Exam 15: Tracing Evolutionary History

The first fossil of Archaeopteryx, which lived about 150 million years ago, was found in the Solnhofen Quarry in Germany. Archaeopteryx has an interesting collection of characters that led to the hypothesis that it represented an evolutionary transition between modern-day birds and small bipedal dinosaurs. The fossil reveals the imprint of feathers, which connect Archaeopteryx to birds, although they do not present direct evidence of flight. Unlike birds, however, Archaeopteryx was shown by the fossil record to have had teeth, functional claws on the wings that may have been used for climbing trees or holding prey, and a long, bony tail. Birds have a fused collarbone, which was found in Archaeopteryx as well. However, the structure of the sternum differed between the two. In birds, the sternum is keeled (raised and slightly concave); the keel of the sternum serves as an attachment site for the flight muscles. Archaeopteryx had a flat sternum, similar to that found in reptiles. -If you were constructing a phylogenetic tree for the evolution of birds, which characters found in Archaeopteryx might provide evidence that birds and dinosaurs had a common ancestor?

What was the probable role of oxygen gas in the early stages of life's appearance on Earth?

Which of the following would violate the assumptions of the molecular clock?

Which of the following lines of evidence suggests that lungfishes evolved while Pangaea was intact?

The first fossil of Archaeopteryx, which lived about 150 million years ago, was found in the Solnhofen Quarry in Germany. Archaeopteryx has an interesting collection of characters that led to the hypothesis that it represented an evolutionary transition between modern-day birds and small bipedal dinosaurs. The fossil reveals the imprint of feathers, which connect Archaeopteryx to birds, although they do not present direct evidence of flight. Unlike birds, however, Archaeopteryx was shown by the fossil record to have had teeth, functional claws on the wings that may have been used for climbing trees or holding prey, and a long, bony tail. Birds have a fused collarbone, which was found in Archaeopteryx as well. However, the structure of the sternum differed between the two. In birds, the sternum is keeled (raised and slightly concave); the keel of the sternum serves as an attachment site for the flight muscles. Archaeopteryx had a flat sternum, similar to that found in reptiles. -The feathers of Archaeopteryx may have been used for flight. However, it is likely that they were originally used for

Which of the following options correctly lists the varieties of life in the order that they appear in the geologic record, from earliest to most recent?

The family Felidae (cats) is distributed across Africa, Eurasia, North America, and South America and is hypothesized to have eight major lineages (Panthera, bay cat, caracal, ocelot, lynx, puma, leopard, and domestic cat groups) as shown in this phylogenetic tree, constructed from DNA sequences. Scientists used a molecular clock and fossil evidence to date the divergence of each group. The dates of divergence are provided in the accompanying figure. -The banded linsang is not a member of the Felidae. Its inclusion in this evolutionary analysis is to

If all of Earth's history were compressed into an hour, humans would first appear less than

Which of the following options lists major events in the history of life on Earth in the proper order, from earliest to most recent?

Which statement regarding genetics is false?

The first organisms on Earth were very small, but now when you look around you see many large organisms. Which is the best explanation for this observation?

Feathers are an example of a(n) ________; they originally evolved ________.

The example of ocean and lake stickleback fishes indicates that morphology can be altered by

Miller-type experiments have shown that

The earliest discovered fossils are of ________ dating back to ________ years ago.

Potassium-40 can be used to date ________ that are ________ old.

At the end of the ________ period, over 96% of marine species and many terrestrial species became extinct, possibly because intense volcanic activity warmed Earth's climate.

The similarities in function of hummingbird wings and the wings of a butterfly reflect

Scientists evaluating the Cretaceous mass extinction have concluded that

The accompanying figure shows the hierarchy of classification of the cow, Bos primigenius. -H, I, and J at the base of the hierarchy represent