Biology 342 Fall 2010
Chris and Megana
Shaw, P.J. Tononi, G., Greenspa, R.J. & Robinso, D.F. (2002) Stress response genes protect against lethal effects of sleep deprivation in Drosophila. Nature 417:287-291.
1. The researchers performed several experiments using both cyc and Hsp83 mutants, however never determined which contributed more to homeostatic sleep. Design an experiment that determines which protein has more of an effect.
2. Relate what we have learned about circadian rhythm to knockouts used in this study. What does it mean to be a timeless, cycle, clock, and period mutant? What are heat shock genes? How might these affect overall behavior?
Andrea and Geoff
Reichard et al (2005) Sexual selection for male dominance reduces opportunities for female mate choice in the European bitterling (Rhodeus sericeus) Molecular Ecology, 14:1533-1542.
1. It has been shown that female choice does not always favor the more dominant males. What benefits could a female receive from mating with a non dominant male, or even a sneaker male? Is the female choice behavior simply an artifact from an ancestral mating system, or are there circumstances where selection for males with more prominent mating displays, rather than simply more dominant males, would be beneficial?
2. As seen in this paper, inter- and intra-sexual selection do not always work in concert. Both modes may create different outcomes or perhaps interact to form more complex dynamics between sexes. What are some of the pros and cons for studying in a lab versus field study when observing these relationships?
Meg and Maria
Laroche, R.K., Kock, A.A., . Dill, L.M. & Oosthuize, W.H.(2008) Running the gauntlet: a predatoreprey game between sharks and two age classes of seals. Animal Behavioru 76: 1901-1917.
1)On page 1903 under Analysis, the researchers make 6 assumptions. Are these assumptions valid? Do they detract from the results? Could you think of a study and/or methods that don't require assumptions like this or that could improve this study?
2)Before reading this paper, what kind of benefit did you think seals would "trade off" (see line one) to reduce their predation risk? How did your reading of the paper change this?
Frank and Rebecca
R.M. Sapolsky and Share, L.J. (2004) A Pacific Culture among Wild Baboons: Its Emergence and Transmission. PlosBiology 4:0534
1. What would you think would cause a comparable shift in human culture? What does this paper say about what causes large-scale cultural change? Does this make you think "change" is more possible?
Neil and Amelia
Auersperga, Gajdona, G.K. and Hubera L., (2010) Kea, Nestor notabilis, produce dynamic relationships between objects in a second-order tool use task. Animal Behaviour 80:783-789.
1. Auersperg, Gajdon, and Huber are attempting to show that kea, non-nest building and non-corvid birds, are capable of second order tool use. They break down the steps necessary to accomplish task 4 and discuss the ways that previous experiments effect present tasks. By breaking down the tasks in this manner, are they truly showing that the Kea are capable of second-order tool use or just that they can be trained to do so? How is that different than learning? What experiments could be further done to explore this?
2. The sample size is constantly changing. Gino dies and Plume and Ry are taken out of an early experiment (task three) and not allowed to participate in task three. How would this effect the data? Is the reduced sample size important? Is this a manipulation of the data or is it justified?
3. In this small sample size there appear to be a sex bias. As previously stated two of the three females were removed from the study because they were not able to complete a task. Luke is often mentioned as a high performer. How could sex play a role in these tasks? What other aspects of the study could have differentiated the birds ability to perform? Is it necessary to look at these aspects when doing an experiment?
Quinn and Katheryn
The authors present two hypotheses to explain how complex cognitive abilities evolved: the social intelligence hypothesis and the technical intelligence hypothesis. What are these two hypotheses and how might they work in tandem to drive evolution of intelligence?
In the discussion of pair bonding and family structure, the researchers mentioned that they used observations at feeding tables and radiotracking data to determine if mated pairs of New Caledonian crows remained together throughout the year. How might these observations have overestimated or underestimated the time that the pairs remained together? What other observations could be performed to give a more accurate account of the time a couple spends together?
Amber Bang and Esther Ladizinsky
Romer H, Lang A, Hartbauer M (2010) The Signaller's Dilemma: A Cost–Benefit Analysis of Public and Private Communication. PLoS ONE 5(10): e13325. doi:10.1371/journal.pone.0013325
It's confusing that, athough the adaptive value of tremulations is consdiered to be a defense against bat predation during the full moon, the bats are not very active during the full moon. Assuming that the selective pressure leading to this bimodal communication system was in fact bat predation, it is interesting to consider the possibility that evasive behavior katydids placed pressure on the bat's hunting stragetgy (o.e. aboiding the full moon). However, if bat predation was not the selective force driving this behavior what might its phylogenetic history be and how might it be adaptive in its current form? Povide Gould and Lewontin potential response to the above line of logic and give your own response.
Do you think the bats reduced their foraging during nights of high nocturnal light levels due to their own need to be less detectable by their predators?
Lindsey and Emily Z.
Vacha, M., Kvícalova, M., & Puzova, T. (2009)Radio frequency magnetic fields disrupt magnetoreception in American cockroac. J. Exp Biol .212, 3473-3477.
1. In their discussion, Vacha et al. (2008) admit that "the magnet response used describes a degree of activity rather than orientation. For that reason it cannot be generalized with certainty that the RF field disrupts insect magnetic orientation". Does this observation, plus their results, convince you that cockroaches are sensitive to changes in the magnetic field? Why or why not?
2. Consider the adaptive value of magnetoreception in cockroaches. Why might this have evolved? Birds have long been known to be sensitive to Earth's magnetic field. We know this aids their navigational abilities. Additionally, Begall et al. 2008 found that grazing cattle align themselves by the magnetic poles. Why might magnetoreception have evolved convergently in such a diversity of species?
Lisa and Briana
Rotjan et al. 2010. Social context of shell acquisition in Coenobita clypeatus hermit crabs. Behavioral Ecology 21:639-646.
1. For each laboratory trial, the total number of behaviors recorded during a sampling session was divided by the number of crabs present to give an average behavioral measure. Considering the small sample size for the authors' laboratory experiments, how much sense does it make to distribute behavior equally among individuals? Do you think it is important in this context to take individual preference, learning, and life history into account rather than assuming all crabs are the same? In a broader sense, how much individuality can we ascribe to animals, and how does this affect how we study them?
2. Would you classify the behaviors involved in the formation of synchronous waiting chains (piggybacking, waiting) as cooperative? Why or why not?
Michelle and Genevra
Anderson, D.J., Porter, E.T., & Ferree, .D. (2004) Non-Breeding Nazca Boobies (Sula granti) Show Social and Sexual Interest in Chicks: Behavioural and Ecological Aspects Behaviour 141:959-977.
1) The reason as to why Nazca Boobies display NAV behavior is yet unknown, though the article brings up several hypotheses. What are some other hypotheses that can explain this behavior?
2) While factors such as age, sex, amount of rain and time of year were examined in this study, are there any other factors that should have been examined that could result in either the vampirism or NAV behaviors?
Katrina Getz and Michael Turvey
Rafal Kowalczyk & Andrzej Zalewski. "Adaptation to cold and predation—shelter use by invasive raccoon dogs Nyctereutes procyonoides in Bia?owieza Primeval Forest (Poland)." European Journal of Wildlife Research, June 2010 (online edition).
1. The authors propose several different adaptive value hypotheses concerning the reasons behind burrow selection. Are any of them questionable? Why? In light of our discussion on the adaptionist programme, is it reasonable to assume that raccoon dog burrow choice is based primarily on its adaptive value, or could it be because of the raccoon dogs' underlying neural plasticity? How could you test this?
2. What costs might arise if an individual raccoon did not vary its burrow type and location, and could any one type of shelter be considered the "safest" shelter? Why? How do the authors define a shelter safety, and what problems does this present (especially considering raccoon dogs' preference for badger setts as breeding sites)? Can you propose a better means of determining the safe-ness of a particular shelter?
3. The raccoon dog is an invasive species from Asia. Why might it be important to conduct research on such a species? Why might their presence in the Bialowieza Primeval Forest be problematic? Could they possible benefit the conservation efforts and biodiversity of the forest? (Note: the forest is a UNESCO World Heritage Site and one of the last remaining old growth forests in Europe. Source: http://bp21.org.by/en/books/savepol.html)
Nate and Zina
Levey, Londoño, Ungvari-Martin, Hiersoux, Jankowski, Poulsen, Stracey, &. Robinson (2009) Urban mockingbirds quickly learn to identify individual humans PNAS 106: 8959-8962
1. The data collected in this experiment are about mockingbirds incubating eggs. The average reported incubation time is 12 -14 days with clutch of 2 ? 6 eggs. Would you expect the birds to be more or less likely to wait till the last moment to flush at the beginning of incubation or towards the end? Do you think the bird would alter the distance at which it flew away from its nest depending on how many eggs there were?
Miska and Matt
T. H. Clutton-Brock, TH, O'Riain, MJ, Brotherton,PNM. et al (1999) Selfish Sentinels in Cooperative Mammal. Science 284:1640.
Why would sentinels spend less share of time guarding in a raised stance position when they're in smaller groups, but increase as the group size increases then fall down again when it is much bigger? Don't they have to spend more time guarding because they can't rotate the role? Or do they risk not having any sentinels for the sake of foraging? [Look at Figure 4.C]
If the sentinels were on average the same distance away from safe-holes as foragers, would the benefit for sentinels be less? Why are the sentinels only 1.7 meters away from safe-holes? Why not 1 meter?
Why do meerkats maintain the role of the sentinel when there's no pressure to maintain the behavior, i.e. kin selection or deferred benefits?