Mr. Blacher’s 7th Grade Life Science

My Study Guide for: Evolution

Chapter 7/8

I.  Vocabulary:

1.Species / 8. Selection
2.Adaptations / 9. Continental Drift
3. Evolution / 10. Theory
4. Natural Selection / 11. Law
5. Overproduction / 12. Fossil (Absolute and Relative Dating)
6. Competition / 13. Sedimentary
7. Variation / 14. Homologous Structures

II.  Charles Darwin:

·  Who was this guy and what did he observe in the Galapagos Islands?

·  What did he learn from the finches of the Galapagos?

·  How did he explain what he saw?

III.  Natural Selection

·  What is it?

·  What are the four factors that influence this process?

·  How does it lead to evolution ?

·  What happened to the peppered moths during the Industrial Revolution? How does this illustrate natural selection?

IV.  Evolution

·  What is the role of genetics in this process?

·  How can new species arise (Geographic isolation, AKA-allopatric speciation)?

·  What evidence is there for evolution (DNA, homologous structures, similarities in embryonic (pre-birth) development)?

·  Phylogenetic (branching) tree diagrams…what do they show?

V.  Fossils and the Fossil Record

·  What are petrified fossils, molds, casts, and preserved remains?

·  How can we tell how old fossils are (relative and absolute dating methods)?

·  What is half-life and how do we use it to date rocks and fossils?

·  What is the key to effective selection of isotopes for radiometric dating?

·  What is the geologic time scale?

·  How old is the Earth?

VI.  How long does Evolution take?

·  What is Gradualism?

·  What is Punctuated Equilibrium?

Practice Questions:

1.  During the Great Migration in the Serengeti, many of the grazing herbivores don’t survive…many do. Use what you know about natural selection to explain what is taking place. Can you think of another situation in the natural world wherein this takes place?

2.  How do genetics, natural selection, and evolution all interrelate?

3.  There are 10 grams of carbon-14 in a rock at time=zero. How much time will have passed, and how much carbon-14 will remain in the rock after three half-lives?

4.  You have found a fossil of a trilobite, which is an extinct arthropod that first appeared in the Cambrian period (this period ended about 488 mya). You may borrow the equipment to measure Carbon-14/Nitrogen or the equipment to measure Uranium-235/Lead-207. Which equipment would you borrow to attempt to date this fossil and why?