Bio 160 MB Chapter 25

Approximately how far back in time does the fossil record extend?

3.5 billion years

Ichthyosaurs, now extinct, were aquatic reptiles with dorsal fins and tails, similar to those of fish. Their most recent ancestors were terrestrial reptiles that had neither dorsal fins nor aquatic tails. The dorsal fins and tails of ichthyosaurs and fish are .......

Adaptations to a common environment and examples of convergent evolution.

Which of the following statements about adaptive radiation is correct?

Adaptive radiation occurs within a single lineage.

All of the following events can trigger an adaptive radiation except.............

An unusual event splitting a habitat, such as a severe hurricane.

Choose the best definition of a fossil.

Any trace of an organism that lived in the past.

How do lizard species on mainland California compare in diversity to those found on islands?

Due to more open ecological opportunities on a given island, greater differences occur between island species.

Which is strong evidence supporting the impact hypothesis for the extinction of the dinosaurs?

Extremely high quantities of iridium in rocks that formed around 65 million years ago.

The evolution of different ecomorphs on the Caribbean islands is an example of stabilizing selection.

False

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 the humans, the best explanation for this apparent discrepancy would be ................

Homoplasy

Which organisms are not examples of an adaptive radiation?

Mammals and reptiles in the post-dinosaur age

How do mass extinctions differ from background extinctions?

Mass extinctions cause a larger proportion of organisms to go extinct than background extinctions

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

Mutations to homologous genes

Did whales evolve from hippos?

No, but they both share a recent common ancestor

Fossilization continues even today. If you wanted to increase the probability that your deceased favorite pet would become fossilized, what actions would you take?

Place the corpse in an environment where decomposition is slow (such as a swamp or bog).

Which statement about fossilization is correct?

Rare, local, or ephemeral species leave a poor fossil record.

The best classification system is that which most closely ................

Reflects evolutionary history

Which statement represents the best explanation for the observation that the nuclear DNA of wolves and domestic dogs has a very high degree of sequence homology? Dogs and wolves..........

Share a very recent common ancestor

When using a cladistic approach to systematics, which of the following is considered most important for classification?

Shared derived characters

What was the main selective pressure behind the evolution of different Anolis lizard species in the Caribbean?

Specific ecological niches

Which of the following statements about the evolution of Anolis lizards in the Caribbean islands is true?

The phylogeny of ecomorphs on a given island reveals that adaptive radiation has taken place.

Members of two different species possess a similar-looking structure that they use in a similar way to perform about the same function. Which of the following would suggest that the relationship more likely represent homology instead of convergent evolution?

The two species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical.

Given that phylogenies are based on shared derived characteristics, which of the following traits is useful in generating a phylogeny of species W, X, Y, and Z.

Trait 2

Convergent evolution is said to have occurred if the mouse species on two islands with similar habitats are found to have similar characteristics even though they originated from different species that did not have these characteristics.

True

Which Anolis lizard ecomorph has long legs?

Trunk/ground

If you were using cladistics to build a phylogenetic tree of cats, which of the following which be the best outgroup?

Wolf

Which structures are homologous?

oak leaf and maple leaf