Lineages undergoing rapid radiations provide exceptional opportunities for studying speciation and adaptation, but also represent a challenge for molecular systematics because retention of ancestral polymorphisms and the occurrence of hybridization can obscure relationships among lineages. Dolphins in the subfamily Delphininae are one such case. Non-monophyly, rapid speciation events, and discordance between morphological and molecular characters have made the inference of phylogenetic relationships within this subfamily very difficult. Here we approach this problem by applying multiple methods intended to estimate species trees using a multi-gene dataset for the Delphininae (Sousa, Sotalia, Stenella, Tursiops, Delphinus and Lagenodelphis). Incongruent gene trees obtained indicate that incomplete lineage sorting and possibly hybridization are confounding the inference of species history in this group. Nonetheless, using coalescent-based methods, we have been able to extract an underlying species-tree signal from divergent histories of independent genes. This is the first time a molecular study provides support for such relationships. This study further illustrates how methods of species-tree inference can be very sensitive both to the characteristics of the dataset and the evolutionary processes affecting the evolution of the group under study.
Green Mountain Power: Residential batteries saved customers $500,000 during heat wave FacebookTwitterLinkedInEmailPrint分享WCAX:While other power companies were telling customers to reduce how much energy they used during the recent heat wave, Green Mountain Power was focused on a different tactic.For years, GMP has worked on creating a system of stored energy to rely on during peak energy days, and GMP Vice President Josh Castonguay says it worked like planned. Castonguay says to save money in Vermont, power was pulled from 500 Tesla Powerwalls, as well as energy storage facilities in Rutland and Panton.Think of it like a game. GMP waits until the moment of peak usage and then sends out all their stored energy to the grid. That reduces the need for dirty and expensive backup generators to be brought online.Castonguay says the battery strategy paid off. “All three of those combined, during that peak hour that’s happened this summer, are the equivalent of that, basically worth up to half a million dollars for customers and it’s about the equivalent of taking 5,000 homes off the grid during that one hour of the peak,” he said.“When New England hits that peak, every state has to share in the cost of the bulk system. So everything, each state, each utility, can do to lower the peak during that time is what saves that money,” said Castonguay.So far, 500 Tesla Powerwalls are installed around Vermont with 1,500 more expected to go out. Castonguay says they’ll be ready if another big peak pops up this summer. “We’re installing more Powerwalls every day, so we’ll have more to use if something else comes up this summer,” he said.More: GMP credits big batteries for saving money during heat wave