Study Guide for Change Over Time and Adaptations- Chapter 12

Name ______Date ______Bk _____ #__

-In the table below identify who said what. (Darwin, Lamarck or both)

Concept / Idea Darwin, Lamarck or Both

There is variation within a species / Darwin
Organisms can only pass on traits they are born with / Darwin
The environment had something to do with why organisms changed / Both
Parents can pass on changes made in their lifetime to their offspring / Lamarck
Organisms change because they want to survive. / Lamarck
Organisms cannot become extinct. / Lamarck
Parents can pass on at least some of their traits to their offspring. / Both
Certain traits helped organisms survive better than organism without those traits. / Darwin
Species are still changing today. / Both
Natural Selection / Darwin
Acquired Characteristics / Lamarck
Species have changed over time. / Both

Define the vocabulary words from Chapter 12 section 1 in the textbook.

1. Species- a group of organisms that share similar characteristics & can reproduce among themselves to produce fertile offspring

2. Evolution- change in inherited characteristics over time

3. Natural Selection- organisms with traits best suited to their environment are more likely to survive and reproduce

4. Variation- inherited trait that makes an individual different from other members of its species

5. Adaptation- any variation that makes an organism better suited to its environment

6. Gradualism- describes evolution as a slow process by which one species changes into a new species through a continuing series of mutations and variations over time

7. Punctuated Equilibrium- describes the rapid evolution that occurs when a mutation of a few genes results in a species suddenly changing into a new species

On reason giraffes have long necks is so that they can reach the food high in the tree top canopy. Explain how the giraffes got their long necks according to Darwin and then how would Lamarck explain their long necks.

Darwin’s Explanation / Lamarck’s Explanation
There is variation in the giraffe population so some giraffes have longer necks and some have shorter necks. The individuals better suited to reach the food with their longer necks are more likely to survive & reproduce than the giraffes with the shorter necks.
“SURVIVAL OF THE FITTEST” / The giraffes that could not reach the high tops of trees would simply stretch their necks to reach the food. They would pass on their newly developed stretched neck to their babies.
(This theory is UNTRUE!)

Look back at the packet of notes on adaptations and list and provide an example of the 4 factors that drive natural selection. (Think back to the turtles)

Factor of Natural Selection / Example
Overproduction / A mature oak tree drops hundreds of acorns and only a few will develop into an adult tree
Competition / Bighorn rams fight each other for mating rights
Variation / The peppered moths can exist in a variety of colors, from light to dark and in between
Selection / The forest changed to a darker color from the soot, which was better for the darker moths. The environment “SELECTED” the darker moths to survive because they were better adapted!