Name: ________________________________
Period: ____
BIOLOGY II: Evolution Exam Study Guide KEY
DATE of Exam: ____________________
Be ready to interpret various graphs and selection curves.
Review the Dr. Darwin article and questions. (I cut this from the unit this semester, disregard!)
1. Explain speciation. The evolutionary process of the creation of new species is known as
SPECIATION
2. What are homologous structures? These are body tissues that are formed from similar tissues but
have been modified for different functions. (Human Leg vs. Horse Leg)
3. What are analogous structures? These structures are similar in appearance and function, but have
different origins. (Bird/Bat/Insect Wings)
4. What are vestigial organs? These are parts of an organism that have little or no apparent purpose
5. What is artificial selection? This is when man selects which organisms to breed, so they are
selecting for traits, rather than nature.
6. What is the difference between stabilizing, directional, and disruptive selection?
Directional Selection:
here the mean value for a
trait shifts in a particular
direction.
Stabilizing Selection:
Normally occurs in an
unchanging
environment.
Disruptive Selection: works
against individuals in the
middle of the spectrum and for
those at the ends.
7. What are some examples of artificial selection? Cows that give more milk, species of dogs, gigantic
crops, etc
8. What ship did Darwin sail on? HMS Beagle
9. Based on the article we read, why don’t scientists believe that dinosaurs flied? (another disregard!)
10. Explain fitness. This is the ability to pass your genes on to the next generation.
11. Where are the Galapagos Islands, and to what country do they belong? 970km off of Ecuador, S.
America. They are part of Ecuador.
12. What was Jean-Baptiste Lamarck’s theory called? Acquired Characteristics
13. Explain Lamarck’s theory. If organisms changed their bodies in certain ways, these changes could
be inherited.
14. Explain Lyell’s theory. This discussed the age of Earth. If the Earth was unchanging and as young
as some people believed, how could you explain erosion, fossils, volcanic eruptions, earthquakes,
etc.
15. How did Thomas Malthus influence Charles Darwin? Malthus wrote about the phenomenon where
more people were being born than dying. Darwin knew some force controlled who survived.
16. Know about Charles Darwin’s book. On the Origin of Species by Means of Natural Selection was
Darwin’s courageous book. It started on the farms of England talking about artificial selection, and
eventually explored natural selection as an evolutionary force. It sold out on the day it was released.
17. What is a gene pool? This is all of the genes of all of the members of a species in a given
population.
18. What was Darwin’s theory that said are all species are descendent from other species? Common
Descent
19. Explain natural selection. This was Darwin’s theory that suggested tiny variations in a population
allow some organisms to survive and reproduce better than others.
20. Know about mutations. Mutations are small changes in DNA. They are usually harmful, and
normally happen at a slow rate. They are a source of variation!
21. Know the following: genes, alleles, loci, gene shuffling, homozygous, and heterozygous.
Genes – DNA sequences that code for traits
Alleles – Different forms of genes (Tall / Short … Brown / Blonde Hair)
Loci – A locus is the chromosomal address of a gene
Gene Shuffling – This is the random mixing of an organism’s genes during sex cell formation
Homozygous – Copies of the same alleles
Heterozygous – Different alleles
22. Explain what variation is and the role it plays in evolution. Variation deals with the often subtle
differences between members of a species. Thanks to this, some organisms will always be better
suited to their environments than others. They will pass along their genes more often, thus changing
(evolving) the species as a whole.
23. What two things lead to genetic variation? Mutations & Gene Shuffling
24. Compare and contrast monogenic and polygenic traits. Monogenic and controlled by one gene and
yield little variation (Pink, Red, White.) Polygenic traits are controlled by two or more genes and
yield a lot of variation (The Vastness of Human Skin Color.)
25. What is meant by reproductive isolation?
This is when members of the same species become so different that mating stops between them.
26. Theoretically, when does natural selection stop? When no variation exists in nature
27. Compare and contrast gradualism and punctuated equilibrium. Gradualism - evolution is normally a
subtle drawn out process of very minor changes taking place over a long period of time
Punctuated Equilibrium - When a rapid change in the otherwise gradual evolution of species occurs
(Eg: Adaptive Radiation)
28. Recall the peppered moth lab! (predator/prey) Natural selection induced by the industrial revolution.
29. Explain genetic drift and give an example. This is the altering of allelic frequencies that results from
chance variation in survival or reproductive success. (Eg: Water snakes in Lake Erie)
30. How does the viceroy butterfly exhibit mimicry? It looks just like the monarch. They are both toxic.
31. Explain adaptive radiation. If the environment changes, as when organisms move to a new one,
evolution may happen very rapidly.
32. What is convergent evolution? This occurs when unrelated species may independently evolve
superficial similarities because of adaptations to similar environments. (analogous structures)
33. What organism of today is probably most similar to the earliest organisms? Bacteria
34. What is the raw material of evolution? Inheritable Variation
35. What is a population? It is a group of members of a species living together.
36. What is Ellis-van Creveld Syndrome? Sufferers have short limbs, malformed hearts, and six fingers
on each hand. Common in the Amish, this was a form of genetic drift known as the founder effect.