Biology [CHAPTER 24] (The Origin of Species) – Flashcards

When gene flow between two populations ceases, the potential for _____ exists. A) Speciation B) Sexual reproduction C) Fusion D) Sexual selection E) Hybridization

Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species that lived side by side in parts of their ranges. However, recent books show them as eastern and western forms of a single species, the yellow-rumped warbler. Apparently, the myrtle warbler and Audubon's warbler _____. A) Successfully interbreed and produce fertile offspring B) Have undergone coevolution C) Are merging to form a single species D) Are almost identical in appearance E) Live in the same areas

Imagine that part of a population of South American finches is blown by a storm onto an island far offshore and manages to survive and reproduce there for a period of 10,000 years. After that period, a climate change results in lower sea levels and the reconnection of the island with the mainland. Members of the formerly isolated island finch population can now interact freely with members of the original mainland population. Which of the following observations would, by itself, lead you to conclude unequivocally that the island finch population had evolved into a distinct species, according to the biological species concept? A) Individuals from the different populations sometimes mate with each other, but all of the resulting eggs are sterile. B) The island birds all have red feathers, but the mainland birds have green feathers. C) Hybrid offspring of matings between individuals from the two populations do not look like either parent. D) The preferred food of the island birds is quite different from the diet of mainland birds. E) Individuals from the different populations frequently direct courtship behavior toward members of the other population.

Which of the following conditions is necessary for speciation to occur? A) Adaptive radiation B) Interbreeding among neighboring populations C) Sympatric speciation D) Reproductive isolation E) Mass extinction

At which point in the adaptation of a population is it clear that speciation has occurred? A) Viable, fertile hybrids occur. B) Gene pool changes establish reproductive barriers between two populations. C) An allopatric separation occurs. D) Gene pool changes adapt a population to a local environment. E) All of the listed responses are correct.

Prezygotic barriers _____. A) Are necessary in order for speciation to occur B) Prevent fertilization of gametes from members of closely related species C) Prevent a hybrid zygote from developing into a viable, fertile adult D) Only occur in asexual organisms E) Prevent donkeys and horses from mating

Three species of frogs, Rana pipiens, Rana clamitans, and Rana sylvatica, all mate in the same ponds, but they pair off correctly because they have different calls. This is a specific example of a _____ barrier, called _____. A) Prezygotic ... behavioral isolation B) Prezygotic ... temporal isolation C) Prezygotic ... gametic isolation D) Postzygotic ... mechanical isolation E) Postzygotic ... hybrid breakdown

Which of the following reproductive barriers actually prevents individuals of closely related species from copulating successfully? A) Hybrid breakdown B) Mechanical isolation C) Hybrid sterility D) Gametic isolation E) Hybrid inviability

Two species of water lilies in the same pond do not interbreed because one blooms at night and the other during the day. The reproductive barrier between them is an example of _____. A) Hybrid breakdown B) Temporal isolation C) Ecological isolation D) Gametic isolation E) Mechanical isolation

Which of the following is an example of a postzygotic reproductive barrier? A) One species of flower grows in forested areas, another in meadows. B) Two pheasant species perform different courtship dances. C) One species of frog mates in April, but another mates in May. D) The sperm of a marine worm can only penetrate eggs of the same species. E) Two fruit flies of different species produce sterile offspring.

There are two groups of pine trees that appear to be very similar phenotypically and genotypically. However, one releases pollen in January, when the female structures of that group are receptive, and one in March. What kind of reproductive barrier is this? A) Temporal isolation B) Gametic isolation C) Hybrid inviability D) Mechanical isolation E) A geographic barrier

The phylogenetic species concept emphasizes _____. A) Ecological niches B) The ability to hybridize C) Phenotypic differences D) Common ancestry E) The evolution of reproductive isolation

Lake Victoria, in Africa, is home to a group of related fishes known as cichlids. Many of these fishes are similar in appearance but have different feeding habits. What is the best method for scientists to determine conclusively whether the fish are members of a population that has a lot of variation or members of entirely different species? A) Do studies on comparative anatomy, especially looking for homologous structures. B) Study the fossil record. C) Compare DNA sequences, because the DNA of members of the same species should be identical. D) Observe the fish in their natural environment for possible instances of interbreeding leading to several generations of fertile offspring. E) All of the listed responses must be done to determine whether a single population or different species are present.

In practice, how do scientists distinguish most species? A) By using the morphological species concept B) By using the biological species concept C) By using the ecological species concept D) By using the paleontological species concept E) By using the phylogenetic species concept

Which species concept defines a species as a set of organisms with a unique genetic history? A) Paleontological species concept B) Biological species concept C) Phylogenetic species concept D) Morphological species concept E) Ecological species concept

Sometimes two phenotypically different populations interbreed to a limited extent, so that it is difficult to determine whether they are clearly separate species. This is not a concern to scientists because this _____. A) Is quite rare B) Happens only among plants, not among animals C) Is true for almost every species D) Supports the theory of punctuated equilibrium E) May indicate that the formation of a new species is in progress

Which of the following organisms is most likely to be subject to allopatric speciation? A) Whale populations of the same species located on opposite sides of the Atlantic Ocean B) Pine trees in Alaska and pine trees on the island of Madagascar C) Mountain lions in the canyons of Wyoming and in the canyons of Utah D) Fruit flies on bananas and fruit flies on oranges E) Bacteria in a hospital and bacteria in a nursery

According to the experiment of Diane Dodd, can adaptive divergence of allopatric fruit fly populations lead to reproductive isolation? A) Yes. After several generations, the reproductive barrier (behavioral isolation) between the starch- and maltose-fed populations was complete. B) No. Even after several generations, there was no evidence of a reproductive barrier forming between the populations. C) No. After several generations, the formation of a reproductive barrier (mechanical isolation) was evident, but not absolute. D) No. After several generations, the formation of a reproductive barrier (behavioral isolation) was evident, but not absolute. E) Yes. After several generations, the reproductive barrier (mechanical isolation) between the starch- and maltose-fed populations was complete.

Which of the following evolutionary mechanisms does NOT contribute to the process of allopatric speciation? A) Mutation B) Natural selection C) Genetic drift D) Gene flow E) All of the listed evolutionary mechanisms contribute to the process of allopatric speciation.

In which of the following groups has sympatric speciation been most important? A) Protozoa B) Plants C) Bacteria D) Animals E) Fungi

If a new species of plant is to be produced by means of allopolyploidy from two parental species that are 2n = 4 and 2n = 8, how many chromosomes would you expect in the somatic cells of the new species? A) 6 B) 24 C) 48 D) 12 E) None of the listed responses is correct.

A new species can arise in a single generation _____. A) In a very large population spread over a large area B) If adaptive radiation occurs C) Through geographic isolation D) If allopatric speciation occurs E) If a change in chromosome number creates a reproductive barrier

The Galápagos finches collected by Darwin are thought to have descended from a very small parent population. Different species of finches that are confined to only one or two islands most likely arose by _____. A) Polyploidy B) Sympatric speciation C) Hybridization D) Gene flow E) Allopatric speciation

In the case of the Lake Victoria cichlids, sympatric speciation has been shown to be driven by _____. A) Polyploidy B) Sexual selection C) Mechanical isolation D) Postzygotic barriers E) Habitat differentiation

In a hybrid zone, which of the following would tend to lead to reinforcement? A) Reduced hybrid fertility B) Sexual selection C) Hybrid breakdown D) Reduced hybrid viability E) All of the listed responses are correct.

In the Lake Victoria cichlids, what appears to be contributing to fusion of different species? A) Murky, polluted water is causing reduced hybrid viability. B) Overfishing C) Extinctions are being caused by the Nile perch, an introduced predator. D) The viability of cichlid eggs is being reduced by water pollution. E) Females have a difficult time visually selecting males of the same species in the murky, polluted water.

According to the punctuated equilibrium model of evolution, _____. A) Fossils of organisms that existed during periods of stasis should be as abundant as those of organisms that existed during periods of rapid change B) Polyploidy is not a mechanism of punctuated equilibrium C) The tempo of evolution consists of abrupt episodes of speciation among long periods of equilibrium D) Isolated species changing over a few thousand generations represent graduated equilibrium, not punctuated equilibrium E) None of the listed responses is correct.

Comparison of human fossils with living humans seems to show that there have been no significant physical changes in Homo sapiens in 30,000 to 50,000 years. What might an advocate of punctuated equilibrium say about this? A) That is about how long we have been reproductively isolated. B) It is impossible to see major internal changes by looking at fossils. C) It is about time for humans to undergo a burst of change. D) You would expect a lot of skeletal changes in that time period. E) Lack of change is consistent with the punctuated equilibrium model.

What is the first thing that must happen in order for speciation to occur? A) A hybrid zone must be established. B) Gene flow between populations must be interrupted. C) One of the populations must become polyploid. D) The populations must become reproductively isolated. E) A catastrophic event must cause geographic separation of two populations.

How many genes must change in order to form a new species? A) 26 B) There is no set number of genes or loci that produces a new species. Genetic and environmental factors interact. C) 14 D) 4 E) 1

The time interval between speciation events is typically _____. A) 6.5 million years B) Times between speciation events vary widely and depend on generation times, causes of speciation, environmental factors, and chance. C) 500,000 years D) 40 million years E) 4,000 years