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Biology 11
Name:
Evolution Assignment
1.
State the theory of evolution.
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2.
All life on earth has changed over time
Modern organism have descended from ancient ones
Parents pass on genetic information to offspring with changes (Decent with
modifications)
What does the term “common decent” mean?
The theory that all life comes from one common ancestor
3.
What role does adaptation play in “fitness” and speciation?
Organisms that have favourable adaptations increase their fitness (ability to reproduce
and survive). This may lead to speciation if there is enough genetic change between
popoulations (reproduction isolation has to occur)
4.
How would the concept of Natural Selection be linked to that of survival of the
fittest? Use examples to explain your answer
The organism that is best suited (fit) to its niche will be better equipped to survive the
environmental pressures of the area. Ie) Nature selects this organism for survival
Biology 11
5.
Name:
Describe, in detail, how mutations in genes can contribute to evolution.
Gene mutations can lead to different proteins being made OR prevent the protein from
being made. This change in protein production can have either a positive, neutral or
negative effect on the organism. If these changes are favoured they will be continued to
be selected for. This may lead to an increase in the frequency of the allele for the given
gene.
6.
What is speciation?
The development of a new species. This new species is unable to create fertile offspring
with its original species. Reproduction isolation needs to exist for the populations to
diverge into separate species
7.
How is punctuated equilibrium related to adaptive radiation? Use examples
Punctuated equilibrium is a long period of no change interrupted but rapid change. This
is usually due to some major event.
Adaptive radiation is where one central area supports a population but rapid changes
occur due to the recent availability of resources. This population migrates into new
environment with different niches. This original population adapts/ evolves to suit the
new niche. With reproductive isolation, the original population is now multiple species
Ex) the Galapagos finches…migrate to different islands
Biology 11
8.
Name:
Explain what convergent evolution is and give evidence.
Where two different species evolve similar structures to do the same job. Their
environments (niches) are similar enough to select for similar traits. Analogous
structures illustrate this. They do the same job (have similar appearance and
function) but arose from different internal structures. E.g. wings of the bat, insect
and bird.
9.
Explain what divergent evolution is and give evidence.
One population moves in order to survive by exploiting different niches. They
change from a common ancestor to develop new functions from similar structures
10.
Describe each of the following agents of evolution (give examples if possible).
a.
Genetic Drift
The change in the frequency of alleles due to random sampling
b.
Gene Flow
The introduction of an allele into a new population of the same species
c.
Non-random mating
Mates that favour a specific trait. The trait will likely show more in the next
generations
11.
Compare and contrast Gradualism and Punctuated equilibrium
Biology 11
Name:
Gradualism - Slow, gradual change. E.g. The tiger stripe.
Punctuated equilibrium - Rapid change follows periods of no change.
Set in motion when small population becomes isolated from larger
group or migrates to a new site or catastrophe opens up niches
previously occupied. Less competition allows the natural variation
within the population to fit in and become more adapted to a
particular niche by natural selection. E.g. Darwin’s finches of the
Galapogus Islands.
12.
Diversity, in biology, means different species. Do you believe that evolution
increases diversity? Explain why or why not using what you have learned so far.
Answers will vary depending on what you believe and what ideas you have formed
throughout his unit.
Diversity is the number of different organisms present in an ecosystem, it can also
be the differences in a specific population of the same species which take into
account different versions of the same allele/gene, which cause organisms to look
different but still able to produce fertile offspring.