BIOS 209 - Ch 1, 18 - 20

T/F - Scientific knowledge is complete

T/F - Scientific knowledge is complete

False

T/F - Prokaryotic organisms have a nucleus

False

T/F - Eukaryotic organisms have organelles

True

T/F - All cells are bound by a membrane

True

T/F - Darwin utilized deductive reasoning to build his theory of Evolution by natural selection

False

T/F - A scientific theory means that the information known related to the theory to date is false

False

T/F - Mary Anning sold seashells by the seashore as an early paleologist.

True

T/F - The Earth’s continents were once stuck together allowing animals to move from Australia to North America by land

True

T/F - Evolution of new species only occurs over a very, very long time

False

T/F - Moderns humans are a mix of multiple hominid relatives.

True

What was the contribution to the tree of life from the scientific research of Woese and Fox? What molecule did they examine?

They used ribosomal rRNA sequences to analyze the evolutionary relationships among organisms. Their research led to the discovery that life is divided into three domains: Eukarya, Prokarya, and they identified the third, Archaea.

What does a ribosome do in the cell?

Protein assembly

What was the contribution to the tree of life from the scientific research of Castelle and Banfield, 2016? What molecule did they examine?

In their 2016 research, Castelle and Banfield expanded the tree of life by using genomic data from over 1,000 uncultivated organisms. They examined DNA to uncover new microbial groups and their evolutionary relationships.

Darwin’s ‘Descent with Modification’ really entails what four main components about populations of organisms and their interactions with the environment?

1. Populations are variable, and population sizes are stable

2. More offspring are produced than can survive; there is intense competition for resources

3. Characteristics of offspring vary, and these variations are heritable

4. Characteristics that benefit individuals in an environment, help survival, characteristics are altered in a population over time

Do individual organisms evolve?  Can individual organisms adapt to their environments?

Associated with this, what is acclimation vs. adaptation?

No, populations evolve.  No organisms can’t adapt.  Organisms can acclimate to their environment but common English uses the two terms (adapt and acclimate) equally.  So acclimation is adjusting to the environment, adapt really should be reserved for physical/physiological changes to better survive in an environment.

Allopatric speciation

Allopatric speciation is the process of speciation that occurs when populations of a species become geographically isolated. This isolation prevents gene flow between the populations, leading to evolutionary divergence due to natural selection, genetic drift, and mutation over time.

Sympatric Speciation

Sympatric speciation is the process by which new species evolve from a single ancestral species while inhabiting the same geographic region. This can occur through mechanisms such as polyploidy, sexual selection, or ecological niche differentiation, allowing populations to diverge without physical barriers.

What are homologous structures? How do homologous structures support the theory of evolution?

Homologous: descent with modification; similar bones/structures found in different organisms; more closely related organisms share more common features of structure, physiology, behavior, etc.

Other evidence: Divergent vs convergent evolution,Vestigial structures,Fossil record, Biogeography, Molecular Biology

The first forms of life on Earth were ________.

1. plants

2. microorganisms

3. birds

4. dinosaurs

Microorganisms

A suggested and testable explanation for an event is called a ________.

1. hypothesis

2. variable

3. theory

4. control

Hypothesis

Which of the following sciences is not considered a natural science?

1. biology

2. astronomy

3. physics

4. computer science

Computer science

The type of logical thinking that uses related observations to arrive at a general conclusion is called ________.

1. deductive reasoning

2. the scientific method

3. hypothesis-based science

4. inductive reasoning

Inductive reasoning

The process of ________ helps to ensure that a scientist’s research is original, significant, logical, and thorough.

1. publication

2. public speaking

3. peer review

4. the scientific method

peer review

The smallest unit of biological structure that meets the functional requirements of “living” is the ________.

1. organ

2. organelle

3. cell

4. macromolecule

cell

Viruses are not considered living because they ________.

1. are not made of cells

2. lack cell nuclei

3. do not contain DNA or RNA

4. cannot reproduce

cannot reproduce

The presence of a membrane-enclosed nucleus is a characteristic of ________.

1. prokaryotic cells

2. eukaryotic cells

3. living organisms

4. bacteria

eukaryotic cells

A group of individuals of the same species living in the same area is called a(n) ________.

1. family

2. community

3. population

4. ecosystem

population

Which sequences represents the hierarchy of biological organization from the most inclusive to the least complex level?

1. organelle, tissue, biosphere, ecosystem, population

2. organ, organism, tissue, organelle, molecule

3. organism, community, biosphere, molecule, tissue, organ

4. biosphere, ecosystem, community, population, organism

biosphere, ecosystem, community, population, organism

Where in a phylogenetic tree would you expect to find the organism that had evolved most recently?

1. at the base

2. within the branches

3. at the nodes

4. at the branch tips

at the branch tips

Which scientific concept did Charles Darwin and Alfred Wallace independently discover?

1. mutation

2. natural selection

3. overbreeding

4. sexual reproduction

natural selection

Which of the following situations will lead to natural selection?

1. The seeds of two plants land near each other and one grows larger than the other.

2. Two types of fish eat the same kind of food, and one is better able to gather food than the other.

3. Male lions compete for the right to mate with females, with only one possible winner.

4. all of the above

Male lions compete for the right to mate with females, with only one possible winner.

Which description is an example of a phenotype?

1. A certain duck has a blue beak.

2. A mutation occurred to a flower.

3. Most cheetahs live solitary lives.

4. both a and c

both a and c

Which situation is most likely an example of convergent evolution?

1. Squid and humans have eyes similar in structure.

2. Worms and snakes both move without legs.

3. Some bats and birds have wings that allow them to fly.

4. all of the above

all of the above

Which situation would most likely lead to allopatric speciation?

1. Flood causes the formation of a new lake.

2. A storm causes several large trees to fall down.

3. A mutation causes a new trait to develop.

4. An injury causes an organism to seek out a new food source.

Flood causes the formation of a new lake.

What is the main difference between dispersal and vicariance?

1. One leads to allopatric speciation, whereas the other leads to sympatric speciation.

2. One involves the movement of the organism, and the other involves a change in the environment.

3. One depends on a genetic mutation occurring, and the other does not.

4. One involves closely related organisms, and the other involves only individuals of the same species.

One involves the movement of the organism, and the other involves a change in the environment.

Which variable increases the likelihood of allopatric speciation taking place more quickly?

1. lower rate of mutation

2. longer distance between divided groups

3. increased instances of hybrid formation

4. equivalent numbers of individuals in each population

longer distance between divided groups

What is the main difference between autopolyploid and allopolyploid?

1. the number of chromosomes

2. the functionality of the chromosomes

3. the source of the extra chromosomes

4. the number of mutations in the extra chromosomes

the source of the extra chromosomes

Which reproductive combination produces hybrids?

1. when individuals of the same species in different geographical areas reproduce

2. when any two individuals sharing the same habitat reproduce

3. when members of closely related species reproduce

4. when offspring of the same parents reproduce

when members of closely related species reproduce

Which condition is the basis for a species to be reproductively isolated from other members?

1. It does not share its habitat with related species.

2. It does not exist out of a single habitat.

3. It does not exchange genetic information with other species.

4. It does not undergo evolutionary changes for a significant period of time.

It does not exchange genetic information with other species.

Which situation is not an example of a prezygotic barrier?

1. Two species of turtles breed at different times of the year.

2. Two species of flowers attract different pollinators.

3. Two species of birds display different mating dances.

4. Two species of insects produce infertile offspring.

Two species of insects produce infertile offspring.

Which term is used to describe the continued divergence of species based on the low fitness of hybrid offspring?

1. reinforcement

2. fusion

3. stability

4. punctuated equilibrium

reinforcement

Which components of speciation would be least likely to be a part of punctuated equilibrium?

1. a division of populations

2. a change in environmental conditions

3. ongoing gene flow among all individuals

4. a large number of mutations taking place at once

ongoing gene flow among all individuals

If a person scatters new seeds in one area (ex for restoration work along Watson Creek), how would natural selection work in this situation?

The plants that can best use the resources of the area, including competing with other individuals for those resources will produce more seeds themselves and those traits that allowed them to better use the resources will increase in the population of the next generation.

Why do scientists consider vestigial structures evidence for evolution?

Vestigial structures are considered evidence for evolution because most structures do not exist in an organism without serving some function either presently or in the past. A vestigial structure indicates a past form or function that has since changed, but the structure remains present because it had a function in the ancestor.

Explain why the statement that a monkey is more evolved than a mouse is incorrect.

The statement implies that there is a goal to evolution and that the monkey represents greater progress to that goal than the mouse. Both species are likely to be well adapted to their particular environments, which is the outcome of natural selection.

Why do island chains provide ideal conditions for allopatric speciation (ex. adaptive radiation) to occur?

Organisms of one species can arrive to an island together and then disperse throughout the chain, each settling into different niches and exploiting different food resources to reduce competition.

Two species of fish had recently undergone sympatric speciation. The males of each species had a different coloring through which the females could identify and choose a partner from her own species. After some time, pollution made the lake so cloudy that it was hard for females to distinguish colors. What might take place in this situation?

It is likely the two species would start to reproduce with each other. Depending on the viability of their offspring, they may fuse back into one species.

Why can polyploidy in individuals lead to speciation fairly quickly?

The formation of gametes with new n numbers can occur in one generation. After a couple of generations, enough of these new hybrids can form to reproduce together as a new species.

What do both rate of speciation models (ex. gradual vs. punctuated) have in common?

Both models continue to conform to the rules of natural selection, and the influences of gene flow, genetic drift, and mutation.

Describe a situation where hybrid reproduction would cause two species to fuse into one (hint: warming planet where Grizzly and Polar Bears coexist in an ecosystem).

If the hybrid offspring are as fit or more fit than the parents, reproduction would likely continue between both species and the hybrids, eventually bringing all organisms under the umbrella of one species.

T/F - Individual organisms evolve but don’t acclimate to an environment

False

T/F - Population genetics studies how selective forces change the allele frequencies in a population over time

True

Mutations in a population are created in direct response to selective pressure

False

T/F - Adding all allele frequencies observed in a population should equal 1 or 100%

True

T/F - Populations bottlenecks, i.e. founder’s effects, increase genetic variation in the population

False

T/F - A violation of the Hardy-Weinberg equilibrium is necessary for evolution to occur

True

T/F - All taxonomy uses systematics as its main principle to determine phylogeny.

False

T/F - Genetic variation, alleles, may be lost due to random chance in small populations

True

T/F - A mutation that increases fitness in one environment will increase fitness in all environments equally

False

T/F - Evolution is directional and always moves towards more complex forms

False

T/F - Unrelated organisms may share DNA, a process described as vertical gene transfer

False

T/F - The origin of life on Earth is known

False

T/F - The biological species concept works well for single celled organisms

False

What is the difference between micro- and macroevolution?
a. Microevolution describes the evolution of small organisms, such as insects, while macroevolution describes the evolution of large organisms, like people and elephants.
b. Microevolution describes the evolution of microscopic entities, such as molecules and proteins, while macroevolution describes the evolution of whole organisms.
c. Microevolution describes the evolution of organisms in populations, while macroevolution describes the evolution of species over long periods of time.
d. Microevolution describes the evolution of organisms over their lifetimes, while macroevolution describes the evolution of organisms over multiple generations.

c. Microevolution describes the evolution of organisms in populations, while macroevolution describes the evolution of species over long periods of time.

Population genetics is the study of:
a. how selective forces change the allele frequencies in a population over time
b. the genetic basis of population-wide traits
c. whether traits have a genetic basis
d. the degree of inbreeding in a population

a. how selective forces change the allele frequencies in a population over time

Which of the following populations is not in Hardy-Weinberg equilibrium?
a. a population with 12 homozygous recessive individuals (yy), 8 homozygous dominant individuals (YY), and 4 heterozygous individuals (Yy)
b. a population in which the allele frequencies do not change over time
c. p2 + 2pq + q2 = 1
d. a population undergoing natural selection

d. a population undergoing natural selection

17. One of the original Amish colonies rose from a ship of colonists that came from Europe. The ship’s captain, who had polydactyly, a rare dominant trait, was one of the original colonists. Today, we see a much higher frequency of
polydactyly in the Amish population. This is an example of:
a. natural selection
b. genetic drift
c. founder effect
d. b and

c. founder effect

When male lions reach sexual maturity, they leave their group in search of a new pride. This can alter the allele frequencies of the population through which of the following mechanisms?
a. natural selection
b. genetic drift
c. gene flow
d. random mating

c. gene flow

Which of the following evolutionary forces can introduce new genetic variation into a population?
a. natural selection and genetic drift
b. mutation and gene flow
c. natural selection and nonrandom mating
d. mutation and genetic drift

b. mutation and gene flow

What is assortative mating?
a. when individuals mate with those who are similar to themselves
b. when individuals mate with those who are dissimilar to themselves
c. when individuals mate with those who are the most fit in the population
d. when individuals mate with those who are least fit in the population

a. when individuals mate with those who are similar to themselves

When closely related individuals mate with each other, or inbreed, the offspring are often not as fit as the offspring of two unrelated individuals. Why?
a. Close relatives are genetically incompatible.
b. The DNA of close relatives reacts negatively in the offspring.
c. Inbreeding can bring together rare, deleterious mutations that lead to harmful phenotypes.
d. Inbreeding causes normally silent alleles to be expressed

c. Inbreeding can bring together rare, deleterious mutations that lead to harmful phenotypes.

When males and females of a population look or act differently, it is referred to as ________.
a. sexual dimorphism
b. sexual selection
c. diversifying selection
d. a cline

a. sexual dimorphism

The good genes hypothesis is a theory that explains what?
a. why more fit individuals are more likely to have more offspring
b. why alleles that confer beneficial traits or behaviors are selected for by natural selection
c. why some deleterious mutations are maintained in the population
d. why individuals of one sex develop impressive ornamental traits

d. why individuals of one sex develop impressive ornamental traits

Compare microevolution to macroevolution using humans as a model (example) organisms.

Microevolution could be resistance to disease (ex. Covid, the Black Plague, etc.) or reduction in genes for additive behavior and Macroevolution being blends of hominid lineages leading to modern humans

A population has two alleles at a locus Y, y. What are p and q for a population with 12 homozygous recessive individuals (yy), 8 homozygous dominant individuals (YY), and 4 heterozygous individuals (Yy)?

Y = p; so (8 x 2) + (4) = 20/48 = p = 0.416
y = q; so (12 x 2) + 4 = 28/48 = q = 0.583

Explain the Hardy-Weinberg principle of equilibrium theory.

The Hardy-Weinberg principle of equilibrium is a null theoretical starting point and is used to describe the genetic makeup of a population. The theory states that a population’s allele and genotype frequencies are inherently stable: unless some kind of evolutionary force is acting upon the population, generation after generation of the population would carry the same genes, and individuals would, as a whole, look essentially the same.

Describe a situation in which a population would undergo the bottleneck effect and explain what impact that would have on the population’s gene pool.

A hurricane kills a large percentage of a population of sand-dwelling crustaceans—only a few individuals survive. The alleles carried by those surviving individuals would represent the entire population’s gene pool. If those surviving individuals are not representative of the original population, the post-hurricane gene pool will differ from the original gene pool.

What is used to determine systematic phylogeny?
a. mutations
b. DNA
c. evolutionary relatedness
d. organisms on earth

c. evolutionary relatedness

What do scientists in the field of systematics accomplish?
a. discover new fossil sites
b. organize and classify organisms
c. name new species
d. communicate among field biologists

b. organize and classify organisms

Which statement about the taxonomic classification system is correct?
a. There are more domains than kingdoms.
b. Kingdoms are the top category of classification.
c. Classes are divisions of orders.
d. Subspecies are the most specific category of classification.

d. Subspecies are the most specific category of classification

On a phylogenetic tree, which term refers to lineages that diverged from the same node on the tree?
a. sister taxa
b. basal taxa
c. rooted taxa
d. dichotomous taxa

a. sister taxa

Which statement about analogous characters is correct?
a. They occur only as errors.
b. They are synonymous with homologous traits.
c. They are derived by similar environmental constraints.
d. They are a form of mutation

c. They are derived by similar environmental constraints

What do scientists use to apply cladistics?
a. homologous traits
b. homoplasies
c. analogous traits
d. monophyletic groups

b. homoplasies

What is true about organisms that are a part of the same clade?
a. They all share the same basic characteristics.
b. They evolved from a shared ancestor.
c. They usually fall into the same classification taxa.
d. They have identical phylogenies.

b. They evolved from a shared ancestor.

The transfer of genes by a mechanism not involving meiosis / sexual reproduction is called:
a. vertical gene transfer
b. web of life
c. horizontal gene transfer
d. gene fusion

c. horizontal gene transfer

What does the root/base of the classic systematic phylogenetic tree represent?
a. single common ancestor
b. pool of ancestral organisms
c. new species
d. old species

a. single common ancestor

How does a systematic phylogenetic tree relate to character/trait (synapomorphies)? to the passing of time?

The systematic phylogenetic tree shows the order in which evolutionary events took place and in what order certain characteristics and organisms evolved in relation to others. It does not relate to time unless that data is specifically added.

Some organisms that appear very closely related on a phylogenetic tree may not actually be closely related. Why is this?

In most cases, organisms that appear closely related actually are; however, there are cases where organisms evolved through convergence and appear closely related but are not. Remember all trees are incomplete and are a diagram utilized to support a hypothesis.

List the major divisions or different levels of the taxonomic classification system.

domain, kingdom, phylum, class, order, family, genus, species

Dolphins (mammals) and bony fish have similar body shapes. Is this feature more likely a homologous or analogous trait?

Dolphins are mammals and fish are not, which means that their evolutionary paths (phylogenies) are quite separate. Dolphins probably adapted to have a similar body plan after returning to an aquatic lifestyle, and, therefore, this trait is probably analogous.

Why is it so important for scientists to distinguish between homologous and analogous characteristics before building phylogenetic trees?

Systematic phylogenetic trees are based on evolutionary connections. If an analogous similarity were used on a tree, this would be erroneous and, furthermore, would cause the subsequent branches to be inaccurate.

Which Hardy Weinberg condition is being violated in this example: some moths on a tree on a tree are easier to see due to their lighter color and therefore are eaten by predators more often.

a) large population size

b) no mutation

c) random mating occuring

d) no gene flow)

e) no selection

e) no selection

Which Hardy-Weinberg condition is violated in this example: Male elephant seals show aggression toward other males, resulting in dominant males mating with several females and other males mating with few or no females.

a) large population

b) no mutation

c) no gene flow

d) random mating occuring

e) no selection

d) random mating occuring

Which Hardy-Weinberg condition is violated in this example: Due to global warming, a river has dried up, allowing two different rabbits that were previously isolated to make with another.

a) large population

b) no mutation

c) no gene flow

e) no selection

b) no gene flow

A reduction in habitat has greatly depleted the greater prairie chicken population and, as a result, their genetic diversity. Which of the following occurred to the population?

a) founder effect

b) mutation

c) natural selection

d) gene flow

e) genetic bottleneck

e) genetic bottleneck

Indicate what type of selection is occuring in this example: Due to less snowfall in an area, white mice are predated on more than are intermediate or dark colored mice.

a) directional selection

b) disruptive selection

c) stabilizing selection

a) directional selection

Indicate what type of selection is occuring in this example: During a drought, it was discovered that finches with large beaks and those with small beaks were more due to the food sources available during the drought.

a) directional selection

b) disruptive selection

c) stabilizing selection

b) disruptive selection

Cystic fibrosis, a recessive genetic disease, occurs in one per 2,500 births among Nothern Europeans. Assuming random mating, what is the frequency of carriers?

a) 1/2,500, or about 0.04&

b) 1/50, or about 2%

c)1/25, or about 4%

d)The frequency cannot be calculated because selection violated Hardy-Weinberg assumptions

c)1/25, or about 4%

The frequency of the sickle cell-allele is as high as 15% due to heterozygous advantage for increased resistance for malaria. If modern technology were to completely eradicate malaria but not alleviate sickle cell disease, what would be expected to happen to sickle cell allele frequency in subsequent generations?

a) remain near 15&

b) gradually drop to toward zero

c) drop slightly, then restabilize

d) rise slightly, then restabilize

b) gradually drop to toward zero