LEARNING The objectives of BIOS 781 are to present: OBJECTIVES: 1. basic population and quantitative genetic principles, including classical genetics, chromosomal theory of inheritance, and meiotic recombination 2. an exposure to QTL mapping methods of complex quantitative traits and linkage methods to detect co-segregation with disease 3. methods for assessing marker-disease linkage disequilibrium, including case-control approaches 4. methods for genome-wide association and stratification control.

Genetic Data Analysis

Ecosystem services are the benefits obtained from the environment that increase human well-being. Economic valuation is conducted by measuring the human welfare gains or losses that result from changes in the provision of ecosystem services. Bats have long been postulated to play important roles in arthropod suppression, seed dispersal, and pollination; however, only recently have these ecosystem services begun to be thoroughly evaluated. Here, we review the available literature on the ecological and economic impact of ecosystem services provided by bats. We describe dietary preferences, foraging behaviors, adaptations, and phylogenetic histories of insectivorous, frugivorous, and nectarivorous bats worldwide in the context of their respective ecosystem services. For each trophic ensemble, we discuss the consequences of these ecological interactions on both natural and agricultural systems. Throughout this review, we highlight the research needed to fully determine the ecosystem services in question. Finally, we provide a comprehensive overview of economic valuation of ecosystem services. Unfortunately, few studies estimating the economic value of ecosystem services provided by bats have been conducted to date; however, we outline a framework that could be used in future studies to more fully address this question. Consumptive goods provided by bats, such as food and guano, are often exchanged in markets where the market price indicates an economic value. Nonmarket valuation methods can be used to estimate the economic value of nonconsumptive services, including inputs to agricultural production and recreational activities. Information on the ecological and economic value of ecosystem services provided by bats can be used to inform decisions regarding where and when to protect or restore bat populations and associated habitats, as well as to improve public perception of bats.

/pdf/ecosystem-services-provided-by-bats-2clwslocl0.pdf

Ecosystem services provided by bats

Ecosystem services are natural processes that benefit humans. Birds contribute the four types of services recognized by the UN Millennium Ecosystem Assessment-provisioning, regulating, cultural, and supporting services. In this review, we concentrate primarily on supporting services, and to a lesser extent, provisioning and regulating services. As members of ecosystems, birds play many roles, including as predators, pollinators, scavengers, seed dispersers, seed predators, and ecosystem engineers. These ecosystem services fall into two subcategories: those that arise via behavior (like consumption of agricultural pests) and those that arise via bird products (like nests and guano). Characteristics of most birds make them quite special from the perspective of ecosystem services. Because most birds fly, they can respond to irruptive or pulsed resources in ways generally not possible for other vertebrates. Migratory species link ecosystem processes and fluxes that are separated by great distances and times. Although the economic value to humans contributed by most, if not all, of the supporting services has yet to be quantified, we believe they are important to humans. Our goals for this review are 1) to lay the groundwork on these services to facilitate future efforts to estimate their economic value, 2) to highlight gaps in our knowledge, and 3) to point to future directions for additional research.

Ecosystem Services Provided by Birds

The Agave (Agavaceae) are keystone species of semiarid to arid regions where the geographic center of origin is Mexico but whose populations spread from the southwestern U.S. through Central America, the Caribbean, and into northern South America. Our analyses indicate that Agave is a young genus, between 7.8 and 10.1 million years old, and yet it harbors the most species of any genera in the family. Of the eight genera in the family, Agave is paraphyletic with respect to three of them, and these four genera are often grouped into a genus termed Agave sensu lato, which harbors 208 of the 293 recognized species in the Agavaceae. In this article, we examine the phylogenetic limits of Agave sensu lato and present analyses elucidating the origin and rate of speciation in the group. These analyses lead to some new insights into the phylogenetic limits of Agave, indicate an estimated age of the family between 20 and 26 million years and an age of the Agave sensu lato of ≤10 million years. Furthermore, we estimate a high mean per-lineage rate of diversification for the genus and find that rates of speciation were significantly elevated between 8 and 6 million years ago and then again between 3 and 2.5 million years ago. We discuss the potential for both monocarpy and the evolution of a generalist pollination system, largely dependent on nectarivorous bat species, as possible driving factors in the radiation of the group.

https://www.pnas.org/content/pnas/103/24/9124.full.pdf

Timing and rate of speciation in Agave (Agavaceae)

Wind-turbine operations are associated with bat mortality worldwide; minimizing these fatalities is critically important to both bat conservation and public acceptance of wind-energy development. We tested the effectiveness of raising wind-turbine cut-in speed – defined as the lowest wind speed at which turbines generate power to the utility system, thereby reducing turbine operation during periods of low wind speeds – to decrease bat mortality at the Casselman Wind Project in Somerset County, Pennsylvania, over a 2-year period. Observed bat mortality at fully operational turbines was, on average, 5.4 and 3.6 times greater than mortality associated with curtailed (ie non-operating) turbines in 2008 and 2009, respectively. Relatively small changes to wind-turbine operation resulted in nightly reductions in bat mortality, ranging from 44% to 93%, with marginal annual power loss (≤ 1% of total annual output). Our findings suggest that increasing turbine cut-in speeds at wind facilities in areas of conservati...

Altering turbine speed reduces bat mortality at wind-energy facilities

Floral characteristics such as morphology and flower color have been interpreted as adaptive traits that evolved through selective pressures generated by pollinators. Differences among populations in the expression of floral characters could result from natural selection for their adaptive value to local conditions. We describe the patterns of variation of flower morphology, color, and fecundity of Agave lechuguilla in 11 populations along a latitudinal gradient encompassing the whole range of the species in the Chihuahuan desert. We found a latitudinal pattern in flower shape and color. Flowers tended to be shorter, more open, and colorful toward the northern part of the gradient. We also recorded flower visitation, discriminating between pollinators and floral robbers. The main pollinators seems to be nocturnal hawk moths (Hyles lineata) and diurnal large bees (Bombus pennsylvanicus and Xylocopa californica). In all populations large bees were the most abundant potential pollinators. However, the abundance of the potential pollinators varied along the gradient. We observed no bat visits along the gradient. The number of visits by all potential pollinators decreased significantly with latitude as did fruit set.

Geographic patterns in the reproductive ecology of Agave lechuguilla (Agavaceae) in the Chihuahuan desert. I. Floral characteristics, visitors, and fecundity.

Agavaceae are an American family that comprises nine genera and ca. 300 species distributed in arid and semiarid environments, mainly in Mexico. The family is very successful and displays a wide array of ecological, reproductive, and morphological adaptations. Many of its members play important roles as keystone species, because they produce abundant resources during the reproductive season. In this paper we analyze the current knowledge about the pollination ecology of the different genera in the family and the role that pollination systems have played in the ecological and phylogenetic success of the group. After providing an overview of each of the genera in the family, we discuss in detail aspects of the reproductive ecology of species in the genus Agave s.l., which is composed of ca. 208 species and includes subgenera of Agave (Agave and Littaea), Manfreda, Polianthes, and Prochnyanthes. Finally, we describe the results of analyses to test the hypothesis that there has been an adaptive radiation in the genus Agave. Using chloroplast and nuclear DNA sequences we estimate the age of the Agavaceae family and the genus Agave to be 12-26 millions of years ago (MYA) and 10 MYA, respectively, and show that mean rates of diversification were higher in the genus Agave than the genus Yucca. The values we report for rates of diversification in Agave s.l. are high when compared to other radiations in plants and animals. We suggest that the desertification of North America, which started ca. 15 MYA was critical in the radiation of agaves and that the generalist pollination system of Agave has been more successful in generating new species than the extreme specialization of Yucca.

/pdf/pollination-biology-and-adaptive-radiation-of-agavaceae-with-4vdjhgncdw.pdf

Pollination Biology and Adaptive Radiation of Agavaceae, with Special Emphasis on the Genus Agave

The Agavaceae family comprises eight genera with contrasting reproductive biologies, given that they can be iteroparous (if they can reproduce several times), or semelparous ( if each individual produces an inflorescence and then dies); they also display a wide variety of  floral morphologies and of pollinators (from bees to bats, including hummingbirds and moths). Here we review their reproductive biology and attempt a synthesis of their population genetics and evolution. In order to do these analyses, we reconstructed their phylogeny using ITS l and ITS 2 data, and calibrated a molecular clock. We use Hasta for comparisons, although we review some genera that have been considered related to the family. To close the paper, we discuss the evolutionary patterns in the family, mapping the different characters in the phylogeny.

/pdf/evolucion-de-la-familia-agavaceae-filogenia-biologia-57xzxvvkrh.pdf

Evolución de la familia Agavaceae: filogenia, biología reproductiva y genética de poblaciones

Plants with natural variation in their floral traits and reproductive ecology are ideal subjects for analyzing the effects of natural selection and other evolutionary forces on genetic structure of natural populations. Agave lechuguilla shows latitudinal changes in floral morphology, color, and nectar production along its distribution through north-central Mexico. Both the type and abundance of its pollinators also change with latitude. Using starch electrophoresis, we examined the levels and patterns of variation of 13 polymorphic allozyme loci in 11 populations of A. lechuguilla. The overall level of genetic variability was high ( He 5 0.394), but the levels of genetic variation had no geographic pattern. However, the southern populations exhibited an excess of heterozygotes in relation to expectations for Hardy-Weinberg equilibrium, whereas the northern populations had an excess of homozygotes. Total differentiation among populations was low ( u5 0.083), although gene flow estimates ( Nm) varied among groups of populations: southern populations had the lowest levels of genetic differentiation, suggesting high levels of gene flow; northern populations had greater levels of genetic differentiation ( u5 0.115), suggesting low gene flow among them. The patterns and inferences of the genetic structure of the population at the molecular level is consistent with variation in floral traits and pollinator visitation rates across the range of the species.

https://bsapubs.onlinelibrary.wiley.com/doi/pdf/10.3732/ajb.90.5.700

Geographic patterns in the reproductive ecology of Agave lechuguilla (Agavaceae) in the Chihuahuan desert. II. Genetic variation, differentiation, and inbreeding estimates.

Background: Reproductive traits are features of a species’ biology that may determine its rarity, as they affect its genetic diversity and structure, as well as its population dynamics. Study species : The rare and threatened species Furcraea parmentieri , whose distribution is limited to the Trans-Mexican volcanic belt.  Questions: How is the reproductive phenology of F. parmentieri ? Does flower morphology vary between individuals? Does it produce nectar? Which animals visit its flowers? Is it self-compatible? Do the seeds originated via different pollination treatments show differences in their germinability? Study sites and dates: We studied the F. parmentieri from 2007 to 2008, at El Xitle volcano (altitude: 2800 – 3100 m; pine-oak forest), in the south of Mexico City. Methods: Reproductive phenology was recorded through fortnightly visits to the study site. Flowers were collected, flower visitors were recorded and nectar production was measured. An experiment was done which included four treatments: autonomous pollination, geitonogamy, cross pollination, and a control. We measured seed set, fruit set and seed germination in each treatment. Results: Inflorescences started in January and flowering finished in May. Fruit maturation took from May to November. Nectar production was negligible. Flowers were visited by hawkmoths and hummingbirds. Fruit set was very low (ca. 5 %) and we observed self-incompatibility.  Conclusions: Fucraeae parmentieri  presents a low fruit set due to pollinator limitation. However the population seems to be thriving. The main threat faced by this species is the high land-use change rate along its distribution range, as well as climate change.

/pdf/reproductive-biology-of-the-threatened-species-furcraea-5qon1hjkx2.pdf

Arturo Silva-Montellano

Papers

Geographic patterns in the reproductive ecology of Agave lechuguilla (Agavaceae) in the Chihuahuan desert. I. Floral characteristics, visitors, and fecundity.

Pollination Biology and Adaptive Radiation of Agavaceae, with Special Emphasis on the Genus Agave

Evolución de la familia Agavaceae: filogenia, biología reproductiva y genética de poblaciones

Geographic patterns in the reproductive ecology of Agave lechuguilla (Agavaceae) in the Chihuahuan desert. II. Genetic variation, differentiation, and inbreeding estimates.

Reproductive biology of the threatened species Furcraea parmentieri (Aspargaceae)