bio 152 speciation hw quiz + lecture quiz on speciation and drift

Helianthus annuus and Helianthus petiolaris both share a common ancestor and live with overlapping territories. Both are well suited to their environment and are flourishing. A hybrid, Helianthus anomalus exists. It cannot interbreed with the parental species, but is well adapted to slightly drier spots (still in the same general geographical area). Which of the following concepts describes this situation?

A hybrid zone showing stability

You are maintaining a small population of fruit flies in the laboratory by transferring a quarter of the the offspring flies to a new culture bottle after each generation. After several generations, you notice that the viability (if you don't know what viability means try this link) of the flies has decreased greatly. The best way to reverse this trend is to

Ask your friend who also works on flies to give you some fresh wild type flies from the population she maintains in another lab.

Which of the following factors would not contribute to allopatric speciation?

Gene flow between the two populations is extensive.

Diane Dodd took one species of fruit flies split it into two groups. She raised one on maltose based food and the other on a starch based food for several generations (both are stressful and the populations took a long time to establish). At the end of the experiment she mixed the flies to see if they would interbreed. The maltose raised flies showed a strong preference for other maltose raised flies whereas the starch flies showed a strong preference for starch. Which of the following are true regarding this experiment (more than one possible)?

If Dr. Dodd had transferred a few flies between each colony every generation, the mating preferences would have been less likely to develop. , This is a laboratory simulation of alopatric speciation

mechanical isolation

Morphological differences prevent fertilization. prevents 2 species from interbreeding with one another

allopatric speciation

The formation of new species in populations that are geographically isolated from one another. 2 species that live in different lands

sympatric speciation

The formation of new species in populations that live in the same geographic area. 2 groups that live in the same land

Two closely related populations of mice have been separated for many generations by a river. Climatic change causes the river to dry up, thereby bringing the mice populations back into contact in a zone of overlap. Which of the following is not a possible outcome when they meet?

They interbreed in the region of overlap, producing an inferior hybrid. Subsequent interbreeding between inferior hybrids produces progressively superior hybrids over several generations.

It is thought that polar bears originated from a population of brown bears (grizzlies) that became geographically isolated during a glaciation event that occurred about 150,000 years ago. This is an example of:

allopatric speciation

A drawback of the BSC is that it cannot be applied to

asexual organisms like bacteria extinct organisms like dinosaurs

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 mosquitofish that can swim continuously for a long time. When placed together in the same body of water, the two kinds of female mosquitofish exhibit exclusive breeding preferences. Which type of reproductive isolation operates to keep the mosquitofish isolated, even when fish from different ponds are reunited in the same body of water?

behavioral isolation

The differences in these mating rituals prevents mating between the wrong birds of paradise.

behavioral isolation

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 widely. Judging from this evidence, which two species concepts are most likely to place dogs and wolves together into a single species?

biological and phylogenetic

A bacteriologist is studying two asexually reproducing strains of E. coli. The two require different amounts of trace minerals for survival; on these grounds, the bacteriologist determines that they are separate species. In making his determination, he is using what species concept?

ecological species concept

temporal isolation

form of reproductive isolation in which two populations reproduce at different times (different seasons)

A small group of naked mole rats is isolated from the colony during a flood. They land on an isolated island and find it to their liking, which is a good thing because they can't get back to the mainland. They are fruitful and they multiply, ultimately leading to a new population on the isolated island. This population's long term allelic frequencies will most likely be affected by (pick all that apply).

founder effect, genetic drift

What does the biological species concept use as the primary criterion for determining species boundaries?

gene flow (the ability to exchange alleles and genes during reproduction)

A hypothetical endangered species of wildflower has been reduced to a single small population in a mountain meadow wildlife sanctuary. A group takes over the meadow in an act of anti-government defiance. They trample all but three of the flowers. This could result in what for the gene pool of this wildflower?

genetic drift

Sheep and goats can mate but the resulting embryos do not make it to term and are not born alive.

hybrid inviability

Lions and tigers can mate to produce Ligers or Tigons (depending on which is the mom), but the offspring are only infrequently able to have offspring of their own.

hybrid sterility

behavioral isolation

isolation between populations due to differences in courtship or mating behavior

There are twenty species of bush babies living in Africa. Unfortunately the species can't just have a reproductive free-for-all because the distinctive shape of the male genitalia of each species matches the female genitalia of that species.

mechanical isolation

The non-adaptive mechanisms of evolutionary change are:

migration (gene flow), mutation, and genetic drift.

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. Which species concept will you have to use?

morphological

When you use a field guide to identify a species by its appearance, you are applying the

morphospecies concept

peripatric speciation

occurs when peripheral populations become geographically isolated from the main population and undergo genetic divergence and speciation

Two species of frog mate in the same pond. One breeds in early summer and one in late summer. This is an example of what kind of reproductive isolation?

pre-zygotic, temporal separation

The result of gene flow between populations is to ________ genetic differences among populations

reduce

parapatric speciation

speciation occurring when two populations have continuous distributions and some phenotypes in that distribution are more favorable than others

_is the process in which two groups of organisms living the same habitat diverge into separate species

sympatric speciation

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 passage of time. A particular variant of the beetle prefers the red flowers to the orange flowers. Over time, these two beetle variants diverge from each other to such an extent that interbreeding is no longer possible. What kind of speciation has occurred in this example, and what has driven it?

sympatric speciation; habitat differentiation

The eastern spotted skunk and the western spotted skunk have overlapping geographic ranges but the eastern mates in the summer and the western mates in winter. Therefore there is no gene flow between the species.

temporal isolation