Exam 22: Descent With Modification: a Darwinian View of Life

The following questions refer to the evolutionary tree shown below. The horizontal axis of the cladogram depicted below is a timeline that extends from? 100 000 years ago to the present; the vertical axis represents nothing in particular. The labelled branch points on the tree (V-Z) represent various common ancestors. Let's say that only since? 50 000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species. -Which of the five common ancestors, labelled V-Z, has been least successful in terms of the percentage of its derived species that are extant?

DDT was once considered a "silver bullet" that would permanently eradicate insect pests. Today, instead, DDT is largely useless against many insects. Which of these would have been required for this pest eradication effort to be successful in the long run?

Logically, which of these should cast the most doubt on the relationships depicted by an evolutionary tree?

Of the following anatomical structures, which is homologous to the bones in the wing of a bird?

The following questions refer to the description below. You have read that soapberry bugs, Jadera haematoloma, adapt to available food sources. For example, in southern Florida, soapberry bugs feed on seeds of a native plant, the balloon vine. In central Florida, the balloon vine is rare and soapberry bugs have switched to eating seeds of an introduced species, the goldenrain tree. The seeds of the goldenrain tree fruits are much closer to the fruit surface than the seeds of the native balloon vine fruit. As a result, natural selection results in beaks that are shorter in soapberry bugs that utilize goldenrain tree fruits than those that feed on balloon vine fruit seeds. -A conservation organization has been trying to eliminate introduced species and encourage the growth/spread of native species. After several years, the balloon vine has almost totally replaced the goldenrain tree in the experimental plot. Based on your knowledge of evolution, which of the following outcomes would appear to be the most logical?

Which of the following represents an idea that Darwin learned from the writings of Thomas Malthus?

What is true of pseudogenes?

With what other idea of his time was Cuvier's theory of catastrophism most in conflict?

Which pair of structures best represents convergent evolution?

If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, then what should happen in environments from which antibiotics are missing?

DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that

Charles Darwin was the first person to propose

Both ancestral birds and ancestral mammals shared a common ancestor that was terrestrial. Today, penguins (which are birds)and seals (which are mammals)have forelimbs adapted for swimming. What term best describes the relationship of the bones in the forelimbs of penguins and seals, and what term best describes the flippers of penguins and seals?

What must be true of any organ that is described as vestigial?

Which of the following criteria is not useful when trying to determine how closely related two types of organisms are?

Which of these conditions should completely prevent the occurrence of natural selection in a population over time?

A dog breeder of long-haired and long-tailed sheepdogs has decided to select for short fur and short tails in this particular breed. The breeder selects dogs with the shortest fur in each generation and only breeds these dogs. In order to have dogs with short tails, the breeder docks the dogs' tails shortly after birth. After many generations of this artificial selection, you would expect to see which of the following characteristics in the sheepdogs.

Which of the following is not an observation or inference on which natural selection is based?

It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that

Ichthyosaurs were aquatic dinosaurs. Fossils show us that they had dorsal fins and tails, as do fish, even though their closest relatives were terrestrial reptiles that had neither dorsal fins nor aquatic tails. The dorsal fins and tails of ichthyosaurs and fish are