Topic 1.8: Evolution and Speciation Questions

Fossils of a horse-like lineage show a long, unbroken series of forms that each differ only slightly from the one before, leading to the modern animal. Which pattern of speciation does this best illustrate?

A fossil series shows a single mammal lineage changing through a long, unbroken sequence of only-slightly-different forms, leading to one modern species. State the type of evolution shown by this lineage and its ancestors.

What is meant by the allele frequency of a population?

Define the biological species concept, and use the example of a horse, a donkey and a mule to show how it is applied.

Which of the following is the only source of brand-new alleles in a population?

A new river forms and splits one population of monkeys into two groups that can no longer reach each other. What is the immediate consequence of this separation?

Define the term evolution.

Which statement is the best definition of evolution?

Over many generations, dairy farmers have repeatedly bred only their highest-yielding cows together, and the herd's average milk yield has steadily risen. What does this best illustrate?

Under the biological species concept, which observation confirms that two organisms belong to the same species?

Outline three different lines of evidence that scientists use to support the theory that today's species evolved from earlier ones.

Which statement best defines adaptive radiation?

Two fish-eating species are found to share almost identical sequences in several of their genes. Which type of evidence for an evolutionary relationship is this?

A horse and a donkey can mate and produce a mule, but the mule is sterile. What does this tell us about horses and donkeys?

Outline how mutation, meiosis and sexual reproduction each contribute to heritable variation in a population.

Which statement about adaptive radiation, gradual speciation and abrupt speciation is correct?

A bacterial population is repeatedly exposed to an antibiotic. After several rounds of treatment, almost all of the bacteria are resistant. Which statement correctly describes how this happened?

The diagram shows the same population at two times, many generations apart. The dark allele is shaded. What does the change shown represent? [Diagram: bio-gene-pool {"startDarkPercent": 20, "endDarkPercent": 75}]

A population reproduces only asexually, producing genetically identical offspring (clones). A new disease then spreads through the area. Compared with a sexually reproducing population, how well can the clonal population adapt, and why?

A flowering plant suddenly gives rise to a new species in a single generation because its chromosome number has doubled, so it can no longer breed with its parent population. Which pattern of speciation is this?