BIOS 1107 Module 1: Evolution IKE & TICA

True or false: according to Platt (1964), the purpose of designing and performing an experiment is to prove a hypothesis.

false

What group in this experiment best fits the purpose of a negative control

students who studied once for 5 min

What is/are the independent variable(s) in this figure?

method of study

What hypotheses should we reject based upon the results of Karpicke and Blunt's study? (What hypotheses does this study provide evidence against?)

Repeated study is the most effective study method for long-term learning, concept mapping is a better study method for inference test questions, students can reliably gauge their own learning

Which of the following is/are a general requirement or characteristic for life on earth

requires energy source, has genetic information, and individuals change over time

what are the three domains of life

bacteria, archaea, eukaryotes

which of these factors is/are required for biological evolution to occur

genetic variation in the population

what did Darwin propose in his theory of evolution

species evolve by natural selection and currentlyexistingspeciesshareacommonancestor

How does a scientific theory differ from a scientific hypothesis

a theory is an overall explanation for a major phenomenon or observation and includes hypotheses; hypotheses treat more specific observations

Which of the following is true of evolution?

Only populations can evolve; individual organisms cannot evolve; Natural selection does not always result in an ideal fit between an organism and its environment

Which of the following is not alive?

a molecule of DNA, a virus, and a robot which can build nearly identical replicates of itself

Some insects are now resistant to all commonly used pesticides. Which is the better explanation for this observation?

some insects carried alleles for resistance to the pesticide before contact with the pesticides and their numbers increased after pesticides became common

what will happen to a population of snakes if the small mice they normally eat are no longer available and all that is left are larger rats that are more difficult to swallow

The individual snakes that already have slightly wider jaws that allow them to eat rats would be more likely to survive and reproduce.

Mammals in Australia are called marsupials, and diverged from the placental mammals very early in mammalian evolution. Australian sugar gliders and North American flying squirrels (see picture) have membranes of skin between their forelimbs and hindlimbs that allow them to glide between tree branches. Are their membranes homologous or analogous?

analogous

What vertebrate fossils would be found in the period 370-380 million years ago?

transitional species, lobe-finned fish, other fish

How does natural selection explain how bacterial populations evolve resistance to antibiotics

rare, resistant mutant bacteria in the population survive antibiotic treatment

what conditions lead to evolution by natural selection

competition for limiting resources and heritable variation in population

which of the following statements is/are accurate

natural selection works on variation already present in a population

which statement describes the canary with the greatest biological fitness

canary that lives to be 2 years old and has four offspring, all of which survive to reproduce themselves

selection that results in a shift in the population toward one extreme phenotype is best described as

directional

selection that results in elimination of extreme phenotypes and enrichment for the average phenotype in the population is best described as

stabilizing

in the case of rock pocket mice, what is the selective agent

owls

what type of selection would you expect at site A

directional

at site A, why does the dark fur trait persist and increase in frequency over time

individuals with dark fur are more likely to have surviving offspring

what color variant would have the highest fitness at site B

either dark or light, but not intermediate

which of these is the smallest unit that natural selection can change

a population's allele frequency

which of these is the smallest unit upon which natural selection directly acts on

an individual's phenotype

biological fitness is based on

How many surviving offspring an individual has, relative to others in the population

Individuals who have one normal and one sickle cell allele have increased resistance to the malarial parasite, which infects red blood cells. The sickle cell allele is extremely common in parts of the world where malaria is also common, but extremely uncommon in parts of the world where there is little or no malaria. Which of the following best explains this observation?

Balancing selection because neither allele alone has a fitness advantage over the other

Song thrushes, like many birds, hunt by sight. They commonly prey on a species of snail that has many different shell colors. Shell color is genetically controlled. The song thrushes tend to hunt whichever color snail is most common, because it is easiest for the birds to quickly identify this color since it is most common. With high levels of predation on the most common shell color, there are fewer of these snails to reproduce and thus most commonly-hunted color becomes less common. This is an example of

Balancing selection, because no single color allele has a consistent fitness advantage over any other

Which of the following is true of the song thrushes in this case?

The individual song thrushes have adjusted their behavior to hunt the new most-common colored snails; this change does not demonstrate evolution

According to Platt, the author of "Strong Inference," scientists should design experiments in order to

disprove as many hypotheses as possible

what is the dependent variable in this experiment

the percent correct answers

If the hypothesis being tested is that peer discussion helps students learn, which of the following would be the best negative control?

a group of students given Q2 after Q1, without any peer discussion.

What hypothesis can we reject based on the results of Smith et al.?

students cannot learn from each other

Which of the following is/are NOT a general requirement or characteristic for cellular life on Earth?

contains a nucleus

What did Darwin propose in his theory of evolution?

Currently existing species all descended from a common ancestor and Natural selection explains the evolution and adaptation of species

which of these factors are required for biological evolution by natural selection to occur

genetic variation in the population and competition among individuals in the population for limited resources

which of these has these individuals has the greatest relative fitness in evolutionary terms

A female squirrel that lived 4 years. She had 3 progeny each in years 3 and 4. All survived to reproduce.

Myxoma virus infects only rabbits. It spreads by direct contact with infected rabbits, or via fleas or mosquitos that have bitten infected rabbits. Which of these myxoma virus strains have greater evolutionary fitness?

a strain that reproduces slowly, producing fewer progeny over a longer time period, and does not kill the host.

Suppose that we have a scrub desert with light colored sand, and numerous patches of dark-colored rocks. Mice with two copies of a dark fur color allele are dark-colored and blend well with dark-colored rocks. Mice with two copies of a light color allele are light-colored and blend well with the sand. Mice with one copy of each (heterozygotes) are a brown color that does not blend well with either the sand or the dark-colored rocks. As a result, the brown mice are more susceptible to predators. Which type of selection is most likely to operate in this situation?

disruptive selection

A large portion of the corn crop has been genetically engineered to produce a protein that toxic to corn borers, an insect pest of corn (the protein has no effect on mammals). Which of the following conditions would be necessary for the corn borer to evolve resistance to the toxic protein?

the corn borer must have heritable variation in resistance to the toxin

Ground finches on an island in the Galapagos suffered a population loss during the 1977 drought. Before the drought, finches had an average beak depth of 9.4 mm and ate seeds of various sizes. The drought reduced the number of small seeds on the island, leaving only larger seeds. After the drought few birds survived, and their average beak depth was 10.2 mm (see figure). The average beak size increased during this drought because

larger-beaked birds were already in the population, and they survived better during the drought.

Ground finches on an island in the Galapagos suffered a population loss during the 1977 drought. Before the drought, finches had an average beak depth of 9.4 mm and ate seeds of various sizes. The drought reduced the number of small seeds on the island, leaving only larger seeds. After the drought few birds survived, and their average beak depth was 10.2 mm (see figure). The average beak size increased during this drought, indicating that _________ selection had occurred.

directional

There are multiple HLA genes in the human genome, and there are hundreds to thousands of different HLA alleles present in the population for each different HLA gene. Each allele encodes a slightly different version of the HLA protein, and these slight differences mean that each different HLA protein has a slightly different ability to detect different pathogens. Most individuals have different alleles at each of their HLA genes, resulting in ability to dect more types of pathogens.

These observations are best explained by:

Balancing selection because no single allele has a consistent fitness advantage over any other allele

how did these antibiotic resistant bacteria arise

The mutations allowing survival in the presence of antibiotic were already present at low frequency in the starting population

Often when treating a bacterial infection in a patient with antibiotics, there are some rare individual bacteria in the population which are resistant to the antibiotic in being used. However, when antibiotics are taken properly, these bacteria do not have the opportunity to become more common because the immune system kills these resistant bacteria while the antibiotic kills the antibiotic-sensitive bacteria.

Considering the results of the antibiotic resistance"mega" plate experiment, which approach do you think would be MOST effective for treating a bacterial infection in an immuno-compromised individual (someone whose immune system does not function well and thus will not clear the resistant bacteria as effectively)?

treating with a cocktail of multiple antibiotics at the same time

Which of the following is a key difference between natural selection and genetic drift?

Drift generates a random shift in phenotypic frequencies, while selection generates a shift toward the environmentally favored phenotype.

Which mechanism(s) of evolution always increase(s) fitness and leads to adaptation?

natural selection

Acting alone, which mechanism of evolution has the least impact on allele frequencies?

mutation

Which mechanism of evolution results from interbreeding after migration of one population into an area containing another population?

gene flow

evolution results in a better match of an organism and the environment

sometimes

A researcher wants to know if a single population of fruit flies on a Pacific island is actually composed of two or more subpopulations that mate preferentially within their subgroup rather than randomly mating. To detect such assortative mating, she could

Determine if the population is in Hardy-Weinberg equilibrium or not.

An opossum population has a gene with two alleles, A1 and A2. If 80% of the gametes produced in the population contain the A1 allele (the A1 allele frequency is 0.8) and the population is in Hardy-Weinberg Equilibrium, what proportion of the offspring flies will carry both A1 and A2?

0.32

If you then sample a second opossum population that has the same starting allele frequency, and find that the proportion of A1 homozygotes (A1A1 individuals) is 90%, you would likely say that

There is strong evidence that evolution is occurring in the second opossum population

If evolution were noticeably occurring in one of these opossum populations, its causes include

Mutation, natural selection, and genetic drift

How can you tell if a population is in HWE?

The population is in HWE if the genotype frequencies are p^2, 2pq, and q^2

Imagine two separate populations of mice at sites A and D below. What would be the effect of gene flow between these two populations?

Decreased overall adaptation in each population due to increased genetic diversity

Blind Mexican cavefish (Astyanax mexicanus) live in caves and do not have eyes as adults (though they do form eyes during development). The cave fish diverged from a surface-dwelling population which does have eyes, after small numbers of random surface-dwellling individuals became trapped in cave streams. The cave fish have extremely low genetic diversity compared to their surface-dwelling close relatives (pictured below). This observation is best explained by:

genetic drift due to founder effect

which of the following statements about gene flow is/are true?

Gene flow can increase genetic diversity in a population, Gene flow can prevent a population from adapting to its local environment, Gene flow can make two populations more similar to each other

Inbreeding can cause increased homozygosity (more homozygous individuals) in the population. Which of the following would also likely result in increase homozygosity?

positive assortative mating

If 9% of a human Mediterranean population is born with a severe form of sickle-cell anemia, with homozygous genotype ss, what approximate percentage of the population will be heterozygous Ss for the sickle-cell gene and therefore resistant to malaria? Assume Hardy-Weinberg proportions to answer this question.

42%

In reality, would you expect a human population that has sickle cell allele and lives in the presence of malaria to be in Hardy Weinberg Equilibrium for the sickle cell trait?

no

If you observed that a human population living in the presence of malaria was NOT in HWE for sickle cell trait, this population COULD be experiencing:

genetic drift, gene flow, natural selection, non-random mating, or mutation

Why does HW assume an extremely large population size?

large population minimizes the likelihood of genetic drift

Speciation that can occur in a sexually reproducing species split into two populations by a geographic barrier to gene flow is best described as

allopatric

You examine fossils of extinct trilobites. All the specimens look identical and were collected from the same fossil bed. You can assert that they are members of the same

morphological species

hybrids occur

when two species interbreed

when a male donkey mates with a female horse, the hybrid offspring is an infertile mule. This reproductive barrier is

post zygotic

The antennae of male moths can only detect sex pheromones released by a female of his same species. This reproductive barrier is:

pre zygotic

speciation always occurs in allopatry because there is no mechanism for two species to evolve in sympatry

false

maggots experience selection pressure to

eat apple because of lower parasitism rates

which information is relevant to the biological species definition

there is a 4-6% hybridization rate between hawthorn and apple maggot flies

according to the biological species concept, are hawthorn and apple maggot flies separate species

no

which of the following is a limitation of the biological species concept

it cannot be applied to prokaryotes, it cannot accurately distinguish between species that are capable of interbreeding (for example, in the captivity) but never do in the wild, it cannot be applied to extinct species

which information is relevant to the ecological species definition

hawthorn and apple maggot flies strongly prefer to mate and lay fertilized eggs in hawthorns and apples respectively

According to the ecological species concept, are hawthorn and apple maggot flies separate species?

yes

Which information is relevant to the morphological species definition?

Hawthorn and apple maggot flies are physically indistinguishable.

According to the morphological species concept, are hawthorn and apple maggot flies separate species?

no

Speciation in Rhagoletis maggot flies is

sympatric

What reproductive barrier, or barriers, limits interbreeding between hawthorn and apple maggot flies?

habitat isolation and temporal isolation

Hawthorn and apple maggot fly populations are subject to:

prezygotic reproductive barriers

Which of the following best describes speciation between hawthorn and apple maggot flies?

hawthorn and apple maggot flies are likely to become separate species

What type of natural selection will increase the reproductive barriers between apple and hawthorn maggot flies?

disruptive

Which of the following is likely to lead to speciation between hawthorne and apple maggot flies?

decreased gene flow between the two fly populations

Global climate change is altering the flowering and fruiting timing of plants around the world. If apple and hawthorn plants began flowering and fruiting at the same time, would this slow down or speed up the speciation between apple maggot flies and hawthorn maggot flies?

slow down

The above image shows the generally accepted phylogenetic tree of life. Archaea and Bacteria are both prokaryotic forms of life. Is the term "prokaryote" monophyletic?

no, it is not monophyletic

based on the tree below, which of the following is true?

giraffe is more closely related to a hippo than a horse.

Variation for traits within a population is a prerequisite for evolution because

selective agents act on traits, differentially removing or retaining individuals with certain trait values.

Some dog breeds exhibit high frequencies of a number of genetic disorders including hip dysplasia, epilepsy, and immune-system dysfunction. These effects can be best explained by:

inbreeding

Which of the following is NOT an example of non-random mating?

A coyote mates with the available female it encounters as it travels across the coyote-population range

Which evolutionary mechanism can best explain why light morphs are more abundant than dark morphs in Population A in the presence of bird predators?

natural selection

You survey Population A again several years later to find one individual of this damselfly species with a metallic blue color. Which evolutionary mechanism is most likely to have been responsible for this development?

mutation

An earthquake wipes out a mainland population of a small flowering herb with highly variable flower shapes. A small remnant contains the seven remaining plants in the population. The most likely outcome for the population as a result of this is

a reduction in floral trait variation

The evolutionary processes that influence population evolution from one generation to the next include

Alleles arriving in a population in a new migrant, Creation of new alleles in a population, Random loss of genetic diversity in a population

After genetic drift has occurred, indicate all of the following that are most likely true:

The population is less genetically diverse than in the previous generation, The allele frequencies have changed from the previous generation.

The effect of mutation on a population

increases genetic diversity

Gene flow is a relevant evolutionary process when an anolis lizard with a green dewlap

rafts on driftwood across to an island with lizards with yellow dewlaps.

If 36 out of 100 individuals show the recessive phenotype for a particular trait, AND the population is in Hardy-Weinberg Equilibrium, what is the predicted genotype frequency of the heterozygote?

0.48

Suppose that rabbit fur color is controlled by one gene with two alleles with incomplete dominance. BB individuals are black, Bb individuals are gray, and bb individuals are white. A population has 15 black rabbits, 30 gray rabbits, and 55 white rabbits. Is this population evolving at the fur color locus?

yes, the population is evolving