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#____ Evolution Unit Objectives
Use this as a guide to what you should understand for this unit.
16.1 Darwin’s Voyage
 What did he notice during his trip to the Galapagos Islands?
Species vary globally – different organisms in similar environment develop similar characteristics
Species vary locally – different organisms in the same environment develop same characteristics
Species vary over time -- evolved

Why were these observations significant? (What did they lead him to conclude?)
They were significant because they helped him develop his theories on evolution, and they aren’t
fixed and they can change over natural processes

What is Pangaea? How does Pangaea support Darwin’s conclusion?
It is a super continent. When there was a super continent, once Pangaea started dividing species
started to vary overtime. All the continents combined together, similar fossil records found in
different continents. This supports the common ancestor theory.
16.2 Ideas that Shaped Darwin’s Thinking
 Hutton and Lyell argued that Earth is millions of years old and continues to change today. What did
Darwin conclude based on Hutton and Lyell’s theory?
Darwin concluded that life changed overtime as Earth changed overtime.

Lamarck hypothesized that an organism could gain or lose a trait during its lifetime by using or not
using certain parts of its body. This acquired characteristic can then be passed on to its offspring. Is
Lamarck’s hypothesis correct? Explain.
It wasn’t correct because organisms don’t strive to become better, and the traits don’t necessarily
pass on to its offspring. But he was the first person to say that organisms change overtime.

What did Malthus predict about unchecked population growth? Explain how his prediction affected
Darwin’s conclusion.
The human population would reduce the resources available. War, famine, and disease. Darwin
realized that Malthus’ theory is the same as organisms. What we learned a long time ago, people and
organisms die, and things adapt. (Limiting factors)
16.3 Darwin Presents His Case
 What are the principles of natural selection?
Struggle for existence - Competition, limited resources
Variations and Adaptations – Help them become “better” to survive and fitness, has to be passed on
to the offspring.
Survival of the fittest – Adaptation, survival (reproduce), person with the most suitable trait.

How does variation occur?
Variation is a random mutation in the DNA

What determines whether or not a characteristic is an adaptation?
Survive and reproduce. If the characteristic is helpful to the survival of the organism.
Physical function also determines the characteristic in a way.

What is “fitness” in evolutionary terms?
Fitness is the rates of survival and reproduction.

What is “survival” in evolutionary terms?
Reproducing and passing on adaptations to the next generation.

Does natural selection act on the genotype or the phenotype of an organism? Explain.
Phenotype, because it gives them the actual physical advantage to reproduce more. From how the
organism looks not necessarily the genotype

What is the principle of common descent?
All species come from a common ancestor.
16.4 Evidence of Evolution
 How does the geographic distribution of species relate to their evolutionary history? (biogeography)
SeungMin – Evolve from ancestors according to different areas they live in, and how natural
selection affects organisms in difference places.
Wendy – “Closely related but different:” related species living in different environments have
different characteristics. “Distantly related but similar” unrelated species living in a similar
environment evolve to have similar characteristics.
Need to know – Selective pressure/environmental pressure/pressure of natural selection

How does the fossil record support evolution? (You may wish to give an example.)
Justin – fossil records support evolution because it shows a step by step process of how animals
develop

Differentiate between homologous and analogous structures. Analogous structures do not provide
any evidence for evolutionary descent. Why not?
Kimberly – homologous structures are present in species with a common ancestor; same structure
but different functions
Michelle – analogous structures of different species have the same functions but different structures
Vincent – analogous structures do not support evolution because they do not show species evolving
from a common ancestor

How does embryology relate to homologous structures?
Geenie – similar patterns of embryological development in different species shows that they may
have a common ancestor
The same parts of the embryo later develop into homologous structures.

How does molecular biology provide evidence of common descent?
Charles – different species have the same molecules with the same functions.
Geenie – i.e. universal genetic code, same nucleotides, same amino acids = a common ancestor
Justin – i.e. same protein synthesis in all organisms
Summary – homologous molecules serving the same functions and with similar amino acid
sequence; genes serving the same purpose; universal genetic code (nucleotides and amino acids)
17.1 Genes and Variation
 Differentiate between allelic frequency (a number) and gene pool (a concept)?

Explain how each of the following leads to genetic variation:
o Mutations
o Genetic recombination in sexual reproduction
o Lateral gene transfer
17.2 p. 490 Genetic Drift
 How does each example of genetic drift affect population diversity? (bottleneck effect, founder
effect)
17.3 Speciation
 What is reproductive isolation?

Name three ways reproductive isolation can develop and give an example of each.
19.2 pp. 550-551 Adaptive Radiation and Convergent Evolution
 What does adaptive radiation assume about recent common ancestry?

What does convergent evolution assume about recent common ancestry?

Briefly differentiate between adaptive radiation and convergent evolution.