Scott, Eugenie C.
A human biologist specializing in medical anthropology and skeletal biology. As executive director of the National Centre for Science Education, Scott is an advocate of church/state separation in schools, and speaks widely about science, evolution, and natural selection.

Scott, Matthew P.
A professor and researcher whose work in developmental biology explores how homeotic genes orchestrate differentiation and multicellular organization.

Sedimentary rocks are deposited mainly under water, usually in approximately horizontal layers (beds). Clastic sedimentary rocks are formed from the erosion and deposition of pre-existing rocks are classified according to the size of the particles. Organically formed sedimentary rocks are derived from the remains of plants and animals, for example limestone and coal. Chemically formed sedimentary rocks result from natural chemical processes and include sedimentary iron ores. Many sedimentary rocks contain fossils.

Segregation
The normal biological process whereby the two pieces of a chromosome pair are separated during meiosis and randomly distributed to the germ cells.
2. The separation of homologous chromosomes into different gametes during meiosis.

Selective Pressures
Environmental forces such as scarcity of food or extreme temperatures that result in the survival of only certain organisms with characteristics that provide resistance.

Selfing
In plants, reproduction by self-fertilization; fertilization of an ovule by pollen from the same plant.