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Eric Pianka

Eric Pianka. Karen Bascom Community Ecology Spring 2014. http://uts.cc.utexas.edu/~varanus/eric.html. Who is “The Lizard Man”?. Current Position : Denton A. Cooley Centennial Professor of Zoology, University of Texas-Austin Ecology of Desert Lizards

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Eric Pianka

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  1. Eric Pianka Karen Bascom Community Ecology Spring 2014 http://uts.cc.utexas.edu/~varanus/eric.html

  2. Who is “The Lizard Man”? • Current Position: Denton A. Cooley Centennial Professor of Zoology, University of Texas-Austin • Ecology of Desert Lizards • Research Interests (from his department website): “My interests are ever changing but have included population and community ecology, evolutionary ecology, natural history of desert lizards, resource partitioning, reproductive tactics, foraging theory, allocation, design constraints, thermoregulation, rarity, metapopulations, historical accident and biogeography, species diversity, macrodescriptors, pseudocommunities, phylogenetic systematics, computer simulation of model systems, emergent properties of ecological systems, indirect interactions among populations, disturbance, metapopulations, fire ecology, succession, landscape ecology, and using phylogenies to reconstruct probable ancestral states and deduce the course of evolution.”

  3. Early Life • Born 1939, Siskiyou Co., California • Bazooka explosion injury • (You thought EO Wilson had a cool story) http://uts.cc.utexas.edu/~varanus/bazooka.html

  4. Education and Honors • BA: Carleton College, 1960 • PhD: University of Washington, 1965 • Post-Doctoral Study: Princeton University • Guggenheim Fellow, 1978 • Fellow, American Association for the Advancement of Science, 1981 • Fulbright Senior Research Scholar, Australia, 1990 • D. Sc., (Ecology), University of Western Australia, 1990 • Fellow, Ecological Society of America, 2013.

  5. Text-Wall of Publications

  6. Books http://uts.cc.utexas.edu/~varanus/books.html

  7. Latitudinal Gradients in Species Diversity • Published as a Graduate Student! • In review: • Time • Spatial Heterogeneity • Competition • Predation • Climatic Stability • Productivity Pianka 1966a

  8. On Optimal Use of a Patchy Environment • Pianka’s First “Citation Classic” • Economical choices in food selection • Principle: Energy Gains>Energy Losses • “Optimal Foraging Theory” (OFT) http://en.wikipedia.org/wiki/Robert_MacArthur

  9. Optimal Foraging Theory • “Fine-Grained” Environments • Potential prey items proportionally distributed MacArthur & Pianka 1966

  10. Optimal Foraging Theory • “Patchy” Environments • Potential prey items separated into discrete areas MacArthur & Pianka 1966

  11. Optimal Foraging Theory • Strategies differ between fine-grained and patchy environments • Competition • “Jack of all trades” will outcompete Specialist at low search times • Generalist will outcompete Jack at higher food densities MacArthur & Pianka 1966 http://evhmecology2013.blogspot.com/2013_09_01_archive.html

  12. OFT In Desert Lizards Cnemidophorus “Jack-of-all-Trades” Wide Foraging “Convex” Phrynosoma “Sit and Wait” Specialist Ants Pianka 1966b

  13. Influence of OFT • >1750 Citations • Inspired empirical testing of behavioral ecology • “Convexity, Desert Lizards, and Spatial Heterogeneity” (Pianka 1966b) • Anthropology and Human Evolution • Criticism • How does one measure the “Optimum”? • “Do bumblebees forage optimally, and does it matter?” (Heinrich 1983) • Newer adaptations incorporate other ecological factors Perry & Pianka 1997

  14. Niche Overlap and Diffuse Competition Building on ideas from Elton, Hutchinson, MacArthur and May Pianka 1974

  15. Niche Overlap and Diffuse Competition Niche Overlap Diffuse Competition Total effects of interspecific competitors Strength of inhibition and number of competitors considered • Maximum overlap varies inversely with competition • Does not imply competition • There may actually be less! Pianka 1974

  16. Niche Overlap and Diffuse Competition North America http://uts.cc.utexas.edu/~varanus/herpetol.html Australia http://uts.cc.utexas.edu/~varanus/herpetol.html Africa http://www.hardaker.co.za/challenge-reptiles.htm Desert Lizard Diversity and Density Environmental Variation Trophic, Spatial, and Temporal Niche Dimensions Pianka 1974

  17. Niche Overlap and Diffuse Competition Overlap between pairs decreases, but total overlap in the community increases Pianka 1974

  18. Niche Overlap and Diffuse Competition • Provides empirical support for niche overlap hypothesis • Diffuse effects contribute to maximum overlap more than environmental variables and should be considered in models http://www.studyblue.com/notes/note/n/species-interactions-competition-chapt-11/deck/6283403 Pianka 1974

  19. On r- and K- Selection • Extension of MacArthur and Wilson • Bimodal distribution of generation time • Annual cycles are a possible cause • Body size Pianka 1970

  20. Influence of On r- and K-selection • Perhaps too simplified? • “Physics has friction less hockey pucks, thermodynamics has Carnot engines, and evolutionary ecology has r- and K-selection.” (Mueller 1997) • Transition to age-specific mortality Reznick et al 2002 http://www.nature.com/scitable/knowledge/library/survivorship-curves-16349555

  21. Recent Work • Fire Cycles in Western Australia • Phylogenetics of Varanids and Skinks • Cataloging http://uts.cc.utexas.edu/~varanus/eric.html

  22. Effects of Fire Cycle on Lizards Pianka & Goodyear 2012

  23. He’s Not Dead, Yet!

  24. Works Cited • MacArthur, RH and ER Pianka. 1966. On optimal use of a patchy environment. The American Naturalist 100:603-609. • Perry, G and ER Pianka. 1990. Animal foraging: past, present, and future. Trends in Ecology and Evolution 12:360-364. • Pianka, ER. 1966. Latitudinal gradients in species diversity: A review of concepts. The American Naturalist 100:33-46. • Pianka, ER. 1966. Convexity, desert lizards, and spatial heterogeneity. Ecology 47:1055-1059 • Pianka, ER. 1970. On r- and K-selection. The American Naturalist 104:592-597. • Pianka, ER.1973. The structure of lizard communities. Annual Review of Ecology and Systematics 4:3-74. • Pianka, ER. 1974. Overlap and diffuse competition. Proceedings of the National Academy of Sciences of the United States of America 71:2141-2145. • Pianka, ER and SE Goodyear. 2012. Lizard responses to wildfire in arid interior Australia: Long-term experimental data and commonalities with other studies. Austral Ecology 37:1-11. • Reznik, D, MJ Bryant, and F Bashey. 2002. r- and K-selection revisited: The role of population regulation in life-history evolution. Ecology, 83:1509-1520. • University of Texas-Pianka Webpage. http://uts.cc.utexas.edu/~varanus/Index_to_ERP's_Web_Pages.html

  25. Any Questions? http://uts.cc.utexas.edu/~varanus/eric.html

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