Exam 25: Phylogenies and the History of Life

Both ancestral birds and ancestral mammals shared a common ancestor that was a terrestrial vertebrate. 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?

Refer to the following information to answer the question below. -Which of the following is the most likely explanation for the modern-day distribution of dicynodont fossils? The dicynodonts were ________.

For many years, scientists believed that almost all animal lineages burst into being during the Cambrian era (just after the end of the Precambrian super eon). However, there have been many recent findings of animal-like fossils and "trace fossils" (fossils of an animal-like organism's movement) from the late Precambrian. Which of the following best explains why it took so long to realize there was animal-like life in the Precambrian?

You are the lucky student of a wacky professor who develops a time machine. He asks if you will test it with him. You get in and there is an immediate glitch-the date readout fails so that when you land you are not sure what era you are in. Your professor begins to panic, but you see something that tells you are in the Cenozoic era. Which of the following could it be?

The term "homoplasy" is most applicable to which of the following features?

The question(s) below refer to the following paragraph. -Which of the following reasons would explain why the sediment core lacks fossils of dragonflies with 3-foot wingspans? 1) This particular sediment core includes the correct stratum, but the part of the stratum captured by the core lacks such fossils. 2) The sea was not present at this site during the time that 3-foot dragonflies existed. 3) Dragonflies have no hard parts, such as exoskeletons, to fossilize. 4) The sediments containing these fossils at this site may have been eroded away during a time when the sea had receded from this site. 5) Dragonflies are terrestrial; therefore, fossils of terrestrial organisms should not be expected in the sediments of seas.

Which of the following statements is TRUE about a phylogeny, as represented by a phylogenetic tree? I. Descendant groups (branches) from the same node do not share any derived characters. II. A monophyletic group can be properly based on convergent features. III. The ancestral group always displays all the synapomorphies of the descendant species.

How do mass extinctions differ from background extinctions?

What is still lacking in the hypothesis of an asteroid impact as the cause of the end-Cretaceous mass extinction?

Phylogenetic trees constructed from evidence from molecular systematics are based on similarities in ________.

Which of the following would be useful in creating a phylogenetic tree of a vertebrate taxon? I. morphological data from fossil species II. genetic sequences from living species III. behavioral data from living species

You are the lucky student of a wacky professor who develops a time machine. He asks if you will test it with him. You get in and there is an immediate glitch-the date readout fails so that when you land you are not sure what era you are in. As your time machine lands, you see an unusual landscape before you. As you open the door, you realize you cannot breathe. You quickly shut the door, realizing you are in the ________.

The question(s) below refer to the following paragraph. -If arrows indicate locations in the column where fossils of a particular type (see key in the accompanying figure) first appear, then which core in the figure has the most accurate arrangement of fossils?

If, someday, an Archaean cell is discovered with an rRNA sequence that is more similar to that of humans than the sequence of mouse rRNA is to that of humans, the best explanation for this apparent discrepancy would be ________.

Which listing of geological periods is in the correct order, from oldest to most recent?

Upon being formed, oceanic islands, such as the Hawaiian Islands, should feature what characteristic, leading to which phenomenon?

What must be TRUE of any organ described as vestigial?

Assuming the existence of fossilized markers for each of the following chemicals, what is the sequence in which they should be found in this sediment core, working from ancient sediments to recent sediments? 1) chitin coupled with protein 2) chlorophyll 3) bone 4) cellulose

The major evolutionary episode corresponding most closely in time with the formation of Pangaea was the ________.

The largest extinction, measured as a percentage of species that disappeared, occurred at the end of which geological period?