Download EVOLUTION-CHAPTER 1-3

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EVOLUTION VOCABULARY
Homologous Structures- similar structures due to common ancestor. May have
different function.
Analogous Structures- structures that have a similar function but very different
structures. ( wing of a bird and wind of a butterfly)
Fossils- remains of an organism found in rock, ice or amber (tree sap)
Relative Dating- younger fossils are closer to the surface
and older fossils are found deeper.
Absolute Dating-using Carbon 14 which gives an actual
age in millions of years
Vestigial Structures-structures that once had a function, but no longer have a
function (eyes of a cave fish or vestigial legs of a snake)
Extinct-organism that no longer exists because it was unable to adapt to a changing
environment (Dodo-couldn’t adapt to human predators)
Present Time
Artificial Selection (selective breeding)-Humans decided what animals will be bred
to select for desired traits.
Natural Selection-Survival of the fittest. Nature selects out those not adapted so
only the well adapted individuals survive and reproduce.
Competition-More organisms are born than can possibly survive. Only those best
adapted to the environment survive and reproduce. Organisms may compete for
limited food, water, nesting sites and mates.
Predators- Heterotrophs that feed on prey (other animals)
Parasites-Feed on the host but usually do not kill it (tape worms)
Genetic Variation-mutations result in some organisms in a population having
genetic differences
Antibiotic-medicine designed to kill specific types of bacteria
Speciation-over time, mutations and changes in a population result in a new
species.
Morphology-branch of biology that studies physical structure of organisms
Geographic Isolation populations of the same species are separated ( water,
mountains, desert) and can’t breed together. Over time they may evolve into
different species.
Divergent Evolution-populations of organisms become more different do to
different environments (see adaptive radiation below)
Convergent Evolution-organism that have different ancestors may become more
similar due to living in similar environments ( shape of fish, whale and penguin)
Coevolution-Two species evolve together because they depend on one another (bee
and flower, goldenrod and gallfly)
Adaptive Radiation-organisms evolve from a common ancestor into different
species to be better adapted to their environment.
Genetic Drift-small population has much different frequency of alleles than what
you would expect in the larger population (Bottleneck and Founders Effect)