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Flashcards in Chapter 4 Deck (26):
1

Species

is a set of individuals that can mate and produce fertile offspring

2

Biomass

large regions such as forests, deserts, and grasslands with distinct climates and certain species (especially vegetation) adapted to them

3

Fossils

mineralized or petrified replicas of skeletons, bones, teeth, shells, leaves, and seeds, or impressions of such items found in rocks

4

Biological Evolution

the process whereby earth’s life changes over time through changes in the genetic characteristics of populations

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Theory of Evolution

all species descended from earlier, ancestral species

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Natural selection

in which individuals with certain traits are more likely to survive and reproduce under a particular set of environmental conditions than are those without the traits

7

Mutations

random changes in the DNA molecules

8

Adaptation

The favored individuals possess heritable traits that give them some advantage over
other individuals in a given population

9

Differential Reproduction

which enables individuals with the trait to produce more surviving offspring than other members of the population produce

10

Speciation

one species splits into two or more different species

11

Geographic Isolation

occurs when different groups of the same population of a species become physically
isolated from one another for a long period of time

12

Reproductive Isolation

mutation and change by natural selection operate independently in the gene pools of geographically isolated populations

13

Extinction

process in which an entire species ceases to exist (biological extinction) or a population of a species becomes extinct over a large region, but not globally

14

Endemic Species

Species that are found in only one area

15

Background Extinction

species have disappeared at a low rate

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Mass Extinction

significant rise in extinction rates above the background level

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Species Diversity

the number and variety of species it contains

18

Ecological Niche

Scientists describe the role that a species plays in its ecosystem

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Generalists Species

have broad niches

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Specialists Species

occupy narrow niches

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Native Species

are those species that normally live and thrive in a particular ecosystem

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Nonnative Species

Other species that migrate into, or are deliberately or accidentally introduced into, an ecosystem

23

Indicator Species

Species that provide early warnings of damage to a community or an ecosystem

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Keystone Species

species whose roles have a large effect on the types and abundance of other species in an ecosystem

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Foundation Species

species that play a major role in shaping their communities by creating and enhancing their habitats in ways that benefit other species

26

Biodiversity

the variety of the earth’s species, or varying life-forms, the genes they contain, the ecosystems in which they live, and the ecosystem processes of energy flow and nutrient cycling
that sustain all life