Habitat isolation
Two populations of birds with somewhat different coloration live on opposite sides of a peninsula. The habitat between the populations is not suitable for these birds. When birds from the two populations are brought together, they produce young whose appe
different subspecies, under the morphological species concept
Two populations of birds with somewhat different coloration live on opposite sides of a peninsula. The habitat between the populations is not suitable for these birds. When birds from the two populations are brought together, they produce young whose appe
a behavioral reproductive isolating mechanism
Three populations of crickets look very similar, but the males have courtship songs that sound different. What function would this difference in song likely serve if the populations came in contact?
Their winter habitat has no bearing on their degree of reproductive isolation.
Many songbirds breed in North America in the spring and summer and then migrate to Central and South America in the fall. They spend the winter in these warmer areas, where they feed and prepare for the spring migration north and another breeding season.
No
The peppered moth provides a well-known example of natural selection. The light-colored form of the moth was predominant in England before the Industrial Revolution. In the mid-nineteenth century, a dark-colored form appeared. The difference is produced b
the morpholoogical species, biological species, and phylogenetic species concepts
About 3 million years ago, the Isthmus of Panama (a narrow strip of land connecting North and South America) formed, dividing marine organisms into Pacific and Caribbean populations. Researchers have examined species of snapping shrimp on both sides of th
Postzygotic isolation exists between the two frog species.
The common edible frog of Europe is a hybrid between two species, Rana lessonae and Rana ridibunda. The hybrids were first described in 1758 and have a wide distribution, from France across central Europe to Russia. Both male and female hybrids exist, but
phylogenetic species concept
The approach to estimating phylogenetic trees is most like the approach of which species concept?
evolution above the species level
Macroevolution is _____.
biological
Which of the various species concepts distinguishes two species based on the degree of genetic exchange between their gene pools?
biological
There is still some controversy among biologists about whether Neanderthals should be placed within the same species as modern humans or into a separate species of their own. Most DNA sequence data analyzed so far indicate that there was probably little o
morphological
You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected.
habitat isolation
Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to which of the following reproductive isolating mechanisms?
2, 4, 1, 3
Rank the following in order from most general to most specific:
1. gametic isolation
2. reproductive isolating mechanism
3. sperm-egg incompatibility in sea urchins
4. prezygotic isolating mechanism
reduced hybrid viability
Two species of frogs belonging to the same genus occasionally mate, but the embryos stop developing after a day and then die. These two frog species separate by _____.
reduced hybrid fertility
The production of sterile mules by interbreeding between female horses (mares) and male donkeys (jacks) is an example of _____.
biological and phylogenetic
Dogs (Canis lupus familiaris) and gray wolves (Canis lupus) can interbreed to produce viable, fertile offspring. These species shared a common ancestor recently (in geologic time) and have a high degree of genetic similarity, although their anatomies vary
gametic isolation
Rocky Mountain juniper (Juniperus scopulorum) and one-seeded juniper (J. monosperma) have overlapping ranges. Pollen grains (which contain sperm cells) from one species are unable to germinate and make pollen tubes on female ovules (which contain egg cell
gene flow
What does the biological species concept use as the primary criterion for determining species boundaries?
a species
The largest unit within which gene flow can readily occur is _____.
greater percentage of difference in DNA sequence between species that inhabit deep water than between species that inhabit shallow water
About 3 million years ago, the Isthmus of Panama (a narrow strip of land connecting North and South America) formed, dividing marine organisms into Pacific and Caribbean populations. Researchers have examined species of snapping shrimp on both sides of th
genetic isolation, genetic drift, divergence
Which of the following describes the most likely order of events in allopatric speciation?
2, 3, and 6
You want to study divergence of populations, and you need to maximize the rate of divergence to see results within the period of your grant funding. You will form a new population by taking some individuals from a source population and isolating them so t
allopatrically, after the ancestral species has split into two populations
How are two different species most likely to evolve from one ancestral species?
allopatric speciation
House finches were found only in western North America until 1939, when a few individuals were released in New York City. These individuals established a breeding population and gradually expanded their range. The western population also expanded its rang
polyploidy
Most causes of speciation are relatively slow, in that they may take many generations to see changes, with the exception of _____.
The tetraploids would be reproductively isolated from both parent species.
Two researchers experimentally formed tetraploid frogs by fertilizing diploid eggs from Rana porosa brevipoda with diploid sperm from Rana nigromaculata. When they mated these tetraploid frogs with each other, most of the offspring that survived to maturi
divergence in sympatry
A researcher notices that in a certain moth species, some females prefer to feed and lay eggs on domesticated solanaceous plants like potatoes and tomatoes. Other females prefer to feed and lay eggs on wild solanaceous plants like Datura. Both male and fe
polyploidy
Two species of tree frogs that live sympatrically in the northeastern United States differ in ploidy: Hyla chrysoscelis is diploid, and Hyla versicolor is tetraploid. The frogs are identical in appearance, but their mating calls, which females use to find
sympatric speciation and habitat isolation
In a hypothetical situation, a certain species of flea feeds only on pronghorn antelopes. In the western United States, pronghorns and cattle often associate with one another in the same open rangeland. Some of these fleas develop a strong preference for
relative locations of two populations as speciation occurs
The difference between geographic isolation and habitat differentiation (isolation) is the _____.
sympatric speciation and polyploidy
Among known plant species, which of these have been the two most commonly occurring phenomena that have led to the origin of new species?
sympatric speciation; habitat differentiation
Beetle pollinators of a particular plant are attracted to its flowers' bright orange color. The beetles not only pollinate the flowers, but they mate while inside of the flowers. A mutant version of the plant with red flowers becomes more common with the
habitat differentiation
On the volcanic, equatorial West African island of Sao Tom�, two species of fruit fly exist. Drosophila yakuba inhabits the island's lowlands, and is also found on the African mainland, located about two hundred miles away. At higher elevations, and only
3 and 5
On the Bahamian island of Andros, mosquitofish populations live in various, now-isolated, freshwater ponds that were once united. Currently, some predator-rich ponds have mosquitofish that can swim in short, fast bursts; other predator-poor ponds have mos
They have been geographically isolated from each other for a longer time.
In the ocean, on either side of the Isthmus of Panama, are thirty species of snapping shrimp; some are shallow-water species, others are adapted to deep water. There are fifteen species on the Pacific side and fifteen different species on the Atlantic sid
B4
In which habitat should one find snapping shrimp most closely related to shrimp that live in habitat A4?
A1
Which of these habitats is likely to harbor the most recently diverged species?
A5 and B5
Which habitats should harbor snapping shrimp species with the greatest degree of genetic divergence from each other?
the relative shortness of time they have been separated
Which factor is most important for explaining why there are equal numbers of snapping shrimp species on either side of the isthmus?
A1 and B1
The Panama Canal was completed in 1914, and its depth is about fifty feet. After 1914, snapping shrimp species from which habitats should be most likely to form hybrids as the result of the canal?
28
Plant species A has a diploid number of 12. Plant species B has a diploid number of 16. A new species, C, arises as an allopolyploid from A and B. The diploid number for species C would probably be _____.
tend to retard adaptation to the new food plants
A small number of birds arrive on an island from a neighboring larger island. This small population begins to adapt to the new food plants available on the island, and their beaks begin to change. About twice a year, one or two more birds from the neighbo
Calls would be more different in areas of sympatry.
Male frogs give calls that attract female frogs to approach and mate. Researchers examined mating calls of closely related tree frogs in South America. If reinforcement is occurring, what would you expect if you compare the calls of the two species in zon
I, II, and III
Male frogs give calls that attract female frogs to approach and mate. Researchers examined mating calls of closely related but separate species of tree frogs in South America. What outcomes could possibly occur where the ranges of two species overlap?
I)
hybrids have lower fitness than either parent population
Reinforcement is most likely to occur when _____.
an increasing number of viable, fertile hybrids is produced over the course of the next one hundred generations
The phenomenon of fusion is likely to occur when, after a period of geographic isolation, two populations meet again and _____.
an area where mating occurs between members of two closely related species, producing viable offspring
A hybrid zone is properly defined as _____.
gene flow between distinct gene pools
In hybrid zones where reinforcement is occurring, we should see a decline in _____.
fusion
Other than predation by introduced Nile perch, the most likely explanation for the recent decline in cichlid species diversity in Lake Victoria is _____.
The alleles' heterozygosity should be higher among the hybrid toads than in toad populations distant from the hybrid zone.
A narrow hybrid zone separates the toad species Bombina bombina and Bombina variegata. What is true of those alleles that are unique to the parental species?
descended from an original colony of D. yakuba, of which there are no surviving members. The current island D. yakuba represent a second colonization event from elsewhere.
On the volcanic, equatorial West African island of Sao Tom�, two species of fruit fly exist. Drosophila yakuba inhabits the island's lowlands, and is also found on the African mainland, located about two hundred miles away. At higher elevations, and only
Build a canal linking the two ponds that permits free movement of mosquitofish, but not of predators.
On the Bahamian island of Andros, mosquitofish populations live in various, now-isolated, freshwater ponds that were once united. Currently, some predator-rich ponds have mosquitofish that can swim in short, fast bursts; other predator-poor ponds have mos
The frequency of hybrid offspring would decrease.
Suppose that a group of male pied flycatchers migrated from a region where there were no collared flycatchers to a region where both species were present. Assuming events like this are very rare, which of the following scenarios is LEAST likely?
I, II, and III are correct.
A female fly, full of fertilized eggs, is swept by high winds to an island far out to sea. She is the first fly to arrive on this island and the only fly to arrive in this way. Thousands of years later, her numerous offspring occupy the island, but none o
speciation occurred rapidly in geologic time
According to the concept of punctuated equilibrium, the "sudden" appearance of a new species in the fossil record means that _____.
a new species accumulates most of its unique features as it comes into existence
According to the concept of punctuated equilibrium, _____.
can involve changes to a single gene
Speciation _____.
at least one gene, affecting at least one phenotypic trait, must change
According to the biological species concept, for speciation to occur, _____.
A single clade (that is, a group of species that share a common ancestor) can include species that formed by gradualism and other species that formed by punctuated equilibrium.
The questions below refer to the following evolutionary tree, in which the horizontal axis represents time (present time is on the far right) and the vertical axis represents morphological change.
Which conclusion can be drawn from this evolutionary tree?