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Full-Text Articles in Ecology and Evolutionary Biology
Growth And The Expression Of Alternative Life Cycles In The Salamander Ambystoma Talpoideum (Caudata: Ambystomatidae), Travis Ryan, Raymond Semlitsch
Growth And The Expression Of Alternative Life Cycles In The Salamander Ambystoma Talpoideum (Caudata: Ambystomatidae), Travis Ryan, Raymond Semlitsch
Travis J. Ryan
Complex life cycles (CLCs) contain larval and adult phases that are morphologically and ecologically distinct. Simple life cycles (SLCs) have evolved from CLCs repeatedly in a wide variety of lineages but the processes that may underlie the transition have rarely been identified or investigated experimentally. We examined the influence of larval growth rate on the facultative expression of alternative life cycles (metamorphosis or maturation as gill-bearing adults [= paedomorphosis]) in the salamander Ambystoma talpoideum. We manipulated growth rates by altering the amount of food individuals received throughout larval development. The expression of alternative life cycles in A. talpoideum is influenced …
Accuracy And Efficiency Of Algorithms For The Demarcation Of Bacterial Ecotypes From Dna Sequence Data, Juan Carlos Francisco, Frederick M. Cohan, Danny Krizanc
Accuracy And Efficiency Of Algorithms For The Demarcation Of Bacterial Ecotypes From Dna Sequence Data, Juan Carlos Francisco, Frederick M. Cohan, Danny Krizanc
Frederick M. Cohan
Identification of closely related, ecologically distinct populations of bacteria would benefit microbiologists working in many fields including systematics, epidemiology and biotechnology. Several laboratories have recently developed algorithms aimed at demarcating such ‘ecotypes’. We examine the ability of four of these algorithms to correctly identify ecotypes from sequence data. We tested the algorithms on synthetic sequences, with known history and habitat associations, generated under the stable ecotype model and on data from Bacillus strains isolated from Death Valley where previous work has confirmed the existence of multiple ecotypes. We found that one of the algorithms (ecotype simulation) performs significantly better than …
Hydroperiod And Metamorphosis In The Small-Mouthed Salamander
Hydroperiod And Metamorphosis In The Small-Mouthed Salamander
Travis J. Ryan
Legacy Of Land Use In Southern Appalachian Forests: Effects On Terrestrial Salamander Abundance Along Edges And Within Abandoned Logging Roads, R. Semlitsch,, Travis Ryan, M. Chatfield, B. Drehman, K. Hamed, N. Pekarek, M. Spath
Legacy Of Land Use In Southern Appalachian Forests: Effects On Terrestrial Salamander Abundance Along Edges And Within Abandoned Logging Roads, R. Semlitsch,, Travis Ryan, M. Chatfield, B. Drehman, K. Hamed, N. Pekarek, M. Spath
Travis J. Ryan
Presence And Colonization Of Placobdella On Two Species Of Freshwater Turtles (Graptemys Geographica And Sternotherus Odoratus), Travis Ryan
Travis J. Ryan
It is generally accepted that bottom-dwelling turtles have a higher ectoparasite load than turtles that bask aerially because of effects of desiccation on ectoparasites, especially with regard to leeches. We compared number of leeches (primarily Placobdella parasitica) on field-caught Common Musk Turtles (Stemotherus odoratus) and Common Map Turtles (Graptemys geographica). The bottom-dwelling species S. odoratus had more than 20 times the number of leeches than the aerial-basking species G. geographica. We then exposed cleaned (leech-free) turtles to leeches in mesocosms (cattle tanks) to measure the rate of colonization. In this experiment, S. odoratus had more than four times the number …