Interspecific hybridization explains rapid gorget colour divergence in Heliodoxa hummingbirds (Aves: Trochilidae)

Hybridization is a known source of morphological, functional and communicative signal novelty in many organisms. Although diverse mechanisms of established novel ornamentation have been identified in natural populations, we lack an understanding of hybridization effects across levels of biological scales and upon phylogenies. Hummingbirds display diverse structural colours resulting from coherent light scattering by feather nanostructures. Given the complex relationship between feather nanostructures and the colours they produce, intermediate coloration does not necessarily imply intermediate nanostructures. Here, we characterize nanostructural, ecological and genetic inputs in a distinctive Heliodoxa hummingbird from the foothills of eastern Peru. Genetically, this individual is closely allied with Heliodoxa branickii and Heliodoxa gularis, but it is not identical to either when nuclear data are assessed. Elevated interspecific heterozygosity further suggests it is a hybrid backcross to H. branickii. Electron microscopy and spectrophotometry of this unique individual reveal key nanostructural differences underlying its distinct gorget colour, confirmed by optical modelling. Phylogenetic comparative analysis suggests that the observed gorget coloration divergence from both parentals to this individual would take 6.6–10 My to evolve at the current rate within a single hummingbird lineage. These results emphasize the mosaic nature of hybridization and suggest that hybridization may contribute to the structural colour diversity found across hummingbirds

Medicinal Plants of the Peruvian Amazon: Bioactive Phytochemicals, Mechanisms of Action, and Biosynthetic Pathways

The objective of this book chapter is to provide consolidated and updated scientific information about the medicinal plants of the Peruvian Amazon, which has a great richness of plants; many of these are used in folkloric medicine to treat several diseases. Recently, investigations have reported that these medicinal plants possess bioactive phytochemicals against several diseases such as diabetes, cancer, inflammation, infectious diseases, and several other health problems, thus corroborating some ethnopharmacological reports. The mechanism of action for selected bioactive phytochemicals was demonstrated at the molecular level as well as the metabolic pathways involved in their biosynthesis were described. Due to the large gap in scientific information revealed in this review, we formulated a series of strategies to close these scientific knowledge gaps and achieve a sustainable exploitation of medicinal plants in the Peruvian Amazon

Maternal Effects on Brood Reduction in Common Grackles

127 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2009.The main goal of my dissertation research was to investigate how maternal effects influence offspring productivity in common grackles ( Quiscalus quiscula). Maternal effects are largely considered adaptive, but my research provides little supporting evidence because few of the maternal effects I assessed were relevant. In general, asynchronous hatching had by far the largest effect on offspring performance even when additional maternal effects were present. However, I found that egg size can have positive effects on nestling growth and survival especially early in the nesting period, but those effects are largely overwhelmed by asynchronous hatching. Adaptive evidence is lacking in the two other maternal effects---sex and yolk hormones---in which I focused. I found that brothers and sisters are equally susceptible to starvation even when environmental conditions are extremely poor. This suggests that mothers cannot increase the number of fledglings they produce by preferentially allocating sex. I did not find the predicted patterns of yolk testosterone and estradiol relative to clutch size and laying order that would suggest yolk hormones act as a compensatory mechanism to offset the deleterious effects of asynchronous hatching. Finally, I found a disconnect between the maternal effects that were beneficial to mothers versus their offspring. Within nests offspring that hatched earlier than their siblings were heavier and more likely to fledge, whereas among nests mothers that initiated their clutches early in the breeding season fledged more young than females breeding later in the population. Thus, the one maternal effect that repeatedly had the largest impact on offspring performance had absolutely no effect on the productivity of mothers in the short term. There are two ways to interpret this result. First, asynchronous hatching may be a nonadaptive hormonal constraint that for some reason varies extensively among females. Second, asynchronous hatching may enable mothers to increase their productivity in the long term by adjusting brood size to food availability in the short term. Consequently, future research regarding the adaptive allocation of maternal effects in common grackles should focus on identifying the strategies of mothers in the short term that may increase their fitness in the long term.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD