Exam 20: Phylogeny

The common ancestors of birds and mammals were very early (stem)reptiles,which almost certainly possessed three-chambered hearts (two atria,one ventricle).Birds and mammals,however,are alike in having four-chambered hearts (two atria,two ventricles).The four-chambered hearts of birds and mammals are best described as

Although hummingbirds and house flies both use wings to fly,this similarity is not based upon closely shared ancestry but rather on evolution and adaptation as a result of survival and reproduction in a given environment.The term best describing such a phenomenon is

A potential source of confusion in constructing a phylogeny tree is similarity between organisms that is due to

What evidence suggests that limbless bodies are the result of convergent evolution of snakes and lizards?

Figure 20.2 -Using the phylogeny drawn in Figure 20.2,which other event occurred closest in time to the divergence of gorillas from the lineage that led to humans and chimpanzees?

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

From the list below,select the correct format for the binomial (scientific name)of the species the monarch butterfly.

Which kind of DNA should provide the best molecular clock for determining the evolutionary relatedness of several species whose common ancestor became extinct billions of years ago?

Figure 20.2 -Using the phylogeny drawn in Figure 20.2,assuming chimpanzees and gorillas are humans' closest relatives,removing humans from the great ape clade and placing them in a different clade has the effect of making the phylogenetic tree of the great apes

It was once thought cetaceans had evolved from an extinct group of mammals called the mesonychids.If,in the future,it is determined that some organisms currently classified as cetaceans did actually evolve from mesonychids,whereas other cetaceans evolved from artiodactyl stock,then what will be true of the order Cetacea?

Which kingdom has been replaced with two domains?

What kind of evidence has recently made it necessary to assign the prokaryotes to either of two different domains rather than assigning all prokaryotes to the same kingdom?

Figure 20.3 -In Figure 20.3,phylogeny branch lengths represent genetic changes.Which organism on the tree has undergone the most genetic changes since divergence from common ancestor?

Which statement about the relationship between phenotypic and genetic attributes is correct?

Please use the following information 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 Figure 20.5). Figure 20.5 -What can be properly inferred from Figure 20.5?

A shared ancestral character is

A phylogenetic tree shows that birds and crocodiles share many features.A hypothesis based on this tree predicts that these features are present in a common ancestor.Which of these predicted traits is supported by fossil evidence?

Researchers obtained the data depicted in this figure by sampling human blood containing HIV and then isolating and sequencing genes within the human immunodeficiency virus's DNA .What does the y-axis represent?

The observation that genetic mutations in the genome appear to accumulate at constant rates across a wide diversity of taxa led to the development of

Regarding these sequence homology data,the principle of maximum parsimony would be applicable in