Dr. Hensley & Mrs. Ingram
April 2016
Evolution Unit - Vocabulary
Evolution – Change in a population over a long time
Fossil – Why we may not have a complete fossil record?
 Preserved remains of living organisms
 Evidence of old organisms
 Organism was too soft to fossilize
 Location not good
 Fossil not found yet
Lamark’s Theory – Strive for perfection; Use it or lose it (make good better and get rid of
what isn’t working); Believed acquired traits are passed on to offspring.
Charles Darwin – “If Earth could change, why not living things too?” He came up with the
“Survival of the Fittest” idea.
Darwin’s Theory – “Survival of the Fittest”
1. Individuals are different
2. Because of differences, some have advantages and some disadvantages
3. Organisms over produce because some will die
4. If there are more organisms than resources organisms will complete
5. Survival of the fittest – will pass onto offspring
6. Species change (evolve) over a loooooong period of time
7. Stuff from old became a new species
8. All living things come from a common ancestor
Natural Variation – The natural differences among a species
Ex: cow that produces more milk than another of the same species
Natural Selection – Survival of the fittest – Nature chooses organisms best suited to
environment will survive.
Artificial Selection – Humans choose “breeding” of species
Survival of the Fittest – Ability of an organism to survive and reproduce; Advantages =
(FITNESS) in an organism’s traits that increase chance of survival
Adaptation – Good inherited characteristic/trait that increases an organism’s fitness
their
Descent with Modification – Change in a species over time (species evolve)
Common Descent – All species come from common ancestor
Homologous Structure – Structure from same ancestor; has same function; found in
different species. Example: Legs of these animals came from same ancestor and do the
same function of motion/movement
Same ancestor
Same bone
structure
Same movement
Different species
Analogous Structure – Came from different ancestors; has similar function Example: Wings
of bird, insect, and bat do same function but came from different ancestors
Different ancestor
Similar function
Different structure
Different species
Vestigial Structures – Traces of an organ that once had a function; “Left over organs” Ex:
pinkie toe, appendix, wisdom teeth