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Evolutionary Theories
Evolution – the process of change over time
Pangaea – a supercontinent made up of all the world’s present
landmasses joined together
Natural Selection – the theory that explains how populations can
eventually evolve into new species
Adaptation – a trait or structure that improves an organism’s chance
for survival and reproduction
Continental Drift – the process by which the continents split apart
from a single landmass
Theory of Plate Tectonics – a theory that states that Earth’s
lithosphere, or land, is broken into large sections called tectonic
plates that move and change position over time
Lithosphere – the uppermost layer of Earth, made up of crust and
mantle
Tectonic Plates – giant chunks of land or ocean floor
Asthenosphere – the soft layer of the mantle made up of semisolid
rock that flows slowly
Convergent Boundary – the location where two tectonic plates
push together
Divergent Boundary – the location where two tectonic plates pull
apart
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Transform Boundary – the location where two tectonic plates slide
past each other
Subduction – the process in which one tectonic plate is pushed
under another tectonic plate
Volcano – an opening in Earth through which magma is released
Magma – molten material beneath or within the Earth’s crust from
which igneous rock is formed
Lava – magma that reaches Earth’s surface
Earthquake – the shaking of Earth’s surface that occurs when
energy stored as pressure in rocks is released quickly
Fault – a break or crack in Earth’s surface along which movement
occurs
Hot Spot – an area of volcanic activity in the middle of a tectonic
plate
Weathering – process in which rocks are broken down into smaller
pieces through the action of wind, water, roots, and animals
Mechanical Weathering – the process that breaks rocks apart
without changing their chemical composition
Chemical Weathering – a process that changes the chemical
composition of rocks