Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Theory of Island Biogeography

Statistical method for testing the neutral mutation hypothesis by DNA polymorphism.

An essential textbook for any student or researcher in biology needing to design experiments, sample programs or analyse the resulting data The text begins with a revision of estimation and hypothesis testing methods, covering both classical and Bayesian philosophies, before advancing to the analysis of linear and generalized linear models Topics covered include linear and logistic regression, simple and complex ANOVA models (for factorial, nested, block, split-plot and repeated measures and covariance designs), and log-linear models Multivariate techniques, including classification and ordination, are then introduced Special emphasis is placed on checking assumptions, exploratory data analysis and presentation of results The main analyses are illustrated with many examples from published papers and there is an extensive reference list to both the statistical and biological literature The book is supported by a website that provides all data sets, questions for each chapter and links to software

/pdf/experimental-design-and-data-analysis-for-biologists-8ybva8d53x.pdf

Experimental Design and Data Analysis for Biologists

Ecological changes in the phenology and distribution of plants and animals are occurring in all well-studied marine, freshwater, and terrestrial groups These observed changes are heavily biased in the directions predicted from global warming and have been linked to local or regional climate change through correlations between climate and biological variation, field and laboratory experiments, and physiological research Range-restricted species, particularly polar and mountaintop species, show severe range contractions and have been the first groups in which entire species have gone extinct due to recent climate change Tropical coral reefs and amphibians have been most negatively affected Predator-prey and plant-insect interactions have been disrupted when interacting species have responded differently to warming Evolutionary adaptations to warmer conditions have occurred in the interiors of species’ ranges, and resource use and dispersal have evolved rapidly at expanding range margins Observed genetic shifts modulate local effects of climate change, but there is little evidence that they will mitigate negative effects at the species level

https://www.fws.gov/southwest/es/documents/R2ES/LitCited/LPC_2012/Parmesan_2006.pdf

Ecological and Evolutionary Responses to Recent Climate Change

The degree of herbivory and the effectiveness of defense varies widely among plant species. Resource availability in the environment is proposed as the major determinant of both the amount and type of plant defense. When resource are limited, plants with inherently slow growth are favored over those with fast growth rates; slow rates in turn favor large investments in antiherbivore defenses. Leaf lifetime, also determined by resource availability, affects the relative advantages of defenses with different turnover rates. Relative limitation of different resources also constrains the types of defenses. The proposals are compared with other theories on the evolution of plant defenses.

https://science.sciencemag.org/content/sci/230/4728/895.full.pdf

Resource Availability and Plant Antiherbivore Defense

Larvae of 9 species of swallowtail butterflies (Papilionidae), 10 species of bombycoid moths (Saturniidae and Bombycidae), and of the southern armyworm (Noctuidae: Spodoptera eri- dania) were reared under standardized conditions on mature leaves of many of their typical food plants. Growth rates, feeding rates and efficiencies of food and nitrogen utilization of larvae in their penultimate and final instars were measured by standard techniques. The study revealed a clear relationship between larval growth and growth form of the food plants quantified as leaf water content. Larvae grew faster and more efficiently on herbaceous plants than on the foliage of shrubs and trees. These differences were greater than could be accounted for by variation in the degree of feeding specialization among the insect species tested. The particular leaf characteristics responsible for the relationship between plant growth form and larval growth are not known, but they probably include leaf water content, nitrogen content, tough- ness, and fiber content. Since trees are likely to be more apparent to enemies than are most herbaceous plants, our results are consistent with recent suggestions that the mature foliage of apparent plants is generally poorer food for herbivores than is the foliage of unapparent plants. However, the extent to which the low food value of mature tree leaves is actually a consequence of the selective action of herbivores remains an open question.

https://www.jstor.org/stable/pdfplus/1936618.pdf

Growth of Herbivorous Caterpillars in Relation to Feeding Specialization and to the Growth Form of Their Food Plants

Papilio canadensis encounters shorter, cooler summers in interior Alaska than in northern Michigan: average thermal sums are 583 vs. 985 Celsius degree—days (10°C base); mean daily temperature is 14.4 vs. 18.8°. The temperature physiology of P. canadensis could be evolutionarily conserved, or the species may be a composite of regionally adapted populations. We evaluated these hypotheses by comparing the developmental physiology of P. canadensis from Alaska and Michigan across a range of temperatures in the laboratory and field. Higher temperatures generally resulted in more rapid larval development, but the effects varied with insect population and host. At low temperatures (12°), Alaskan larvae grew faster than Michigan larvae (fifth instars doubled their fresh mass in 5.8 vs. 9.1 d), primarily due to 40% higher consumption rates. At high temperatures (30°), Alaskan larvae grew slower, faster, or the same as Michigan larvae, depending upon host. Effects of host quality were greatest at high temperatures. Elevated respiratory expenses in Alaskan larvae (35% higher than Michigan larvae) made them especially sensitive to host quality at high temperatures. Dry matter digestibility and nitrogen use efficiency differed across hosts, but not between populations or across temperatures. Molting accounted for 35—51% of development time. Alaskan larvae completed their fifth molt faster than Michigan larvae at 12° (11.8 vs. 17.8 d), but not at 30° (3.1 vs. 2.9 d). In both populations, molt was more temperature sensitive than growth at low temperatures (Q10 of 5.65 vs. 3.04 from 12 to 18°), but less temperature sensitive at high temperatures (Q10 of 1.60 vs. 2.06 from 18 to 30°). Survival differed across temperatures, but not between populations. Under ideal basking conditions, larvae in the field were able to elevate body temperatures °10° above ambient, but such conditions were rare in Alaska and larvae were usually near ambient temperature. Alaskan larvae were no better than Michigan larvae at selecting high radiation microsites or converting solar radiation into heat. Growth rates of Alaskan larvae were the same in the field and laboratory when fed the same foliage and exposed to the same mean daily air temperature. We incorporated P. canadensis temperature responses into a life history development model, then used a 48—yr climatic record to evaluate the fitness contributions of apparent adaptations to Alaskan summers. On a good host, at Alaskan temperatures, Alaskan P. canadensis had an estimated fitness 3.0 times greater than Michigan P. canadensis. Furthermore, the Michigan population was predicted to go extinct in 31 of 48 yr at Alaskan temperatures. Changes in growth temperature responses made the greatest contribution to enhanced fitness in Alaska, followed by increased mass of neonates, enhanced molting abilities at low temperatures, and a reduced size threshold for pupation. Analysis of fitness trade—offs suggested that extreme summers have been more important than average summers in shaping adaptive responses. Regional adaptation to climate allows P. canadensis to maintain a broader geographic distribution than would otherwise be possible, but northern distribution limits are probably still constrained by summer temperatures.

Local Adaptation to Regional Climates in Papilio Canadensis (Lepidoptera: Papilionidae)

Subspecies of the eastern tiger swallowtail butterfly exhibit striking differ- ences in their ability to use quaking aspen (Populus tremuloides) and other members of the Salicaceae as larval host plants. Papilio glaucus canadensis survives and grows well on aspen, whereas Papilio glaucus glaucus does not. In earlier studies we isolated a crude fraction of aspen compounds that exhibited activity against P. g. glaucus and identified the components as a suite of four phenolic glycosides (salicin, salicortin, tremuloidin, and tremulacin). This study was designed to identify the specific phenolic glycosides, or inter- actions among glycosides, responsible for the differential abilities of Papilio subspecies to utilize quaking aspen. We bioassayed the glycosides individually and in combination against both Papilio subspecies, using neonate survival trials and fourth-instar feeding trials. None of the compounds or combinations of compounds negatively affected the survival, growth, consumption rates, or digestibility/conversion efficiencies of P. g. canadensis, or 72-h survival rates of P. g. glaucus. Salicortin and tremulacin significantly increased fourth- instar duration and decreased growth rates for P. g. glaucus, primarily by reducing con- sumption rates. Salicin and tremuloidin showed no negative effects. Combinations of gly- cosides containing salicortin and tremulacin decreased larval survival and dramatically lowered growth rates by decreasing both consumption rates and food conversion efficiencies. Observations of treated larvae indicated that these glycosides may have caused gut lesions. The active component of salicortin and tremulacin is a cyclohexenone saligenin ester, and its activity is synergized in tremulacin by the presence of a benzoyl ester on the same molecule. We propose that differences in the susceptibilities of P. g. canadensis and P. g. glaucus to the active phenolic glycosides are due to differences in activity of their carbox- ylesterase detoxication systems.

Chemical ecology of the tiger swallowtail: mediation of host use by phenolic glycosides'

Seasonal patterns in the phytochemistry of three Populus species

Hybrid speciation, or the formation of a daughter species due to interbreeding between two parental species, is a potentially important means of diversification, because it generates new forms from existing variation. However, factors responsible for the origin and maintenance of hybrid species are largely unknown. Here we show that the North American butterfly Papilio appalachiensis is a hybrid species, with genomic admixture from Papilio glaucus and Papilio canadensis. Papilio appalachiensis has a mosaic phenotype, which is hypothesized to be the result of combining sex-linked traits from P. glaucus and P. canadensis. We show that P. appalachiensis' Z-linked genes associated with a cooler thermal habitat were inherited from P. canadensis, whereas its W-linked mimicry and mitochondrial DNA were inherited from P. glaucus. Furthermore, genome-wide AFLP markers showed nearly equal contributions from each parental species in the origin of P. appalachiensis, indicating that it formed from a burst of hybridization between the parental species, with little subsequent backcrossing. However, analyses of genetic differentiation, clustering, and polymorphism based on molecular data also showed that P. appalachiensis is genetically distinct from both parental species. Population genetic simulations revealed P. appalachiensis to be much younger than the parental species, with unidirectional gene flow from P. glaucus and P. canadensis into P. appalachiensis. Finally, phylogenetic analyses, combined with ancestral state reconstruction, showed that the two traits that define P. appalachiensis' mosaic phenotype, obligatory pupal diapause and mimicry, evolved uniquely in P. canadensis and P. glaucus, respectively, and were then recombined through hybridization to form P. appalachiensis. These results suggest that natural selection and sex-linked traits may have played an important role in the origin and maintenance of P. appalachiensis as a hybrid species. In particular, ecological barriers associated with a steep thermal cline appear to maintain the distinct, mosaic genome of P. appalachiensis despite contact and occasional hybridization with both parental species.

/pdf/sex-chromosome-mosaicism-and-hybrid-speciation-among-tiger-4ckbynnc75.pdf

J. Mark Scriber

Papers

Growth of Herbivorous Caterpillars in Relation to Feeding Specialization and to the Growth Form of Their Food Plants

Local Adaptation to Regional Climates in Papilio Canadensis (Lepidoptera: Papilionidae)

Chemical ecology of the tiger swallowtail: mediation of host use by phenolic glycosides'

Seasonal patterns in the phytochemistry of three Populus species

Sex chromosome mosaicism and hybrid speciation among tiger swallowtail butterflies.