Evolution
Change in a kind of organism over time; process by which modern organisms have descended from ancient organisms.
natural selection
A natural process resulting in the evolution of organisms best adapted to the environment which have inherited traits which tend to survive selective agents
Selective agents
the different living (biotic) and non-living (abiotic) agents that influence the survival of organisms
artificial selection
Selection by humans for breeding of useful traits from the natural variation among different organisms
Eras
Paleozoic, Mesozoic, Cenozoic, Precamrian)
Periods
(Quaternary, Tertiary)(Cretaceous, Jurassic, Triassic)(Permian, Pennsylvanian, Missisippian, Devonian, Silurian, Ordovician, Cambrian) *there is no period for precambrian era
Biogeography
Study of past and present distribution of organisms through the split of Pangea
Pangaea
The name of the single supercontinent that broke apart 200 million years ago and gave rise to today's continents
Laurasia
Occured during Paleozoic era. North America, Europe, Asia
Gondwana
Occured during Paleozoic era. South America, Africa, Australia, India, and Antarctica
plate tectonics
blocks of lithosphere that consists of the crust and the rigid, outermost part of the mantle, that move.
continential drift
hypothesis that maintained that the Earth was once a supercontinent that divided and slowly drifted a part.
Fossils
the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.
Trace fossils
provide evidence of the activities of ancient organisms e.g. nest, egg, dung, footprints
body fossil
A fossil that consists of the preserved body of an animal or plant or an imprint of the body
Mould fossil
A rock that has an impression
Cast fossil
Organism protruding
Amber fossil
Whole insect of plant trapped in tree sap that hardens to amber
Index fossil
a fossil known to have lived in a particular geologic age that can be used to date the rock layer in which it is found and date other rocks in that layer
law of superstition
the law that a sedimentary rock layer is older than the layers above it and younger than the layers below it if the layers are not disturbed with faults
half-life
The time required for one half of the atoms of a radioisotope to decay into a new element
Isotopes
Atoms of the same element that have different numbers of neutrons
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 numerical age of a fossil using radiometric dating (isotopes half lives to calculate age)
relative age
How old something is by comparing it to something else
Absolute age
The age of a rock given as the number of years since the rock formed (numerical)
fold
a bend in layers of rock, sometimes caused by plate movement and time
fault
A break in the earth's crust and layers (strata)
comparative anatomy
The study if similar physical features in organisms. Organisms that either come from the same or different ancestry.
Homologous structures
Those that DO have common ancestor. Those with similar structures but different functions. (divergent evolution)
divergent evolution
the evolutionary pattern in which species sharing a common ancestor move away and become more distinct due to differential selection pressure/natural selection/artificial selection which gradually leads to speciation (new species) over time. e.g elephants and mammoths
analogous structures
Have a similar function but different structure. DON'T have a common ancestry. (convergent evolution)
convergent evolution
The process whereby distantly related organisms independently evolve similar traits to adapt to similar necessities and over time become similar species e.g dolphins and sharks, butterflies and bats.
vestigial strutures
Structures that once had a function that now has been lost
comparative embryology
the study of the developing embryo from the zygote to the foetus.
molecular biology
One of the five evidence of evolution
phylogenetic tree
A family tree that shows the evolutionary relationships thought to exist among groups of organisms
Bipedalism
the ability to walk upright on two legs
sagittal crest
Bony projection on top of the cranium for attachment of chewing muscles (larger on apes not humans)
brow ridge
Bony projection protecting eyes. Prominent in early hominids.
foramen magnum
A large opening at the base of the skull through which the brain connects to the spinal cord.
cultural evolution
cultural change over time; not to be confused with progress