a truth known by actual experience or observation; something known to be true and verifiable by others.
A set of principles used to explain a group of facts. It has been repeatedly tested and is widely accepted. A theory can be used to make predictions about the natural world
A phenomenon of nature that has been proven to invariably occur whenever certain conditions exist or are met
A personal mental attitude of acceptance of a proposition without any evidence to guarantee its truth.
Differential reproductive success of phenotypes resulting from interaction with the natural environment.
Number and relative abundance of species in a biological community. Example: Seven species of grass plants in the same prairie
A group of individuals with similar anatomical characteristics and capable of interbreeding to produce fertile offspring
Differences in characteristics among individual species. Example: The length of the abdomen in 1 species of adult beetle varies an average of 1.5 mm
Any alteration of structure, behavior, or function that makes an organism more reproductively successful.
Coming to an end or dying out of a species, for example: The dodo bird (Raphus cucullatus).
The theory that explains how large pieces of the lithosphere, called plates, move and change shape
Isotopes (of elements)
one of two or more atoms that have the same atomic number but different number of neutrons
Half Life (of isotopes)
the time required for one half of the atoms of a given amount of a radioactive substance to disinagrate