Chapter 20 - History of Life

Question 1

Changes in anatomy, phylogeny, ecology, and behavior that take place in clades larger than a single species

Answer 1

Macroevolutionary Pattern

Question 2

Used to refer to a species that has died out and has no living members

Answer 2

Extinct

Question 2

Extinction caused by slow and steady progress of natural selection

Answer 2

Background Extinction

Question 3

Event during which many species become extinct during a relatively short period of time

Answer 3

Mass Extinction

Question 4

Evolution of a species by gradual accumulation of small genetic changes over long periods of time

Answer 4

Gradualism

Question 5

Pattern of evolution in which long stable periods are interrupted by brief periods of more rapid change

Answer 5

Punctuated Equilibrium

Question 6

Process by which a single species or small group of species evolve into several different forms that live in different ways

Answer 6

Adaptive Radiation

Question 7

Process by which unrelated organisms independently evolve similarities when adapting to similar environments

Answer 7

Convergent Evolution

Question 8

Process by which 2 species evolve in response to each other over time

Answer 8

Coevolution

Question 9

Distribution of continents and oceans, determined by plate tectonics, formation of islands, global climate change, and meteorite impacts

Answer 9

changes that caused major shifts in regional and global climates, affecting the evolutionary history of life

Question 10

Over deep time, actions of living organisms have changed conditions in the ___, the ___, and the ___.

Answer 10

atmosphere; oceans; land

Question 11

emergence, growth, and extinctions of larger clades (dinosaurs, mammals, flowering plants)

Answer 11

examples of macroevolutionary patterns

Question 12

Species become ___ because their environment breaks down and the ordinary process of natural selection can’t compensate quickly enough.

Answer 12

extinct

Question 13

___ evidence supports the hypothesis that evolution can occur at different rates in different clades, and at different times.

Answer 13

Fossil

Question 14

The evolution of ___ drove the first dramatic life-triggering change in global environments.

Answer 14

photosynthesis

Question 15

The thin layer of rock that forms Earth’s outer surface on land and in the ocean

Answer 15

Crust

Question 16

The layer of a scorching but mostly solid rock beneath the Earth’s crust

Answer 16

Mantle

Question 17

The sphere of Earth that’s made up of the hard rock on and just below Earth’s surface; the outermost layer of both Earth and its geosphere

Answer 17

Lithosphere

Question 18

The layer of Earth below the mantle

Answer 18

Core

Question 19

Geological processes resulting from plate movement (like volcanoes, continental drift, earthquakes)

Answer 19

Plate Tectonics

Question 20

Physical and chemical processes that break down rocks and minerals into smaller particles

Answer 20

Weathering

Question 21

Method of determining the age of a fossil by comparing its placement with that of fossils in other rock layers

Answer 21

Relative Dating

Question 22

Distinctive fossils that are used to compare the relative ages of fossils

Answer 22

Index Fossils

Question 23

Method for determining the age of a sample from the amount of radioactive isotope to the nonradioactive isotope of the same element in a sample

Answer 23

Radiometric Dating

Question 24

Length of time required for half of the radioactive atoms in a sample to decay

Answer 24

Half-life

Question 25

Timeline used to represent Earth’s history

Answer 25

Geologic Time Scale

Question 26

Major division of ecological time; usually divided into 2 or more periods

Answer 26

Era

Question 27

Division of geologic time into which eras are subdivided

Answer 27

Period

Question 28

Earth’s ___ ___ contained little to no oxygen and was mainly composed of carbon dioxide, water vapor, and nitrogen. It also had carbon monoxide, hydrogen sulfide, and hydrogen cyanide.

Answer 28

early atmosphere

Question 29

When magma reaches the upper part of the crust, it spreads sideways and solidifies, creating a new crust that’s part of an undersea mountain range called ___-___ ___.

Answer 29

mid-ocean ridges

Question 30

___ weathering occurs when water or chemically active molecules such as oxygen or acids in rain transform compounds in rocks or other materials.

Answer 30

Chemical

Question 31

___ weathering breaks up rocks and wears them down in different ways.

Answer 31

Physical

Question 32

1. water carries small rock particles to land and sea
2. dead organisms are buried by layers of sediment, which form new rock
3. preserved remains may later be discovered and studied

Answer 32

steps of fossil formation

Question 33

The geological time scale is based on both ___ and ___ dating.

Answer 33

relative; absolute

Question 34

Theory that proposes that eukaryotic cells formed from a symbiotic relationship among several different prokaryotic cells

Answer 34

Endosymbiotic Theory

Question 35

___ and ___ experiment suggest that organic compounds are necessary for life and could’ve arisen from simpler compounds on a primitive Earth.

Answer 35

Miller and Urey’s

Question 36

The ___ ___ ___ proposes that RNA existed before DNA and that several steps could’ve led to today’s DNA-directed protein synthesis.

Answer 36

RNA world hypothesis