Exam 26: Phylogeny and the Tree of Life

The following questions refer to the description below. You are taking an art class and your instructor asks you to draw several animals,including a shark,a dolphin,and a penguin.As you draw these animals you notice that they all have a fusiform shape; in other words,they are tapered at both ends.Despite their similar shape,you are well aware that the shark is a fish,the dolphin is a mammal,and the penguin is a bird. -You are also asked to draw animals that fly,including insects,birds,and bats.You read that fossil evidence suggests that bat wings and bird wings arose independently from forelimbs of different tetrapod ancestors.If this is the case,then a bird's wing is ________ to a bat's wing.

Horizontal gene transfer

When it acts upon a gene,which of the following processes consequently makes that gene an accurate molecular clock?

Nucleic acid sequences that undergo few changes over the course of evolutionary time are said to be conserved.Conserved sequences of nucleic acids

Morphologically,species A is very similar to four other species,B-E.Yet the nucleotide sequence deep within an intron in a gene shared by all five of these eukaryotic species is quite different in species A compared to that of the other four species when we study the nucleotides present at each position. -If the sequence of species A in the above figure differs from that of the other four species due to simple misalignment,then what should the computer software find when it compares the sequence of species A to those of the other four species?

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

Linnaeus was a "fixist" who believed that species remained fixed in the form in which they had been created.Linnaeus would have been uncomfortable with

Use the following information and figure to answer the questions below. Traditionally,whales and hippopotamuses have been classified in different orders,the Cetacea and the Artiodactyla,respectively.Recent molecular evidence,however,indicates that the whales' closest living relatives are the hippos.This has caused some zoologists to lump the two orders together into a single clade,the Cetartiodactyla.There is no consensus on whether the Cetartiodactyla should be accorded order status or superorder status.This is because it remains unclear whether the whale lineage diverged from the lineage leading to the hippos before or after the other members of the order Artiodactyla (pigs,camels,etc.)diverged (see the figure below). This figure contrasts the "Within the artiodactyls" origin of the whale lineage with the "Without the artiodactyls" origin of the whale lineage. -If cetaceans are determined to have diverged from the lineage leading to the artiodactyls before the divergence of lineages leading to the modern artiodactyls (including hippos),then the cetaceans can be considered 1)a sister order to the order Artiodactyla. 2)an ingroup of the order Artiodactyla. 3)the common ancestor of the order Artiodactyla.

Which of these can be properly inferred from the phylogeny in the above figure?

In a comparison of birds and mammals,having four limbs is

A large proportion of archaeans are extremophiles,so called because they inhabit extreme environments with high acidity,salinity,and/or temperature.Such environments are thought to have been much more common on the primitive Earth.Thus,modern extremophiles survive only in places that their ancestors became adapted to long ago.Which of the following is,consequently,a valid statement about modern extremophiles,assuming that their habitats have remained relatively unchanged?