Sample questions for Honors
Seminar, “Rare Earth”
mid-term exam
- Recent studies have shown that extremophiles
have a wider range of habitats than previously appreciated. How wide is
this range, and what does it imply for life on other bodies in our solar system?
- How long did it take for large, multicellular
animals to develop after the formation of the Earth? If this amount of time is typical for
star systems throughout the galaxy, what restrictions does it place
on the types of stars that could host planets with high life?
- In general prokaryotes have a wider range of habitats
than do eukaryotes. Why is this, and what features of the eukaryotes make
this true?
- Other than providing oxygen for us, the Earth’s atmosphere furnishes
a number of environmental “services”, that is physical processes that make
higher life possible on the surface of the Earth. Atmospheres of other planets throughout
the galaxy would have to do the same thing if higher life is to exist
there. Name and describe some of these atmospheric “services”.
- What kinds of evidence reveal when eukaryotes
evolved? If the actual date differs by up to half a million years from the
commonly given date, what does this imply about the ease or difficulty of
complex life forming?
- Astronomers believe that the relative abundance of
elements heavier than hydrogen and helium (the so-called “metals”) has
been steadily increasing throughout the history of the universe. Why is this “increasing metallicity” important for the discussion of life
elsewhere in the universe. Why
might it suggest the possibility of an “optimum age” for the existence of life?
- Which feature or features of a planet are most
important for determining whether that planet is habitable, and why?
- Discuss some of the very recent findings of the Mars
Exploration Rovers (“Spirit” and “Opportunity”) which are
relevant to exobiology.
- What steps needed to occur for life to form
originally? For one of these steps discuss the difficulties in surmounting
that requirement.
- Discuss what is meant by the term “impact frustration” of early
life. Why does the significance of
this concept depend on exactly when life originated on the early Earth?
- Is it likely that the Cambrian Explosion is only an artefact of the preservation of fossils? Why or why
not?
- Describe a way in which the atmosphere of the Earth
differs from a “typical” terrestrial planet, either in our solar system or
other star systems. How did it get this way?
- Discuss a way or ways in which plate tectonics may
have played a role in the origin and evolution of life on Earth.