Exam 26: Speciation

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 neighboring island arrive.What effect do these new arrivals have?

The theory of plate tectonics describes movement of plates of the Earth's crust through time.Which of the following can you deduce from what you learned in this chapter about plate tectonics?

Two species of tree frogs that live sympatrically in the northeastern United States differ in ploidy: Hyla chrysocelis is diploid,and Hyla versicolor is tetraploid.The frogs are identical in appearance;but their mating calls,which females use to find mates,differ.Which difference most likely evolved first?

Which of the following does not tend to promote speciation?

Which of the following could be a vicariance event for species in that habitat?

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 by a dominant allele of one gene.By about 1900,approximately 90% of the moths around industrial areas were dark colored,whereas light-colored moths were still abundant elsewhere.Apparently,birds could readily find the light moths against the soot-darkened background in industrial areas and therefore were eating more light moths.Recently,use of cleaner fuels has greatly reduced soot in the landscape,and the dark-colored moths have been disappearing.Should the two forms of moths be considered separate species?

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 female moths primarily use scent to find these plants from afar.Females tend to mate where they feed,and the researcher finds a genetic basis for scent preference in these moths.Based on the above information,what might be occurring in this moth species?

If a plant species with 2n = 14 forms an allopolyploid with a plant species with 2n = 18,what would be the likely diploid (2n)number of the allopolyploid?

Male frogs give calls that attract female frogs to approach and mate.Researchers examined mating calls of closely related tree frogs in South America.What outcomes can occur where the ranges of two species overlap?

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.Two hypothetical species of sparrow,A and B,overwinter together in mixed flocks in Costa Rica.In spring,species A goes to the east coast of North America,and species B goes to the west coast.What can you say about the isolating mechanisms of these two 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 maturity were tetraploid,with chromosome sets of both diploid parent species.Based on these results,if this type of tetraploid formed in the wild,what would be the result? (Y.Kondo and A.Kashiwagi.2004.Experimentally induced autotetraploidy and allotetraploidy in two Japanese pond frogs.Journal of Herpetology 38(3): 381-92. )

How are two different species most likely to evolve from one ancestral species?

The two populations are _____.