chp. 16

The breakup of Pangaea, a giant supercontinent, began about __________ years ago.

200 million

The Cambrian "explosion" is often misunderstood to mean that major animal groups appeared instantaneously, as if they showed up literally "overnight." How long did the Cambrian "explosion" actually last?

5-10

The Cambrian "explosion" occurred during the Cambrian period, about ___________ years ago.

500 million

The colonization of land, beginning about - years ago, led to a series of -events. The move onto land presented many challenges, including - or desiccation, the lack of - needed to counteract the effect of gravity experienced when organisms left their watery habitat, and the instability of - as compared to aquatic environments.

500 million adaptive radiation water loss structural support atmospheric temperatures

One of the more interesting periods in the history of Earth is the Cambrian "explosion," which lasted about - years. During this time, animals experienced multiple periods of -, resulting in many new animal phyla. Of particular interest was the advent of -, which clearly affected the pace of evolution of many animal groups, as evidenced by the rapid appearance of defensive structures, such as - and other body coverings.

5=10 million adaptive radiation predators shells

Which lines of evidence confirmed the relationship of whales to the land mammals known as artiodactyls?

NOT explosion plate tectonics

Which of the following have been proposed as possible causes for mass extinction events?

NOT global complete

Every node in a phylogenetic tree represents which of the following?

a common ancestor

Which of the following was the principal evolutionary mechanism driving the Cambrian "explosion?"

adaptive radiation

The evolution of reptiles was a major step in the evolution of vertebrates, due in part to the amniotic egg. This new evolutionary branch, known as the ___________ , includes reptiles, birds, and mammals.

amniotes

What was the first vertebrate group to colonize land?

amphibians

Unusual traits that show up as "reversions" to the ancestral state are called _________ traits.

atavistic

A(n) __________ character or trait is a novel feature that evolved in a lineage and is shared by an ancestor and its descendants.

derived

During the Cambrian "explosion," all major animal phyla appeared suddenly in the fossil record.

false

The first photosynthetic organisms were eukaryotic, algal-like organisms.

false

DNA analysis confirms the sequence of emergence of vertebrates as seen in the fossil record. Which of the following chronological sequences is correct?

fish amphibians reptiles mammals

What is the name for any preserved remains, traces, or imprints of living things that lived in the past?

fossils

Discoveries from evolutionary developmental biology have revealed groups of genes that work as "master control genes" in that they regulate the expression of other genes involved in body plan development. S

homeotic

First - evolved into -, which then evolved into - that eventually gave rise to -.

lobe amphibians reptiles mammals

Which of the following was not likely to be a challenge to the colonization of land?

low atmps

What is the term for large-scale changes that have been shaped by evolutionary forces over long time spans, such as

macroevolution

Extinction events have always been a part of life on Earth. We could broadly separate extinctions into two groups: -, during which a large percentage of major taxa, such as families, go extinct in a relatively short period of time, and -, which is an ongoing process. Without including the current mass extinction event caused by human activity, there has been a total of - mass extinction events—the most recent of which took place about - years ago and was responsible for the extinction of the -.

mass extinction background extinction 5 65 million dinosaurs

How should one interpret a phylogenetic tree in order to determine the evolutionary relationships between current species?

one should read BACK

One of the most profound events in the history of life on Earth, which led to important evolutionary inventions, such as eukaryotic cells and multicellularity, was which of the following?

photosynthesis

Which biochemical pathway evolved about 2.8 billion years ago and changed the trajectory of the evolution of life on Earth?

photosynthesis

The Earth's crust is composed of plates that are in slow, constant motion with respect to one another. Name the movement of these plates.

plate tectonics

The Cambrian explosion was a time of rapid evolutionary expansion. When did the "explosion" occur?

right before present

What were the earliest documented terrestrial animals?

spiders and millipedes

Classifying living things into groups is the goal of ____________ , and determining the evolutionary history of a lineage is the goal of ___________ .

taxonomy phylogeny

the goal of is to classify living

taxonomy phylogeny node common ancestor genus species

Conservative estimates indicate that well over ninety percent of all organisms that have ever lived on the planet are now extinct. Conversely, there is a tremendous amount of biodiversity that exists today, as 1.7 million sp

the biodiversity

Traits known as _________ traits are typically rudimentary remnants of structures that at one time had a function, whereas ________ traits are reversions to an ancestral condition.

vestigial atavistic