare homologous vs analogous structures

Answer 11

homologous: similar anatomy due to similar embryonic origin.
analogous: same function but have different structure and embryonic origin
homologous structure shows common ancestry between organisms due to similar embryonic development. Analogous structure demonstrate convergent evolution (two species adapt to solve a problem the same way)

Question 12

describe evidence for evolution from comparative embryology. Identify and describe the two structures found in all vertebrate embryos covered in class

Answer 12

pharyngeal pouch and postanal tail
similarities in embryonic development show common ancestry.

Question 13

describe molecular evidence for evolution, including examples from cytochrome c, hemoglobin, and the GLO gene

Answer 13

Few mutations occur
Cytochrome C: regularly accumulates mutations the further away from humans. Shows time since divergence.
Hemoglobin: Also reflects time since divergence
GLO gene: gene has been reactivated in some species.

Question 14

identify and describe common misconceptions about evolution. Explain why they are incorrect.

Answer 14

1. Evolution is just a theory: misunderstanding of the world theory.
2. Violates the second law of thermodynamics: evolution is in open system.
3. fossils don’t represent intermediates
4. mathematically improbable: probability is not an actual observation.
5. evolution drives to perfection: selects traits based on adaptability.
6. causes needed traits to appear: mutation appears at random.

Question 15

describe the modern synthesis of evolutionary biology and how evolution is defined according the modern synthesis

Answer 15

modern synthesis blended inheritance with evolution to better understand evolution at the molecular level. evolution can now be defined quantitatively due to Mendel’s calculations.

Question 16

describe hardy-weinburg equilibrium. Identify and describe the assumptions of Hardy-Weinburg equilibrium.

Answer 16

Allele frequencies remain constant (recessive don’t disappear and dominant don’t take over.) as long as certain assumptions are met
Assumptions:
1. large population
2. random mating
3. no mutation
4. no gain or loss of alleles through migration
5. no selective pressures

Under the equilibrium, allele frequencies and genotype frequencies add up to 100%.

Question 17

Describe how mutation produces evolutionary change

Answer 17

Mutation introduces new alleles.

Question 18

Describe how migration produces evolutionary change. Define and compare immigration vs. emigration

Answer 18

Migration transfers alleles to different locations. Changes allele frequencies.

Question 19

describe how genetic drift produces evolutionary change. Describe founder effect and bottleneck as examples of genetic drift mechanisms

Answer 19

genetic drift is random changes in allele frequencies. This can add too or remove a gene pool.
Founder effect: smaller population stems from a larger and shows less genetic variability.
Bottleneck: population declines drastically and then recovers causing less genetic diversity (natural selection)

Question 20

Describe how nonrandom mating, including inbreeding, produces evolutionary change.

Answer 20

Nonrandom: influences allele frequencies
inbreeding: doesn’t mix traits. Amplifies negative traits.

Question 21

describe how selection produces evolutionary change. Define and compare stabilizing, directional, and disruptive selection

Answer 21

stabilizing: favors intermediate phenotype (birth weight being similar to that of parents)
Disruptive: favors phenotype extremes, no intermediate.
Directional: distribution is pushed in direction.

Question 22

Define and describe heterozygote advantage and industrial melanism in terms of selection. Identify and describe examples of each

Answer 22

Industrial Melanism: easier to see/stand out and don’t survive as well. These organisms have more melanin than the typical color scheme. Peppered moth example.
Heterozygote Advantage: Heterozygote has a higher fitness than homozygote. Example, sickle cell trait protects against malaria in heterozygotes and causes the disease on homozygotes.

Question 23

Describe the endler guppy experiments and their conclusions

Answer 23

Guppies were placed in pools. 2 had no predators, 8 had two kinds. Guppies with pike were smaller and drab. Guppies with killifish were larger and more colorful.
Transplanted guppies from lower to upper became colorful. Predators drive selection.

Question 24

Define speciation. Identify and describe the three concepts used to define species that were discussed in class. Define and compare allopatric vs sympatric speciation

Answer 24

Speciation: population splits and becomes 2 interbreeding populations (allopatric is geographical separation and sympatric is no geographical separation)
typological, biological, and phylogenetic
Biological: Species mate with like species (reproductive isolation)

Question 25

define reproductive isolation. define and compare prezygotic vs postzygotic reproductive isolation. describe and compare the mechanisms of reproductive isolation.

Answer 25

Reproductive isolation: species mate with like species only.
Prezygotic: geographic isolation (allopatric speciation).
Postzygotic: a nonviable or sterile hybrid offspring is produced.

Question 26

Describe aristotle classified organisms

Answer 26

Aristotle classified plants on size and classified animals on where they lived and the color of their blood.

Question 27

describe the emergence of genus, the species, and the use of Latin names in classifying organism

Answer 27

Polynomial nomenclature came about when it was found that many species are similar but different. They used the genus name plus a description.

Question 28

define and describe polynomial nomenclature, including its disadvantages

Answer 28

polynomial: multiple names

Question 29

describe the two major contributions of linnaeus of taxonomy.

Answer 29

1. binomial nomenclature: genus + species epithet.
2. hierarchy based on characteristics

Question 30

Describe the construction and use of scientific names. explain the advantages of using scientific nomenclature vs. common names to identify organisms

Answer 30

we know exactly what organism we are talking about. One name can apply to multiple organisms, or multiple names can apply to one organism.

Question 31

identify and describe the hierarchical categories of Linnaean taxonomy

Answer 31

1. Life
2. Domain
3. Kingdom
4. Phylum
5. Class
6. Order
7. Family
8. Genus
9. Species

Question 32

Describe rays definition of species. Describe how it contributed to the biological species concept that emerged in the 1920s

Answer 32

Species are organisms that breed together and produce fertile offspring.
It laid the groundwork

Question 33

Define and describe the biological species concept, including its advantages and limitations

Answer 33

some hybrids are fertile.
doesn’t include asexual reproduction.

Question 34

define and describe the phylogenetic species concept, including its advantage and limitations

Answer 34

defines species by the evolutionary history and relationships among histories.
our knowledge and certainty is limited.

Question 35

Define and describe cladistics. Define clade. Define and compare derived vs ancestral characters

Answer 35

Cladistics: constructing phylogeny
Clade: organisms choses to compare.
Derived: differences that emerge as a result of evolution.
Ancestral:

Question 36

describe construction of cladogram. Define and compare outgroup vs ingroup. Describe weighting of derived characters

Answer 36

Outgroup: baseline for comparison
Ingroup: others being compared
Weighting: it reflects evolutionary significance. Important characteristics (backbone, birth)

Question 37

Describe traditional taxonomy. Compare traditional taxonomy of cladistics.

Answer 37

traditional: all characteristics. Gives richer picture
Cladistics better shoes evolutionary history.

Question 38

Describe the miller-urey experiment. Describe the primordial soup hypothesis, including its limitations and shortcomings. Describe lermans bubble hypothesis

Answer 38

simulated atmosphere and introduced energy and gasses. They let reactions continue for a while and found that macromolecules had formed.
Primordial soup: macromolecules that had developed through the experiment. Did life originate from this? Methane and ammonia were atmospheric gasses in the experiment, but in early time periods they would have been degraded.
Bubble hypothesis: methane and ammonia weren’t in the air they were in gas bubbles under the ocean.

Question 39

Describe the RNA world hypothesis on the origin of cells.

Answer 39

Cells originated from macromolecules. The first cells used RNA to pass on traits because it is simpler in structure, it can form structures with catalytic activity.

Question 40

describe the structures, motility, endospore production, and reproduction of prokaryotes. Compare prokaryote vs eukaryote

Answer 40

Structure: no organelles, simple chromosome as genome, ribosomes, capsule.
Motility: flagella
Endospore: formed by the water and coiled DNA. Bacteria splits inside cell wall and one engulfs the other.
Reproduction: binary fission or horizontal gene transfer

Question 41

describe the cell surfaces, motility, cyst formation, nutrition, reproduction, and multicellular forms amongst protists.

Answer 41

Cell surface: can be plant like, animal like, or different.
motility: extinction of cytoplasm (ameboid motility), some use flagella and cilia.
cyst formation: protects organism during non ideal environmental circumstances.
nutrition: some decompose, some hunt, some photosynthesize
reproduction: asexual, binary fission, or sexual.
multicellular forms: colonies

Question 42

Describe the structures, reproduction, nutrition, ecological importance as decomposers, and diversity of fungi. Compare fungi vs plants

Answer 42

structures: tubular structures rather than cells, mycelium threads
reproduction: nuclear mitosis (nuclear envelope remains intact). mushroom is reproductive structure
nutrition: decomposers
ecological importance as decomposers: digestive enzymes are released from mycelium; external digestion
diversity: unicellular, chytrids, Basidiomycota, ascidiomycota

Question 43

Describe sizes, biochemical composition, and structural diversity of viruses. Explain why they are not considering living. Describe and compare viral infection by bacteriophages vs animal viruses.

Answer 43

Sizes: vary (small, large)
Biochemical composition: genetic material (DNA or RNA), proteins that make capsid, Envelope
structural diversity: simple, complex, various enzymes may be included

No considered living because they don’t have cells. No homeostasis, metabolism, reproduction.

Bacteriophage vs animal virus: Bacteriophage recognize bacteria, injects genetic material into cell, cell makes copies of virus rather than its own protein. Cell ruptures and copies escape
Animal: viral particle connects to cell so its engulfed. DNA makes copies of virus, it explodes.