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58 terms

science ch. 14 and 15

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evolution
change in a kind of organism over time; process by which modern organisms have descended from ancient organisms
adaptation
inherited characteristic that increases an organism's chance of survival
descent with modification
process by which descendants of ancestral organisms spread into various habitats and accumulate adaptations to diverse ways of life
natural selection
process by which individuals that are better suited to their environment survive and reproduce most successfully; also called survival of the fittest
fossil
preserved remains or evidence of an ancient organism
fossil record
information about past life, including the structure of organisms, what they ate, what ate them, in what environment they lived, and the order in which they lived
extinct
no longer existing
homologous structures
similar structures that related species have inherited from a common ancestor
vestigial structures
remnant of a structure that may have had an important function in a species' ancestors, but has no clear function in the modern species.
population
group of individuals of the same species that live in the same area
variation
Differences between members of the same species.
artificial selection
selective breeding of domesticated plants and animals to produce offspring with desired genetic traits
gene pool
combined genetic information of all the members of a particular population
microevolution
evolution on the smallest scale—a generation-to-generation change in the frequencies of alleles within a population
hardy-weinberg equilibrium
condition that occurs when the frequency of alleles in a particular gene pool remain constant over time
genetic drift
random change in allele frequencies that occurs in small populations
gene flow
exchange of genes between populations
fitness
ability of an organism to survive and reproduce in its environment
biological species concept
definition of a species as a population or group of populations whose members can breed with one another in nature and produce fertile offspring
macroevolution
large-scale evolutionary changes that take place over long periods of time
speciation
formation of new species
reproductive isolation
condition in which a reproductive barrier keeps two species from interbreeding
geographic isolation
separation of populations as a result of geographic change or migration to geographically isolated places
adaptive radiation
evolution from a common ancestor of many species adapted to diverse environments
punctuated equilibrium
pattern of evolution in which long stable periods are interrupted by brief periods of more rapid change
embryology
study of multicellular organisms as they develop from fertilized eggs to fully formed organisms
geologic time scale
scale used by paleontologists to represent evolutionary time
radiometric dating
the process of measuring the absolute age of geologic material by measuring the concentrations of radioactive isotopes and their decay products
half-life
the period of time in which half of a radioactive substance decays
continental drift
the hypothesis that the continents slowly move across Earth's surface
mass extinction
When many types of living things become extinct at the same time.
darwin's two main points
Descent with modification and Natural Selection
evidence of change
1.homologous structures
2. vestigial structures
3. embryos have similar stages of development
4. molecular biology
contrivance
modified for new use
pesticide resistance
1. natural selection screens traits available
2. natural selection favors traits that fit current environment
changes in the gene pool
1. natural selection
2. genetic drift
the bottle neck effect
When a population is srunk by external factors causing sudden species change.
founder effect
when a few individuals become isolated from a larger population, this smaller group may establish a new population whose gene pool isn't reflective of the source population
reproductive barriers between species
1. timing (different breeding seasons)
2. behavior
3. habitat
4. reproductive structures are incompatible
5. offspring can be infertile
geographic isolation and speciation
1. populations are separated
2. changes in the gene pool occur
3. genetic differences evolve
4. the two populations can no longer interbreed
gradualism
a model of evolution in which gradual change over a long period of time leads to biological diversity
refinement of existing adaptations
complex structures can evolve from simpler structures having the same basic function
Ex: complex eye
adaptations of existing structures to new functions
example: penguin wings have been modified for swimming
relative dating
method of determining the age of a fossil by comparing its placement with that of fossils in other layers of rock
absolute dating
A technique used to determine the actual age of a fossil
taxonomy
the science of describing, naming, and classifying organisms
linnaean system
Kingdom, Phylum, Class, Order, Family, Genus, Species
divergent evolution
when two or more species sharing a common ancestor become more different over time
convergent evolution
the process by which unrelated species become more similar as they adapt to the same kind of environment
analogous structures
structures that do not have a common evolutionary origin but are similar in function
clads
distinctive branches in history of life
6 kingdom system
Animalia, Plantae, Fungi, Protista, archaebacteria, Eubacteria
three domain system
A system of taxonomic classification based on three basic groups: Bacteria, Archaea, and Eukarya
hearing
absence of external ears; theory of bone and tissue (fat) conduction
how dolphins produce sounds
1. echolocation
2. releasing air through blowhole
cerebrum
large part of the brain that controls the senses and thinking
cerebellum
the "little brain" attached to the rear of the brainstem; it helps coordinate voluntary movement and balance
medulla oblongata (brain stem)
the part of the brain that controls involuntary actions, like breathing