Exam 16: The Evolution of Biodiversity

At which labeled point in the following graph are the first eukaryotes thought to have evolved?

Which of the following are unique to mammals and the most recent common ancestor of mammals but lacking in nonmammals?

Why might many new species form in the aftermath of a mass extinction?

The first single-celled prokaryotes evolved 3 billion years after the first eukaryotes.

Ninety-five percent of marine invertebrate species went extinct during the mass extinction at the end of the ____________________.

The similarities retained by two lineages because of their common ancestry are known as ________.

The first eukaryotes evolved approximately _____ years ago.

Which of the five great extinctions resulted in the largest loss of species?

You are looking at the side of a cliff with many clearly visible layers of rock.In the top layer,you find the fossil of a mouse.In the next layer down,you find the fossil of a frog.Two layers down from that,you find the fossil of a beetle and,in the deepest layer,the fossil of a millipede.This is evidence that _____________.

The morphological and genetic similarities that reflect the evolutionary histories of the organisms being studied by scientists are used to construct evolutionary trees that illustrate the patterns of species evolution.The field within which such studies are conducted is called ___________

The oldest fossils of terrestrial animals are of ___________.

Life evolved in the oceans long before it evolved on land.Which of the following had to occur before organisms were able to live on land?

Following each of Earth's five mass extinctions,the diversity of life on Earth,over time,has ____________________ [increased or decreased].

Two organisms that are more closely related will generally possess more homologous traits than two organisms that are more distantly related.

The diversification of groups of organisms to form new species that can occur after a mass extinction or at other times is called adaptive ___________.

Which of the following represents the order in which terrestrial life appeared in the fossil record?

Evolutionary novelties shared by an ancestor and its descendants but not seen in groups that are not direct descendants of that ancestor are known as ___________.

We know that whales evolved from the same evolutionary ancestor as hoofed animals like cows and hippopotamuses because ____________.

The following figure shows the number of living taxonomic families that existed on Earth during the last 540 million years.The sudden decreases in family numbers at 445,360,250,200,and 65 million years ago represent Earth's five mass extinction events.Based on these data,which mass extinction had the biggest impact on the overall diversity of life on Earth?

You are studying the relationships between a number of organisms.You begin by cataloging their homologous traits.Organisms A and B share 23 homologous traits.In addition,organisms B and C share 14 homologous traits,while organisms A and C share 11 homologous traits.Based on these preliminary findings,what can you conclude from these data?