Theory- A well tested concept that explains a range of observations.
Evolution- A gradual change in species over time.
Slow change. Diversity of life.
Populations accumulate inherited traits over time.
slow steady change by small steps.
quick change between long time without change, no steps.
Species- Group of similar organisms that can survive and reproduce successfully.
New species evolve due to isolation- not able to reproduce with
previous species connected with.
Species adapt to new or changing environment.
Variation- range of characteristics (traits) ie: size, color
variation is due partially by genes and part by environment.
of organisms; same species, same area, and same time.
Adaptation- Variations that make the organism better suited to the environment. Better to survive and reproduce.
help the organism successful for finding food or shelter.
Natural Selection- Pressure on population; 4 basic needs: food, water, air &
Populations best suited
for the environment will survive.
Works through steps
of overpopulation, variation, competition/adaptation and selection/survival.
Darwin- Studied many varieties of species of organisms.
wrote book The Origin
Fossils- dead organisms buried in sediment (rock and soil particles)
of evolution occuring.
provides clues of
past and new species of organisms.
and helps record time of organisms.
to study fossils.
rocks showed the earth
is very old. showed many extinct species and beginnings of species.
Sedimentary Rock- part of the rock cycle.
layered by age (time),
oldest lower and newest above.
Earth history- processes same today as in centuries past.
happen to disrupt normal process.
ie: volcano, earthquakes,
and radioactive dating places the earth at 4.6 billion years old. Life at 3 billion years.
Organisms’ change or become extinct due to adapting, or not adapting, to
environment. Natural selection.
play a part with organisms altering genetically.
Branching Diagram- see the relationship of organisms from past to present.
Helps in classification
of species due to similarities.