Biology exam 2

A population of snails exhibit assortative mating: individuals mate according to the direction of their shell's spiral. 99.99% of brown garden snails have shells that turn clockwise. In 2016, scientists used a twitter hashtag to find a mate for Jeremy, a brown garden snail that was a "lefty" mutant. Since Jeremy was unable to find a mate on his own, what direction did his shell turn?

counter-clockwise

Biological sex is always determined by sex chromosomes (X and Y).

False

Over many centuries, average temperatures in a region have become warmer. As a consequence, small sized rabbits have had greater survival, as they are less prone to overheating, resulting a decrease in the mean body size of the population. This evolutionary process is known as...

directional selection.

Fossil evidence supports the idea that feathers originally evolved for the purpose of flight.

false

Which form of evolutionary change is responsible for the development of pesticide (DDT) resistance in insects that damage crops?

natural selection

Which of the following microevolutionary processes are the two main contributors to divergence between populations that have been reproductively isolated?

natural selection Drift (founder effect or bottleneck) mutation

two bower birds 1.builds stick tower and decorates it with charcoal to attract females of his species 2.builds a "channel" and decorates it with blue objects to attract females of his species

behavioral isolation

The global distribution of flightless birds (Ratites) illustrates which of the following types of evidence for evolution?

biogeography

Consider a large population of organisms with a gene having two alleles, B and b. In a given environment, the relative fitnesses of the three genotypes are as follows: BB homozygotes = 0.8; bb homozygotes = 0.2; Bb heterozygotes = 1.0. After a number of generations,

both B and b alleles should remain common in the gene pool as long as the environment hasn't changed.

Microevolution

changes in the genetic makeup of a population over time

The molecular clock relies on what to determine the age of species?

constant mutation rates

While canoeing in the Boundary Waters Canoe Area, you see a bird pass in front of your canoe. Being the ardent birder you are, you immediately refer to the bird field guide that never leaves your side. The field guide distinguishes among the different species based on morphological characteristics, like feather color. In using the field guide to determine what species you have seen, what type of classification system are you using?

phenetic

The inclusion of birds in Class Reptilia due to their genetic similarity with reptiles is an example of a shift from

phenetic to phylogenetic classification

Inbreeding exposes some mutations that otherwise would likely never be expressed. What kinds of mutations would they be?

rare and recessive

Mutations in HOX genes are often responsible for major evolutionary changes because they...

regulate the development of an organism.

Select the species whose origins would most likely need to be determined by a molecular clock.

slug b/c As a land dwelling organism without any hard body parts, slugs are more likely to decompose than fossilize. Without fossils, a molecular clock can help determine origins.

Allopatric speciation

speciation with geographic isolation

A population of lacewings is observed to breed during the spring. A mutation arises in a population of lacewings, however, that causes those with the mutation to delay breeding until late summer. Over several generations, the population diverges into two discrete breeding populations, spring and summer, that no longer breed with one another. In the scenario above, the two new populations have become two separate species. The speciation process best describing what occurred is...

sympatric speciation with pre-zygotic reproductive isolation.

two fruit flies: 1. breeds early in the morning 2.breeds in the afternoon

temporal isolation

Which of the following is the best definition of microevolution?

the change in the genetic composition of a population over time

Law of faunal succession

the same fossil assemblages are found in rock layers of the same age

gene pool

total aggregate of genes in a population at one time

Each human has, on average, one or two mutated alleles that were not present in either parent.

true

Sex and reproduction don't always occur at the same time.

True

Population

localized. group of individuals of the same species

In haplodiploid organisms...

males develop from unfertilized eggs and females develop from fertilized eggs.

male genitals of different damselfly are shaped very differently... .. they only fit with the female genitalia of the same damselfly species

mechanical isolation

hat is the ultimate source of variation in a trait?

mutation

Which evolutionary forces are nonadaptive?

mutation, bottlenecks, founder effect, genetic drift

Under the conditions of Hardy-Weinberg equilibrium for a gene with two alleles in a population of organisms, if the relative frequency of recessive allele "a" is 0.25, what would be the expected relative frequency of heterozygous individuals (Aa)?

0.375

In a population of 500 moths, 150 are genotype BB, 250 are genotype Bb, and 100 are genotype bb. The relative frequency of the dominant (B) allele in this population is...

0.55

thoughts contributed to development of species.

1.Linneaus A:species do not change. they reflect gods divine order. 2.Aristotle A:life strives to move from inanimate matter up through the lower life forms of perfection in the human form. 3.Lamarck A:species evolve by inheriting acquired traits

Match each type of male competition with the time it occurs. 1.Infanticide 2.Sperm competition 3.Combat

1. after mating 2. during mating 3. before mating

Natural selection is the same process as artificial selection, except it does not involve human intervention. For each statement about dog breeding, match it with one of the four requirements for evolution by natural selection.

1."I'm only going to breed two puppies, I'm neutering the rest." A:there are more individuals born than can survive or reproduce 2."I'm going to breed the biggest dogs." A:individuals with certain traits are more likely to survive and reproduce 3."The dogs in the litter are not all the same size." A:there is variation in a trait 4."Bigger mother dogs give birth to bigger puppies." A:the trait is heritable

Select all true statements regarding HOX genes.

1.HOX genes are found in all animals. 2.HOX genes control the development of an organism.

influence they had on Darwin's thinking.

1.Lyell A: darwin applied his idea about geology (uniformitatirism) to biology 2.wallace A:he independently thought of the theory of natural selection and prompted Darwin to final publish his theory. 3.malthus A:his ideas about the relative growth rate of human populations and the food supply contributed to Darwins thoughts on survival.

In the wild, to bird duck species occasionally mate, but do not produce offspring. However, in the lab, their gametes can be joined in fertilization to make viable and fertile offspring. Which of the following types of reproductive isolation would happen between mating and fertilization?

1.Mechanical isolation 2.Gametic isolation

Select all the statements that are TRUE

1.Most multicellular organisms are sexual. 2.Sexual reproduction evolves to benefit the individual

Which traits signal to the female that the male has genes that will make her offspring more likely to survive?

1.Strength 2.Nutritional gifts

observation Darwin made during his voyage on the HMS Beagle?

1.There were animals and fossils that were found on some continents and not others. 2.Finches in the Galapagos Islands had specialized beaks for different diets. did not: 4.Different finch species in the Galapagos Islands had different survival rates.

Select all the true statements regarding the action of natural selection. You must choose all correct answers.

1.Traits can change function throughout time. 2.Selection acts on whatever traits are available.

The human tailbone is...

1.a vestigial trait. 2.homologous to a dog's tail. 3.evidence of common ancestry with other animals having tails.

Match each macroevolutionary pattern with the microevolutionary process it reflects.

1.directional selection A:large scale adaptions 2.island speciation A:worldwide biogeography 3.stabilizing selection A:consistently small size of fossil and living bacteria

The argument of irreducible complexity has been rejected by biologists because...

1.it assumes that the function of a structure cannot change over time. 2.it assumes simpler forms of complex structures are not functional. 3.simulation experiments have shown that irreducibly complex structures can arise by the process of evolution by natural selection.

Choose the correct limitation on male and female fitness: 1. male fitness 2. female fitness

1.limited by the number of mating opportunities 2.limited by ability to convert resources to offspring

Match the sexual process to the evolutionary benefit it confers in bacteria. Repairs damaged DNA: transformation Spreads genes to other individuals conjugation

1.transformation 2.conjugation

The fossil record allows us to build a rough timeline of life on Earth. We can determine the age of fossils using several techniques. Match the technique to its appropriate use or description. 1.Absolute relative dating 2.Relative dating 3.Slow decaying isotopes 4.Fast decaying isotopes

1.uses isotope decay rates to estimate age of fossils 2.uses the law of superposition to estimate the age of fossils. 3.used to estimate the age of older fossils 4.used to estimate the age of younger fossils

An organism cannot change its sex.

False

Which cost of sex makes it such an evolutionary puzzle?

50% loss of you genes each generation

What is adaptive radiation?

A rapid series of speciation events where populations specialize on different ecological niches (roles).

Consider the population in the image. Red and blue individuals are equally able to survive and reproduce. After a single generation, what is most likely to be the effect of genetic drift?

Blue individuals will go extinct

Which of the following is an example of sex without reproduction?

Conjugation

Individuals indigenous to the Andes (high-altitude mountains) have adapted to their low-oxygen environment by increasing respiration efficiency in their brain (a high-energy organ). This is an example what pattern of selection?

Directional selection

Why is it hard for selection to remove recessive alleles from thepopulation, even if they reduce an individual's fitness?

Even though recessive alleles can be detrimental to an individual's fitness, they don't disappear. This is because natural selection is only influenced by the phenotype, and not the genotype. This means that people with the genotype Rr make the recessive allele persist through gene pools because they are "protected" by the R allele, ensuring that the r allele doesn't disappear. Another reason is rare recessive alleles (example being cystic fibrosis), these are harmful alleles that become rare due to homozygous recessive individuals rarely surviving to produce offspring. (However, these often are passed down and hidden, but eventually resurface in the population under the right conditions).

Southern yellow-billed hornbills live in the Kalahari Desert, whichhas low rainfall and high summertime temperatures. Yellow-billedhornbills live in breeding pairs or small family groups. When theybegin their courtship, the male feeds the female for up to a month bybringing her small bits of food. Females are attracted to males withrichly pigmented bills and less likely to choose a male with dull bills.However, males with richer pigmentation have trouble regulatingtheir body temperature in warmer weather and often don't surviveto adulthood. On the other hand, females become more insistent onbrighter pigmentation in hotter climates. As the effects of climatechange increase, what pattern of natural selection would we expectwith respect to the amount of pigment in males?

Females will always prefer bright bills, selecting against dull bills. But, with increasing temperatures, having bright bills will be cause males to die, leading greater selection against having too bright of bills. This lead to stabilizing selection.

Contrast how Lamarck vs. Darwin would explain the evolutionarychange in horses in relation to their transition from forest tograssland habitats?

Lamarck would say that because the horses had to chew the tougher grass and run from predators, they would acquire traits that make them bigger, and faster because they are using these traits constantly. On the other hand, Darwin would describe this as a result of natural selection, where the bigger, faster horses were more fit to reproduce, and ended up passing those traits to the following generations.

The biological species concept emphasizes all of the following EXCEPT:

Members of the same species must look alike emphasizes: 1.Individuals of the same species can and do interbreed. 2.Individuals of different species do not interbreed. 3.Populations of the same species share identical alleles but do not necessarily have identical allele frequencies.

Consider the following hypothetical species: Males and females look nearly identical and have brain chemistry that causes affection. Young offspring survive better when they are cared for by two adults. What trait is this species most likely to h

Monogamy

Which is not an example of a trait changing function over time?

Octopus eye

The "biological species concept" defines species as a group of organisms that are:

Only capable of breeding successfully with one another.

What is the difference between the phenetic and phylogenetic approaches to taxonomy?

Phenetic is based on similarities and phylogenetic is based on evolutionary relationships.

Fingered Poison Frogs are endemic to Trinidad. Females depositsmall clutches of eggs in terrestrial nests. After hatching in July, oneof the parents transport the tadpoles to a small water body, wherethey complete their development to metamorphosis. Suppose thatdue to changing climate conditions small bodies of water are onlyreadily available during certain months of the year. Fingered PoisonFrogs in southern Trinidad begin to only produce offspring duringthe spring months (April and May) and Fingered Poison Frogs inNorthern Trinidad only produce offspring during the fall (September- October). What type of pattern of natural selection would weexpect to see Trinidad's Fingered Poison Frogs population withrespect to time of reproduction?

Reproduction time, 2: Diversifying Selection [synonymous with Disruptive selection], 3: Since it is diversifying selection, I expect that the time they produce their offspring would be either in the April and may months and theSeptember to October months. Otherwise they wouldn't be able to stay alive or produce offspring because of the climate change

What is the biological difference between "males" and "females"?

Size of gametes

Red-cockaded woodpeckers live in mature, open pine forests with littleunderstory. One aspect of managing this endangered species is trying toconnect isolated populations with corridors of appropriate habitat. Can youthink of ​two​ evolutionary reasons why connecting small, isolatedpopulations is important for the conservation of a species? (​Hint​: bothreasons have to do with genetic diversity).

Small populations are at risk of extinction because of genetic drift. Genetic drift may cause harmful allele frequencies to increase, putting the population at risk. In addition, small, isolated populations probably face problems within breeding, increasing the risk that harmful alleles will be transmitted to the next generations (founder effect). This is why connecting small, isolated populations helps with conservation -- these risks are avoided. Increasing the population will also prevent chance events like the founder effect and genetic drift from altering the gene pool of the species in a negative way overall the connection of small isolated populations has a generally positive effect on the species.

Sympatric speciation

Speciation without geographic population.

This population is not in Hardy-Weinberg equilibrium. What are theobserved genotype frequencies for this population and what is theHW equilibrium expectation? (Show your work).

The [observed] genotype frequencies are: FF - 0.3 (150/500), Ff - 0.6 (300/500), ff - 0.1 (50/500)The Hardy-Weinberg equilibrium expectation is: FF - 0.36(0.6^2), Ff - 0.48 (2*0.6*0.4), ff - 0.16 (0.4^2)

What do nondisjunctions have to do with speciation?

The can results in the formation of new polypoid species.

Which of the following is most consistent with Darwin's view of the nature of evolutionary change?

The evolution of structures such as the eye was a slow process requiring numerous intermediate steps.

Natural selection is not the only force that causes populations to evolve.What four other forces result in evolution and how does each one affectgenetic diversity in a population?

The four other forces are gene flow, mutation, non random mating (inbreeding and assortative mating) and chance events in small populations (founder effect and genetic drift). Gene flow is the gene transfer from one population to another. Mutation is a mistake that happens during the DNA replication process which is an unequal crossover. Non-random mating which includes inbreeding in which each family suffers the founder effect and assortative mating which is similar phenotypes mate with each other. The founder effect is a group of individuals that move to an area with their own species. Genetic drift is different genotypes in a small population.​ The chance events that cause changes in allele frequency. usually decreases genetic diversity, only a real issue in smaller populations.

What is the biological definition of sex?

The fusion of genes from more than one individual.

Which of the following is TRUE?

The oldest organisms in the fossil record are single-celled organisms

What does the principle of superposition tell us about the evolutionof horse size?

The principle of superposition gives us the relative order of changes in the evolution of horse size. For example, because the Eohippus is at the bottom of the rock in the diagram, we know that it is the oldest compared to all of the others and we can see the order of size change by going up in the layers.

Fantail Warblers are birds that live in subtropical regions of Africa.An ectopic parasitic louse is a specialist parasite of Fantail Warblers.However, populations of this parasitic lice are declining due toclimate change. Previously the birds with thicker feathers (whichrequired more energy to produce) were more resistant to theparasitic weaver. As the effects of climate change increase, what typeof pattern of natural selection would we expect to see in the fantailwarbler population with respect to feather thickness?

Trait under selection is thick feathers, 2: Directional selection, 3: I expect the frequency of thick feathers to decrease because they are no longer necessary due to the climate change and they take more energy to produce.

A single organism can produce both male (sperm) and female (eggs) gametes.

True

Consider a diploid population of protists pictured in the image below. Their color is produced a purple pigment controlled by a single gene (p) with two alleles (p+ and p-). Choose the answer for each question.

What is the total number of individuals? A: 10 What is the total number of alleles in the population? A:20 What is the number of p+ alleles? A:8 What is the gene frequency of p+ alleles in this gene pool? A:0.4

.Two populations of the same species of grass, one small and one large. Bothpopulations are shown to vary in their resistance to a common fungaldisease. A drought drastically reduced both populations of grass to just afew individuals. The following growing season, when the populations haverecovered, the small population is completely wiped out by the fungalpathogen, while the large population shows roughly the same level ofresistance. What happened to the alleles that conferred resistance in thesmall population and why didn't this happen in the large population? (​Hint:think genetic drift).

When something as significant as a drought occurs, it produces a "bottleneck effect" [an extreme type of genetic drift] where only a few individuals are left. Those alleles then are the founding alleles for the new population. It is likely that the small population was only left with alleles that were non-resistant to the fungus pathogen whereas the large population was left with mostly alleles that could withstand the pathogen.

Compare the wings of robins (birds) and fruit bats (mammals). As structures of flight, robin wings and fruit bat wings are considered ____[1]_____ structures. The humerus (upper wing bone) in birds and the humerus bone in fruit bats are considered _____[2]______ structures.

[1] analogous; [2] homologous.

The video lectures discuss the example of how alleles that cause sickle cell anemia can also confer resistance to malaria. This example illustrates how...

a particular genotype can have different relative fitnesses in different environments.

An organism's fitness depends on its

ability to survive and reproduce.

Convergent evolution

analogous trait

You observe the follow facts about a population of frogs: More frogs are born than survive to adulthood. Frogs vary in size when they reach reproductive maturity. Larger frogs lay more eggs. Adult size does not correlate with the subsequent size of their offspring. Do you expect this population to evolve by natural selection?

false

Below is an image of a blind cave fish that lives deep in a cave and is never exposed to light. There are similar fish that live in a stream outside the cave, except they have fully formed eyes. How would Lamarck have finished this explanation? Long ago, these fish had eyes. Over many generations . . .

fish did not use their eyes and their eyes became smaller. They passed these smaller eyes on to their offspring.

Uniformitarianism

forces at work today have operated the same way throughout all of earths history

Which of one of the following mechanisms would result in lower genetic diversity within a population?

founder effect

only egg and sperm of the same species are chemically compatible and will undergo fertilization

gametic isolation

migration

gene flow among populations

Hybridization

gene flow among species

Immigration

gene flow into a population of interest

Emigration

gene flow out of a population of interests

You have been studying a small (over the course of your study this population has stayed at about 20 individuals each generation), isolated population of field mice for many generations. You have determined that there is a single locus with two alleles that controls coat color in this species: GG individuals are black, Gg individuals are dark brown, and gg individuals are tan. You have also found that tan individuals are the most obvious to predators and have the lowest relative fitness while the relative fitness of black individuals is the highest. In the current generation you have found that the population consists of only tan individuals. Which evolutionary force is most likely to have produced this recent change?

genetic drift

Which of the following is most consistent with Darwin's view of the nature of evolutionary change?

he evolution of structures such as the eye was a slow process requiring numerous transitional steps.

Common ancestry

homologous trait

A phylogeny can tell all of the following EXCEPT

how two species are reproductively isolated.

Darwin differed from Lamarck in his (Darwin's) proposal that...

inherent variations in the population are more important in evolution than variations acquired during individual lifetimes.

Macroevolution

large-scale genetic change encompassing many populations

Genetic Evidence suggests that feathers evolved . . .

via few mutations of large effect.

Drift has __________ effect on large populations, compared to its effect on small populations.

weaker

Superposition

young players of rock are laid down top of older layers of rock