Exam 15: Tracing Evolutionary History

Cave-dwelling catfish and cave-dwelling salamanders share striking similarities: Both organisms lack pigmentation, and their eyes are reduced or absent. The most recent common ancestor to these organisms had normal pigmentation and fully developed eyes. The similarities between cave catfish and cave salamanders are an example of

Which of the following environments is thought to have promoted the dehydration synthesis of polypeptides and other macromolecules from smaller organic monomers on a prebiotic Earth?

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 Manx cat is in the domestic cat group, and the bobcat is in the lynx group. Both have a trait in common: short, stubby tails. According to the phylogeny, which is the most parsimonious explanation for this common trait in these two species of cat?

According to the accompanying figure, if a species were found only in Laurasia 135 million years ago, on which modern continents would its descendants most likely be found today?

In accordance with the principle of parsimony, scientists

If an isotope has a half-life of 4 million years and a fossil is 16 million years old, how much of the original isotope will be found in the fossil?

Miller was the first to show that

Scientists hypothesize that a major factor promoting the adaptive radiation of mammals was probably

In 1865, a biologist, St. George Jackson Mivart, constructed an evolutionary tree of existing primate species with many branches based on analysis of spinal columns. But to his dismay, another tree based on limb comparison was quite different. Which of the following analyses would be best to include today to determine which tree is more accurate?

The accompanying figure shows the hierarchy of classification of the cow, Bos primigenius. -Bos primigenius, the name of the cow, represents

RNA molecules that can function like enzymes are called

A current leading hypothesis about the first system of inheritance in the earliest life-forms involves

The "big bang" that produced the universe is thought to have occurred

Over the past 500 million years, there have been ________ mass extinctions, and each time, at least ________ of the species on Earth became extinct.

Over a span of several thousand years, a number of species show adaptations to climate change: Drier, warmer conditions select for succulent vegetation and deep taproots in plants, burrowing in mammals and amphibians, and other similar adaptive changes. What could be predicted to happen if the climate shifts in the opposite direction and becomes progressively wetter and cooler?

According to the accompanying figure, during what time frame was there an adaptive radiation of eutherians?

According to "evo-devo" thinking, an organism's body form can be substantially changed

Shown are phylogenetic trees of vertebrates (A) and reptiles (B). Using the data in these models, what might a Tyrannosaurus rex taste like? (A) (B)

You compare homologous nucleotide sequences among several pairs of species with known divergence times. A pair of species that diverged 1 million years ago has two nucleotide differences, a pair that diverged 2 million years ago has four nucleotide differences, and a pair that diverged 3 million years ago has six nucleotide differences. You have sequence data for another pair of species for which the divergence time is unknown. There are five nucleotide differences between them. Based on your clock, when did their line of ancestry diverge?

Which of the following options lists taxonomic categories in the correct order from most specific to most general?