Ch 22 Hw assignment

You find a fossil that you think is about 350 million years old. You decide to use 235U to date a volcanic ash bed just below the key specimen. The half-life of 235U is 700 million years. If you are correct, what approximate percentage of the original 235U would you expect to remain in your sample?

75 percent

Examine the figure shown.According to the figure, a mass extinction occurred at or near the end of the _____ Period.

All of these choices are correct.

Streamlined bodies are common in many types of aquatic organisms. Dolphins (a mammal), tuna (a bony fish), penguins (a bird), and sharks (a cartilaginous fish), are all organisms with streamlined bodies that reduce friction and drag. Body shape in each of these organisms would be considered:

an analogous character.

While we can use molecular clocks based on molecular sequence data to estimate the times at which various lineages diverged, we ultimately need the _____ to calibrate the clocks.

fossil record

After you have found a new species of ape, you spend 10 years in the field seeking a fossil of its ancestor. You do not find a fossil that can be considered ancestral.This lack of fossil data:

is expected, because the fossil record is incomplete.

The figure shown represents a phylogenetic tree of vertebrate animals. According to this tree, what is the sister group to the tetrapods?

lungfish

The phylogeny shown represents a hypothesis for the evolutionary relationships among major groups of plants. If it is correct, in what order should we predict to find the fossils of these groups, in order from oldest to youngest?

moss group, ferns, conifer group, flower group

Based on the diagram shown, you predict that the earliest fossil gorilla (which may not resemble modern-day gorillas) would be _____ than the earliest fossil _____.

older; bonobo

Examine the table of characters given for four different species of flower. Based on the matrix, which tree represents the most parsimonious explanation of relatedness among these species?

phylogeny 2

Some recent discoveries of fossils surprisingly retain some coloration of feathers and skin. This is the result of the preservation of:

pigment molecules.