Bats Pollinating – Photos – Plant World News

A common theme in angiosperm diversification involves repeated evolution of suites of traits, termed pollination syndromes, that adapt a flower to a certain type of pollinator. But why specialize to a given pollinator, when generalizing ought to allow many more opportunities for successful pollination per unit time? Work with the genus Burmeistera (Campanulaceae) showed that most species are specialized to either bats or hummingbirds (Muchhala 2006a), and experiments demonstrated that an adaptive tradeoff in floral form (wide flowers fit bat heads better while narrow flowers fit hummingbird bills better) is strong enough that generalist flowers are suboptimal (Muchhala 2007). We are continuing to explore the traits that adapt flowers to bat pollination, such as increased pollen production (e.g. Muchhala et al. 2010), and olfactory, visual, and echo-reflectance cues.	Burmeistera borjensis flower with Anoura geoffroyi (A) and B. rubrosepala with Adelomyia melanogenys (B)
Anoura fistulata drinking honey-water from a glass tube (top) and pollinating Centropogon nigricans (bottom) Be sure that the website demands you to have generic viagra cheapest a valid prescription. The task can be harmless, but more often than not, individuals either chose to ignore it or are unable to regain their normal lovemaking capability can take the remedy to revive canada viagra cialis their relationships. This could be due to a number of reasons which can cialis professional for sale http://www.4frontimports.com/wines/ace-and-able lead to erectile dysfunction. This herbal pill is recommended for young as well as excellent results as it never disappoints any levitra viagra online pharmacy shop link of its medicinal properties.	Specialization in pollination systems (continued) The majority of flowers are pollinated by more than one species, and pollinators typically visit many species of flowers, thus pollination syndromes are examples of either one-sided evolution (plants evolving to pollinators) or, at best, diffuse coevolution. True reciprocal coevolution can only occur in highly specialized interactions. One example of this is the nectar bat Anoura fistulata (Muchhala et al. 2005), which can launch its tongue 1.5 times its body length (double that of other bats and longer than any other mammal). Unique adaptations allow it to store its tongue in its rib cage (Muchhala 2006b). Experiments suggest that this pair is involved in a coevolutionary race with the 9-cm-long flowers of Centropogon nigricans; longer tongues allow bats to reach more nectar, while longer flowers maximize pollen transfer (Muchhala & Thomson 2009). We plan to continue to study the geographic mosaic of the interaction between this bat and the flowers it pollinates throughout its range, as well as the ‘trigger’ behind the coevolutionary race – that is, why exactly do long flowers receive more pollen?
Competition for pollination A given species of plant occurs within a community of many other plants. How does an individual ensure that it will receive conspecific pollen and that its pollen reaches conspecifics? The costs of competition may include loss of pollen to foreign flowers or blockage of stigmas with foreign pollen. Bat-pollinated Burmeistera demonstrate one solution to this problem: co-occurring species have evolved different lengths of the staminal column, thus placing pollen on different regions of bat’s heads (Muchhala & Potts, 2007). This system provides a rare example of character displacement in plants. We are currently testing the hypothesis that Burmeistera also demonstrate character displacement in the floral cues (odor, echo-reflectance) used to attract bats. Local differences in cues would be expected to encourage bats to stick to a single Burmeistera species during foraging bouts, and thus would reduce interspecific pollen transfer.	Floral character displacement in pollen placement: pollen transfer experiments (top) and bat with pollen from by two different Burmeistera species (bottom)
Preliminary phylogenetic hypothesis for Burmeistera (top) and a sampling of floral diversity across the genus (bottom)	Plant speciation What evolutionary innovations allowed the remarkable and rapid radiation of flowering plants? One long-standing paradigm holds that coevolution with pollinators is the key (reviewed in Armbruster & Muchhala 2009), because speciation rates are directly amplified via pollinator-mediated reproductive isolation. Post-pollination processes have received much less attention. To begin to understand the relative importance of different isolating barriers for angiosperm speciation, they must be compared among multiple sister-species pairs of various ages; in this way we can distinguish those that directly contributed to speciation from those that only arose after speciation was complete. We are currently developing molecular phylogenies for Burmeistera and the North American genus Downingia (Campanulaceae), and will use these in combination with cross-pollination experiments to explore the importance of various pre- and post-zygotic reproductive barriers in the diversification of these clades.