Biology Chapter 18: The Outcomes Of Evolution

Front 1

A definition of species that relies on the breeding behavior of populations in nature. It defines species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.

Back 1

biological species concept

Front 2

The development of new species through evolution.

Back 2

speciation

Front 3

Speciation that involves the geographic separation of populations. Most speciation involves geographic separation, followed by the development of intrinsic isolating mechanisms in the separated populations.

Back 3

allopatric speciation

Front 4

Any factor that, in nature, prevents interbreeding between individuals of the same or closely related species.

Back 4

reproductive isolating mechanisms

Front 5

A barrier to interbreeding of populations that is not an inherent characteristic of the organisms in the populations. Geographic barriers such as rivers are extrinsic isolating mechanisms.

Back 5

extrinsic isolating mechanism

Front 6

A difference in anatomy, physiology, or behavior that prevents interbreeding between individuals of the same species or of closely related species.

Back 6

intrinsic isolating mechanism

Front 7

A type of speciation that occurs in the absence of the geographic separation of populations.

Back 7

sympatric speciation

Front 8

A form of sympatric speciation in which one or more sets of chromosomes are added to the genome of an organism.

Back 8

polyploidy

Front 9

The rapid emergence of many species from a single species that has been introduced to a new environment. The different species specialize to fill available niches in the new environment.

Back 9

adaptive radiation

Front 10

The system of naming species that uses two names (genus and species) for each species. This system helps identify groupings among living things.

Back 10

binomial nomenclature

Front 11

The field of biology dealing with the diversity and relatedness of organisms. These people study the evolutionary history of groups of organisms.

Back 11

systematics

Front 12

The highest-level taxonomic grouping of organisms. There are only three domains: Archaea, Bacteria, and Eukarya.

Back 12

domain

Front 13

Any of the taxonomic categories used in the classification of Earth's organisms, both living and extinct. In order of increasing inclusiveness, these categories are species, genus, family, order, class, phylum, kingdom, and domain.

Back 13

taxon

Front 14

A hypothesis about the evolutionary relationships of a group of organisms.

Back 14

phylogeny

Front 15

A structure that is shared in different organisms owing to inheritance from a common ancestor.

Back 15

homology

Front 16

A structure found in different organisms that is similar in function and appearance but is not the result of shared ancestry.

Back 16

analogy

Front 17

Evolution that occurs when similar environmental influences shape two separate evolutionary lines in similar ways.

Back 17

convergent evolution

Front 18

The branch of systematics that uses shared derived characters to determine the order of branching events in speciation and therefore which species are most closely related.

Back 18

cladistics

Front 19

An evolutionary tree constructed using the cladistic system.

Back 19

cladogram

Front 20

A character that existed in the common ancestor of a group of organisms. Cladistics distinguishes ancestral from derived characters and uses these characters to determine evolutionary relationships.

Back 20

ancestral character

Front 21

A character unique to groupings of organisms (taxa) descended from a common ancestor.

Back 21

derived character

Front 22

A taxonomic grouping subordinate to phylum and subordinate to order.

Back 22

class

Front 23

A taxonomic grouping subordinate to order and superordinate to genus.

Back 23

family

Front 24

A taxonomic grouping of related species. This category is subordinate to family and superordinate to species.

Back 24

genus

Front 25

A taxonomic grouping superordinate to every other grouping except domain.

Back 25

kingdom

Front 26

A taxonomic grouping subordinate to class and superordinate to family.

Back 26

order

Front 27

A category of living things, directly subordinate to the category of kingdom, whose members share traits as a result of shared ancestry.

Back 27

phylum

Front 28

A group of actually or potentially interbreeding natural populations that are reproductively isolated from other such populations.

Back 28

species