This morning, my mineralogy had a discussion about a January 2011 Geology paper by Paasche & Lovlie on the “Synchronized postglacial colonization by magnetotactic bacteria.” In general, the paper was voted ‘more enjoyable’ than last week’s possible impact structure paper.
The questions I asked the students to consider and submit answers to:
- what are MTBs?
- what is the primary question the authors are trying to address?
- what kind of data did the authors use?
- would this kind of study work in MN? How would you choose your lakes?
- to support the “bird repopulated the MTB” theory, what kind of study do you think might help?
- terms you didn’t understand?
- concepts that were hard to grasp?
My students believe that in order to test the “bird repopulation” theory proposed by the authors two experiments should be run: 1) force-feed magnetotactic bacteria to birds & see if the bacteria can be recognized in the bird poop and 2) track appropriate bird migration patterns near receding glaciers.
A number of the students highlighted the ARM / SIRM ratio as a term / concept that they could not either understand or find understandable material on when they searched the web. I will admit that the paper just assumed the readers knew the difference between anhysteretic remanent magnetization (ARM) and saturation isothermal remanent magnetization (SIRM). And the best site I could find searching quickly this morning was much more scientific than students without geophysics were going to grasp. These are the days I wish Chris had written a post that I could simply point the students towards…
The other question that came up that I couldn’t answer was about how to magnetotactic bacteria actually produce magnetite. If anyone has a good link, I would appreciate it–my biology background is limited to 9th grade & one semester of paleo in German!
Full citation for the paper (which is behind a paywall):
Paasche, O. and Lovlie, R., 2011, Synchronized postglacial colonization by magnetotactic bacteria: Geology, v. 39, p. 75-78.