Chapter 22: Evolution And The Origins Of Life

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adaptive radiation

Back 1

A short burst of evolutionary activity in which many new lifeforms develop in a brief span of time from a single ancestor.

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analogous structures

Back 2

Structures that share a common function but not necessarily a common orgin.

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evolution

Back 3

An unpredictable and natural process of descent over time w/ genetic modification. Is influenced by natural selection, chance, historicale events, and changing environments.

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evolutionary tree

Back 4

Map that illustrates evolutionary change and relationships b/w life-forms.

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extinction

Back 5

the loss of a particular life-form completely.

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fossil

Back 6

Preserved remnant of an organism. Is one of our richest sources of information about life-forms that lived in the past.

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gene flow

Back 7

The physical movement of alleles caused by movement of individuals into (immigration) or out of (emigration) a population. It tends to mix pools of genes that might not otherwise mingle.

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genetic drift

Back 8

Random changes in allele frequency b/c of change events.

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hominid

Back 9

Common name for members of the family HOMINIDAE. Include present-day humans (HOMO SAPIENS) and all of their extinct ancestors of the genus AUSTRALOPITHECUS and the genus HOMO.

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hominoid

Back 10

A subgroup of primates that diverged from a common ancestor of old world monkeys to become the great apes (gibbons, orangutans, gorillas, chimpanzees)

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HOMO HABILIS

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1st distinctly human ancestor. they showed brain enlargement, changes in teeth and facial features, a decline in sexual dimorphism, and conversion to a diet that included meat. May also have used tools.

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HOMO SAPIENS

Back 12

Genus and species of moderm humans, thought to envolved about 140,000 to 100,000 years ago.

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homologous structures

Back 13

body structures that share a common origin.

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macroevolution

Back 14

Large-scale evolutionary trends or changes that apply to a whole groups of spices, often as a result of changing environments or major historical events.

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mammal

Back 15

vertebrates that have hair during all or part of their lives, and mammary glands.

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microevolution

Back 16

Evolution as a result of genetic changes that give rise to new species.

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natural selection

Back 17

the process by which, according to Darwin, individuals w/ traits that make them more fit for their local environments tend to survive and reproduce. most changes in allele frequency in a population are the result of mutuations coupled with.

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population

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A group of individuals pf the same species that occupy the same geographic area and interact w/ each other.

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primate

Back 19

an order of mammals w/ five digits on their hands, fairly flat fingernails and toenails, and forward-facing eyes adapted for stereoscopic vision.

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species

Back 20

the smallest classification category of life. Is a group of organisims that under natural conditions tend to breed within that group.

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vestigial structures

Back 21

A structure that may have had a function in some ancestor but which no longer serves any function. the human coccyx is a ..... structure.

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biogeochemical cycle

Back 22

A cycle in which the chemicals that compose living organisms are recycled b/w organisms and Earth itself.

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biomass

Back 23

total living component of an ecosystem.

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biosphere

Back 24

The portion of the surface of Earth (land, water, and air) inhabited by living organisms.

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biotic potential

Back 25

Maximum growth rate of a population under ideal conditions.

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carnivore

Back 26

Organism that feedsonly on animals.

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carrying capacity

Back 27

the maximum number of individuals in a population that a given environment can sustain indefinitely.

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community

Back 28

Array of several different populations that coexist and interact within the same environment.

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consumer

Back 29

In ecosystems, an organism that cannot produce its own food and must feed on other organisms. Also called a heterotroph

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decomposer

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An organism that obtains energy by chamically breaking down the products, wastes or remains of other organisms.

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demographic transition

Back 31

A progression of changes followed by many nations in which the society gradually moves from poor living conditions and a high death rate to improve economic conditions in a declining death rate.

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denitrification

Back 32

A process in which nitrate is converted to nitrogren gas

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Ecological pyramid

Back 33

Graph representing the bio mass

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Ecology

Back 34

Study of the relationship between organism and their physcal environment.

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Ecosystem

Back 35

All living organism, all matter and all energy in a given environment.

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Environmental resistance

Back 36

Factors in the environment that limit population growth in particular geographic area.

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Fertility rate

Back 37

Number of children that each female has during her life time.

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Foot web

Back 38

Depicts interactions between producers and consumers in an ecosystem

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Fossil fuels

Back 39

A carbon containing compound (coal, oil or gas)that was formed millions of years ago and they convert by sediment

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Geographic range

Back 40

The area of earth over which a particular species is distributed.

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Habitat

Back 41

The type of locations where an organism chooses to live.

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Herbivore

Back 42

only eats plants

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Niche

Back 43

The role of an organism in its community

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Nitrifications

Back 44

The formation of nitrates by any of several means including nitrifying bacteria, lightening and nitrate producing fertilizer factories.

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Nitrogen fixation

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The process whereby certain bacteria coinverts nitrogen gas to amonium

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omnivore

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Eats plants and animals

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photosynthesis

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the process by which plants capture the energy in sunlight and convert it into chamical energy for their own use.

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population

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A group of individuals of the same species that occupy the same geographic are and interact with each other.

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producer

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An organism that makes its own organic molecule from inorganic compounds foum in water, air and soil, utilizing energy provided by the sun. Also called an autotroph

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replacement fertility rate

Back 50

2.1 children per woman.