23. Speciation

Define 'biological species.'

Name the two types of speciation represented by this diagram. For each type, describe how reproductive barriers may develop between the new species.

What distinguishes a morphospecies?

a. It has distinctive characteristics, such as size, shape, or coloration.

b. It represents a distinct branch in a phylogeny of populations.

c. It is reproductively isolated from other species.

d. It is a fossil from a distinct time in Earth history.

Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian Islands have different elaborate courtship rituals. These rituals involve fighting other males and making stylized movements that attract females. What type of reproductive isolation does this represent?

a. Habitat isolation

b. Temporal isolation

c. Behavioral isolation

d. Gametic isolation

Fill in the blanks in the following concept map.

Which of the following describes vicariance?

a. Small populations coalesce into one large population.

b. A population is fragmented into isolated subpopulations.

c. Individuals colonize a novel habitat.

d. Individuals disperse and found a new population.

Add labels to the figure that follows, which illustrates the three steps required for speciation to occur.

What determines the primary structure of a DNA molecule?

a. Stem-and-loop configuration

b. Complementary base pairing

c. Deoxyribonucleotide sequence

d. Hydrophobic interactions and hydrogen bonding

What type of bond is directly involved in the formation of an α-helix?

a. Peptide bonds between amino acid residues

b. Hydrogen bonds between amino acid residues

c. Van der Waals interactions between nonpolar residues

d. Disulfide bonds between cysteine residues

According to the punctuated equilibria model:

a. Given enough time, most existing species will branch gradually into new species.

b. Most new species accumulate their unique features relatively rapidly as they come into existence, then change little for the rest of their duration as a species.

c. Most evolution occurs in sympatric populations.

d. Speciation is usually due to a single mutation.

Which concept of species would be most useful to a field biologist identifying new plant species in a tropical forest?

a. Biological

b. Ecological

c. Morphological

d. Phylogenetic

Select True or False to indicate which of the following groups could be identified using the biological species concept.

T/F lizard species living today

T/F sunflower species living today

T/F extinct dinosaurs

T/F bacteria living today

Molecular zip codes direct molecules to particular destinations in the cell. How are these signals read?

a. They bind to receptor proteins.

b. They enter transport vesicles.

c. They bind to motor proteins.

d. They are glycosylated by enzymes.

What type of information is used to direct different polypeptides to fold into different shapes?

Which of the following is an example of a prefertilization barrier to reproduction?

a. A female mammal is unable to carry a hybrid offspring to term

b. Hybrid plants produce only sterile pollen

c. A hybrid between two bird species cannot perform a mating display

d. A male fly of one species performs a 'wing-waving' display that does not convince a female of another species to mate with him

e. A hybrid embryo is not able to complete development