Bio 105 Study Guide for Final Exam on December 19, 2013
This study guide covers material since exam 3. The three previous study guides provide
coverage for material from the remainder of the semester. The final exam will consist of 75
questions with approximately ½ on material since exam 3 and ½ on material from the first two
thirds of course material.
I. Darwin and the Theory of Evolution
Explain how evolution is important in most disciplines of biology.
• Nearly all facts of biology are directly related to evolution
How did people explain why there were so many different living things on earth before
• A perfect and complete system created with no need for change (no evolution)
• Ladder of life:
◦ Other organisms
Darwin came up with an alternative explanation?
• Closely related species evolved from common ancestors
• Mechanism of evolution is natural selection
What were some of the ways that accepted concepts of the order of nature were
challenged by other scientific evidence before Darwin’s theory?
• Copernicus- earth not the center of he universe
• Matter made if more than earth, water, fire and air
• Fossils- signs of previous life
• Geology- the earth is billions of years old
• Characteristics could be inherited
Where did Darwin come up with most of the data that shaped his formulation of his theory?
• HMS Beagle?
What were four of Darwin’s major observations? Explain each.
1. Populations have the potential to increase exponentially
2. Populations are fairly constant in size
3. Natural resources are limited
4. There is a variation within a species and variation is limited
What were three of Darwin’s major deductions?
1. Only some individuals in a population survive
2. Individuals with favorable variations are more likely to survive and reproduce
3. Accumulation of variation over many generation is evolution
Describe each, including natural selection.
• Natural selection:
◦ The fastest rabbits are eaten less often by foxes
◦ The fastest foxes catch more rabbits ◦ The most colorful bird attracts the most females for mating
◦ Natural selection changes a species over time
◦ Gradual separation of populations over time
◦ May proceed to the point where there are two different forms (species)
List and describe evidence gathered since Darwin that supports his theory of evolution.
• Selective factors:
◦ Traits can be selected for, wither in nature or by humans
◦ Many organisms have a fossil record that illustrates their history
◦ Evolution of horse
▪ 60 million years ago; fox sized, forest browser with four toes
▪ Gradual increase in size, teeth for grazing, reduction in # of toes
• Homologous and analogous structures
▪ Structurally similar but may be very different functionally
▪ Forelimbs of birds, reptiles, bats, humans similar structure
▪ Evidence of evolution from a common ancestor
▪ Similar form and function, but may be very different structurally
▪ Evidence of selection on existing structures
▪ Moth, dinosaur, bird, at all have wings
• Biological chemistry (proteins and DNA)
◦ There are thousands of proteins that are similar among animals
◦ Most proteins in humans share 60-80% of amino acids
◦ Evolutionary relationships evident in more then visual similarities (genetic
level- DNA and resulting proteins)
How has information gathered through the study of biological chemistry added to the
theory of evolution?
• Evolutionary relationships evident in more than visual similarities (genetic level-
DNA and resulting proteins)
What is speciation?
• Existing species gives rise to new species
What is required for speciation to occur?
• Geographic opportunity- overcome physical barriers to reach new location
• Physiological opportunity- physical environment must be tolerable
• Ecological opportunity- available niche
What are allopatric, sympatric and parapatric speciation?
◦ Occurs between isolated populations
• Parapatric- ◦ Occurs between adjacent populations
◦ Little mixing between the two
◦ Occurs between populations that overlap
◦ Other factors isolate segments of population
◦ Some type of reproductive isolation necessary
Describe adaptive radiation in Hawaiian honeycreepers and in Galapagos finches.
• Hawaiian Honeycreepers
◦ Original founder species radiates into many new species
▪ Hawaii very isolated
▪ Early finch colonizer reaches new islands
▪ Environmental conditions of new habitat act as selective factors
▪ Some survive and adapt to new conditions
▪ Hawaiian populations isolated from original population
▪ Interbreeding restricted
▪ A new species arises that does not or cannot interbreed with original
• Galapagos Islands- Darwin's Finches
◦ Original colonizing finch population- adaptive radiation into 13 different
◦ Selection pressure- food
◦ Different beaks for feeding on different food
What is convergent evolution?
• Similar selection pressures on different types of organisms
• Common patterns (solutions for survival) repeated
• Unrelated species evolve similar (analogous) adaptive characteristics
◦ Example: shark and dolphin fins
What is divergent evolution?
• Closely related species become more and more different
• Ex: ancestral horse gave rise not only to current horses, but also zebras, etc
• Extreme examples are adaptive radiation- Hawaiian honeycreepers and Galapagos
• Ancestral species diverges into 2 or 3 new species
What is co-evolution?