Evolution Exam

The first organisms recorded in the fossil record were most likely a. anaerobic bacteria b. protocells c. photosynthetic d. filamentous eukaryotes

a. anaerobic bacteria

Natural selection is sometimes described as "survival of the fittest." Which of the following best measures an organism's fitness? a. how many fertile offspring it produces b. its mutation rate c. how strong it is when pitted against others d. how much food it is able to make or obtain

a. how many fertile offspring it produces

Drought conditions in the Galapagos Islands during the 1970s caused a drop in the populations of grasses and other plants that produce small seeds, but was not so drastic in affecting plants that produce large seeds. This had the following effect on the finches of the islands: a. increased the size of beaks b. increased the number of species c. increased the competition form iguanas d. no effect

a. increased the size of beaks

The data here show the frequencies of the two morphs of Biston betularia -- carbonaria, the dark form, and typica, the light spotted form, from 1950 to 2000, when oil was replacing coal as a heating fuel in the country. These data based upon experiments by Michael Majerus were intended to check the validity of earlier experiments of this type done by Kettlewell. Kettlewell's data was questioned because of which reason listed below: a. Kettlewell recovered a higher proportion of the carbonaria when he collected in the clean areas than the polluted ones. b. Kettlewell used lab grown and wild populations of moths mixed together. c. Kettlewell recovered equal proportions of carbonaria in both polluted and clean areas. d. Kettlewell used population sizes that were well below the normal population size in the areas where he ran his experiments.

b. Kettlewell used lab grown and wild populations of moths mixed together.

The Cambrian explosion describes a time when a. The fossil record indicates that dinosaurs became extinct. b. Many of the body plans for modern organisms appeared in the fossil record, including the ancestor of vertebrates. c. Anomalocarus, the ancestor of all mammals, appeared in the fossil record. d. The fossil record suggests that fish began to walk on land.

b. Many of the body plans for modern organisms appeared in the fossil record, including the ancestor of vertebrates.

Which describes the relationship between mutation and natural selection? a. Mutation occurs randomly as a result of natural selection. b. Mutation creates variation within a population and increases the chance of survival of a population in a changing environment. c. Mutation rate is directionally driven in response to different selection pressures. d. Natural selection occurs in populations that are genetically stable.

b. Mutation creates variation within a population and increases the chance of survival of a population in a changing environment.

Wallace wrote that after a long period of natural selection, "the superior variety would then alone remain, and would have replaced the original species." Which of the following would be a good addition to this statement? a. Thus, in a long line of descent one species replaces another, so that the total number of species does not change over time. b. Of course, this does not rule out that the original species might live on elsewhere, where conditions were different since the beginning. c. It is clear from this that there is a natural tendency for organisms to become more and more nearly perfect, culminating in superior varieties in every lineage from the lowliest protozoa to the modern Europeans. d. Of course this is a mere hypothesis, and because it contradicts currently accepted ideas, it is almost certainly wrong.

b. Of course, this does not rule out that the original species might live on elsewhere, where conditions were different since the beginning.

An emergent property is a. an new trait that has become fixed in the population. b. a situation where the whole is greater than the sum of the individual parts. c. the set of conditions that predispose a species to extinction. d. predictable.

b. a situation where the whole is greater than the sum of the individual parts.

Biologists have found more than 500 species of fruit flies on the various Hawaiian Islands, all apparently descended form a single ancestor species. This example illustrates a. temporal isolation b. adaptive radiation c. sympatric speciation d. polyploidy

b. adaptive radiation

Fossil and genetic evidence strongly support the idea that modern humans a. independently arose from three different ancestral Homo species in Africa and Eurasia b. all derive from a single African lineage that spread from there into other parts of the world starting about 85,000 to 60,000 years ago c. derive from an African lineage but also have genes derived from mixing with several Eurasian descendants of Homo erectus d. derive from Neanderthals that independently evolved the features of modern humans in Europe and Africa

b. all derive from a single African lineage that spread from there into other parts of the world starting about 85,000 to 60,000 years ago

Which of the following could provide the best data for determining the phylogeny of very closely related species? a. the fossil record b. comparison of nucleotide sequences in homologous genes and mitochondrial DNA c. comparison of their embryological development d. their morphological differences and similarities

b. comparison of nucleotide sequences in homologous genes and mitochondrial DNA

The fact that the hand of man, the wing of the bird, the wing of the bat, and the limb of the alligator all have the same bones in the same relative positions a. is the result of the fact that there is only a certain way to make arms, hands, and wings in evolution. b. is explained by common descent of all these organisms from a primitive reptile. c. is due to a parallel evolution of arms and hands in these separate lineages. d. is explained by each appendage having the same function.

b. is explained by common descent of all these organisms from a primitive reptile.

A species is composed of a. group of reproductive females. b. populations that have the potential to interbreed and produce fertile offspring. c. organisms located in the same habitat. d. all males and females in the same geographical range with the same ecological requirements.

b. populations that have the potential to interbreed and produce fertile offspring.

In an area of erratic rainfall, a biologist found that grass plants with alleles for curled leaves reproduced better in dry years, and plants with alleles for flat leaves reproduced better in wet years. This situation would tend to a. cause genetic drift in the grass population b. preserve genetic variation in the grass population c. lead to uniformity in the grass population d. cause gene flow in the grass population

b. preserve genetic variation in the grass population

Ancient photosynthetic prokaryotes were very important in the history of life because they a. were probably the first living things to exist on earth b. produced the oxygen in the atmosphere c. were the first multicellular organisms d. showed that life could evolve around deep-sea vents

b. produced the oxygen in the atmosphere

Deep branch points near the base, or trunk, of an evolutionary tree represent ----, while branch points near the tips of the branches represent ----. a. relatively recent common ancestors; relatively ancient common ancestors b. relatively ancient common ancestors; relatively recent common ancestors c. organisms that share homologous structures; organisms that do not share any homologous structures d. organisms with relatively simple traits; organisms with very complex traits

b. relatively ancient common ancestors; relatively recent common ancestors

Birth weight in humans is the result of a. directional selection b. stabilizing selection c. disruptive selection d. careful family planning and nutrition

b. stabilizing selection

The human fossil record show a. a straight line from descent from Australopithecus to Homo sapiens b. that at several times there were more than one hominid species alive on the earth at the same time c. that most of our knowledge of primitive man has to be inferred from linguistic and cultural studies of remote tribes d. chimpanzees are more closely related to us than to any other hominid species

b. that at several times there were more than one hominid species alive on the earth at the same time

One of the most important clues indicating that A. afarensis (Lucy) walked on two legs is: a. her fossilized remains indicate that Lucy's legs were very long compared to her arms. b. the structure of Lucy's feet are more human-like than chimpanzee-like. c. her heel bones were extremely broad compared to those of apes. d. she possessed the binocular vision necessary for walking upright.

b. the structure of Lucy's feet are more human-like than chimpanzee-like.

There have been six mass extinctions in the last 600 million years. Roughly, how many years does it take to recover the lost biodiveristy after a mass extinction? a. 1,000 b. 10,000 c. 10,000,000 d. 1,000,000,000

c. 10,000,000

Under what circumstances can simple chance affect the frequency of genes in a population? a. When some genes are more suitable for the environment than others. b. When there is a high incidence of radiation causing more mutations. c. When the population is very small thus amplifying the effect of random chance. d. When genes are brought into the population from external sources.

c. When the population is very small thus amplifying the effect of random chance.

Ribozymes a. are the enzymes that engage in protein synthesis. b. are RNA molecules like tRNA and mRNA. c. catalyze chemical reactions but do not contain amino acids. d. are self-replicating primitive genetic elements.

c. catalyze chemical reactions but do not contain amino acids.

Evolution is promoted in a natural population a. if replication of DNA is 100% correct and other types of mutations do not occur b. if mating is always random c. if some genotypes produce phenotypes that are more adaptive than other phenotypes d. if the population is very large in size

c. if some genotypes produce phenotypes that are more adaptive than other phenotypes

Extinction of a species is not uncommon throughout evolutionary time. In fact, a. no organisms live for more than several million years b. an extinction must precede a speciation event. c. it is estimated that over 99% of all species that ever lived are extinct. d. cataclysmic events, such as comets, are entirely responsible for extinctions

c. it is estimated that over 99% of all species that ever lived are extinct.

The fundamental idea in biology that enables us to explain the diverse life forms on earth is that a. all life forms require energy to maintain the structures and drive the processes that keep them alive. b. patterns of embryonic development in organisms that appeared earlier in Earth's history (e.g. fish or frogs) are repeated in the development of more recent organisms (e.g. humans) c. populations undergo descent from one generation to the next, with modification d. a spontaneous process of organic change has occurred over time

c. populations undergo descent from one generation to the next, with modification

Coevolution is a. a special type of evolution that differs from Darwinian evolution. b. a type of evolutionary change that occurs between a population and the physical environment in which that population lives. c. the evolution of two populations of different species in response to selection pressures that individuals from two populations place on each other. d. the evolution of individuals within a population in response to selection pressure from other individuals in the population.

c. the evolution of two populations of different species in response to selection pressures that individuals from two populations place on each other.

The North American Pronghorn far outraces any predators remaining on the North American continent. If maintaining this speed means bearing fewer offspring, which of the following is the most likely to happen given enough time: a. this species will go extinct b. this species will become even faster c. this species will slow down d. this species will split into two new species

c. this species will slow down

Which of the following is an example of allopatric speciation? a. Asian green warblers b. Rhagoletis fruit flies c. Escherichia coli d. Grand Canyon squirrels

d. Grand Canyon squirrels

Of the options listed below, which two Homo species migrated out of Africa beginning about the time noted for the start of their migration? a. H. habilis (2 mya) and H. sapiens (0.2 mya) b. H. erectus (1 mya) and H. neandethalensis (0.4 mya) c. H. neanderthalensis (1 mya) and H. sapiens (0.1 mya) d. H. erectus (2 mya) and H. sapiens (0.1 mya)

d. H. erectus (2 mya) and H. sapiens (0.1 mya)

Which of the following is an example of a postzygotic reproductive barrier? a. One Ceanothus shrub lives on acid soil, another on alkaline soil. b. Mallard and pintail ducks mate at different times of the year. c. Two species of leopard frogs have different mating calls. d. Hybrid offspring of two species of jimsonweeds always die before reproducing.

d. Hybrid offspring of two species of jimsonweeds always die before reproducing.

If you had to choose, where would you rather get infected with a serious bacterial disease? a. In a hospital, where most of the bacteria are probably already weakened by antibiotics int he environment. b. In a livestock barn, where the animals have been treated with antibiotics. c. In a big city, where antibiotics are routinely prescribed by doctors. d. In a remote, sparsely populated area where the bacteria have not been exposed to antibiotic drugs.

d. In a remote, sparsely populated area where the bacteria have not been exposed to antibiotic drugs.

The picture on the right was taken underwater and shows a large number of fish of the same species forming a circle or spiral. Which is the best description of what is going on? a. The fish have organized an intelligent defense against threats from predators by collectively recognizing that many will escape death if there is an attack at this time, due to the opportunity afforded them to escape when the patter of their swimming is interrupted. b. The laws of physics govern all life, and in this case the fish demonstrate this by spontaneously forming a geometric shape conforming closely, if imperfectly due to the variation in their individual bodies, to an ideal form. c. Fish herd together under certain circumstances, such as breeding, and this is just one of the many possible configurations this gathering can appear to show, similar to the fact that clouds can sometimes look like familiar objects to us. d. These fish swim, stick close to their own kind, and imitate what their neighbors do. The result is a swirling circular gathering.

d. These fish swim, stick close to their own kind, and imitate what their neighbors do. The result is a swirling circular gathering.

Which of the following statements would Darwin have disagreed with? a. species change over time b. living species have arisen from earlier life forms c. modern species arose through a process known as "descent with modification" d. descent with modification occurs through inheritance of acquired characteristics

d. descent with modification occurs through inheritance of acquired characteristics

You set your time machine for 3 bya and push the start button. When the dust clears, you look out the window. Which of the following describes what you probably see? a. plants and animals very different from those alive today b. an endless expanse of red-hot molten rock c. a cloud of gas and dust in space d. green scum in the water

d. green scum in the water

Which off the following clues would tell you whether a cell is prokaryotic or eukaryotic? a. the presence of absence of ribosomes b. whether or not the cell carries out cellular metabolism c. the presence or absence of a rigid cell wall d. whether or not the cell is partitioned by internal membranes

d. whether or not the cell is partitioned by internal membranes