Dionaea Muscipula and Natural Selection By Nancy Tang and Celia Gurney

Our Question and Hypothesis How did evolution by natural selection lead to Dionaea muscipula becoming carnivorous? There was genetic variation within the Dionaea muscipula population. Over time, members of the population with traits that aided in catching and digesting insects had more reproductive success than those that lacked such traits. Over time, the alleles for carnivory became fixed.

Experiments Karagatzides and Ellison (2009) found that leaves cost more energy to produce than trapping mechanisms, but trapping mechanisms produce less energy from photosynthesis. Cameron et al. (2002) used DNA analysis to hypothesize which type of carnivorous plant the Dionaea muscipula evolved from.

The trapping mechanism

Dionaea’s Ancestor?

What we know about Dionaea’s evolution Darwin hypothesized that natural variation among plant species led to certain plants having sticky glands that also had digestive capabilities (Albert et al., 1992). A parsimony analysis by Albert, Williams, and Chase (1992) suggests that carnivory evolved at least six separate times within the angiosperm monophyletic group.

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Further Research Questions Which traits that aid in carnivory evolved first? Was it the sticky glands? Digestive capabilities? Which parts of their insect victims are the most useful to plants?

References Albert, V. A., Williams, S. E., & Chase, M. W. (1992). Carnivorous plants: Phylogeny and structural evolution. Science, 257(5076), 1491-1495. Cameron, K. M., Wurdack, K. J., & Jobson, R. W., (2002). Molecular evidence for the common origin of snap-traps among carnivorous plants. American Journal of Botany, 89(9), 1503-1509. Ellison, A. M., Gotelli, N. J., (2008). Energetics and the evolution of carnivorous plants—Darwin’s ‘most wonderful plants in the world’. Journal of Experimental Botany, 60(1), 19-42. Forterre, Y., Skothelm, J., M., Dumals, J., & Mahadevan, L. (2005). How the Venus flytrap snaps. Nature, 433, 421-425. Gibson, T. C., & Waller, D. M., (2009). Evolving Darwin’s ‘most wonderful’ plant: Ecological steps to a snap-trap. New Phytologist, 183, 575-587. Karagatzides, J. D., & Ellison, A. M., (2009). Construction costs, payback times, and the leaf economics of carnivorous plants. American Journal of Botany, 96(9), 1612-1619. Williams, S. E. (1975). Comparative sensory physiology of the droseraceae—the evolution of a plant sensory system. American Philosophical Society, 120(3), 187-204.