For this first assignment, you are to read one of the papers below about a possible evolutionary adaptation and then answer the following questions pertaining to your paper. Number your answers.
Which article did you read? Copy and paste the full citation of your paper for your answer #1.
Explain how the attribute discussed in your article is or is not heritable. Heritability is required for a trait to be an adaptation. A trait is heritable if it has a genetic basis in an organism’s DNA and can be passed on from one generation to the next, like eye color, face shape, height, etc. This is one criterion a trait must pass for it to be considered an adaptation. If the authors have not demonstrated this point, then it is a hypothesis that must be tested in future research.
Explain how the attribute discussed in your article does or does not confer an advantage in survival or reproduction by enabling an individual to resist, or to respond to, an environmental agency (e.g., fire, flood, storms, freezing temperatures) or biological agent (e.g., predators, competitors, dangerous prey, fickle mates) that could in principle kill the individual or cause it not to reproduce. Competitors and potential mates can also be selective agents. A selective agent is any kind of biological entity that is capable of preventing survival and/or reproduction of individuals or entire groups of individuals. An agency is any kind of non-biological entity (like hurricanes, cold weather, asteroid impacts, etc.) that does the same thing. Do not overlook the fact that advantage means advantage for an individual (natural or sexual selection) OR advantage for a group (group selection). Either is sufficient to cause adaptive evolution.
Explain how or how not the agency or agent in question is a real threat to individuals. For modern humans like yourself, tigers are a potential selective agent, because they can eat you. But tigers are not a real threat to human populations in the U.S., because they are housed in zoos and are rare even then. In other words, tigers cannot cause human populations in the U.S. to evolve, because they are not running loose in large numbers causing selective survival or reproduction. Tigers are unimportant agents of selection. For a trait to be an adaptation, the agent must be real and important by causing sufficient deaths or preventing reproduction often enough to alter the composition of the next generation beyond random variation.
What additional evidence or alternative hypotheses you would like to see or propose to explain the attribute in question?
Papers to choose from:
Buttresses (greatly expanded bases) in tropical rain-forest trees. A. P. Smith, 1972, Buttressing of tropical trees: a descriptive model and new hypotheses. American Naturalist 106: 32-46. https://www.journals.uchicago.edu/doi/abs/10.1086/282749Links to an external site.
Ritualistic fighting. Pennisi, E., 2012. In battle – fighting rituals. Science 336:838-839. https://www.science.org/doi/full/10.1126/science.336.6083.838?adobe_mc=MCMID%3D04000694648767407835405683999528768606%7CMCORGID%3D242B6472541199F70A4C98A6%2540AdobeOrg%7CTS%3D1716249600Links to an external site.
Adaptive origin of hiccups. Straus, C., et al., 2003. A phylogenetic hypothesis for the origin of hiccough. Bioessays, 25(2), pp.182-188. https://onlinelibrary.wiley.com/doi/abs/10.1002/bies.10224?casa_token=MOb3SKyTqX8AAAAA%3Al1Kfx1Pa1wLsXKeyw6EQDwW7Az71s0skpbuTBh3J1yzzcUGWm18N2l2YIgG3Mjr4gRfmju-28MKuiwLinks to an external site.
Having a “false head” near the posterior end of the body in butterflies. R. K. Robbins, 1981, The “false head” hypothesis: predation and wing pattern variation of lycaenid butterflies. American Naturalist 118: 779-785. https://www.journals.uchicago.edu/doi/abs/10.1086/283868Links to an external site.
Long lifespan in killer whales. A. Foster et al., 2012. Adaptive prolonged postreproductive life span in Killer Whales. Science 337:1313. https://www.science.org/doi/full/10.1126/science.1224198?casa_token=gzgUH1EigToAAAAA%3Aearfrm5xm177-LXwf5jezVeBnLWzVbig3STk4b4xP1Sa-P7_blQEfY2n31u2ccu_sme2MBh5s_5SLinks to an external site.