Genetic signature of Last Glacial Maximum regional refugia in a circum-Antarctic sea spider

first_imgThe evolutionary history of Antarctic organisms is becoming increasingly important to understand and manage population trajectories under rapid environmental change. The Antarctic sea spider Nymphon australe, with an apparently large population size compared with other sea spider species, is an ideal target to look for molecular signatures of past climatic events. We analysed mitochondrial DNA of specimens collected from the Antarctic continent and two Antarctic islands (AI) to infer past population processes and understand current genetic structure. Demographic history analyses suggest populations survived in refugia during the Last Glacial Maximum. The high genetic diversity found in the Antarctic Peninsula and East Antarctic (EA) seems related to multiple demographic contraction–expansion events associated with deep-sea refugia, while the low genetic diversity in the Weddell Sea points to a more recent expansion from a shelf refugium. We suggest the genetic structure of N. australe from AI reflects recent colonization from the continent. At a local level, EA populations reveal generally low genetic differentiation, geographically and bathymetrically, suggesting limited restrictions to dispersal. Results highlight regional differences in demographic histories and how these relate to the variation in intensity of glaciation–deglaciation events around Antarctica, critical for the study of local evolutionary processes. These are valuable data for understanding the remarkable success of Antarctic pycnogonids, and how environmental changes have shaped the evolution and diversification of Southern Ocean benthic biodiversity.last_img read more

Tifton Ag Ed

first_imgThe newest addition to the University of Georgia Tifton Campus faculty has a hefty goal: train the best agriculture teachers in the nation and produce enough graduates to fill all of the open agricultural education teaching positions in Georgia.Amber Rice, who joined UGA prior to the beginning of fall semester, specializes in agricultural education and has a 75 percent teaching appointment. Agricultural education is the campus’ most popular major, with 26 students enrolled in the major this fall.“We were delighted to welcome Amber Rice to the UGA Tifton Campus. She leads the agriculture teacher preparation major at UGA Tifton, offering cutting-edge courses and experiences for emerging teachers,” said Kay Kelsey, head of the UGA College of Agricultural and Environmental Sciences’ Department of Agricultural Leadership, Education and Communication. “Dr. Rice specializes in pedagogical content knowledge, or researching the ability of teachers to transmit knowledge to learners.”Rice is participating in research to make sure future agriculture teachers graduate with top-notch training. Pedagogical training involves researching ways to teach a particular subject to a specific audience. In Rice’s case, she is searching for ways to teach agricultural knowledge more effectively.“How can we better prepare our student teachers to teach content in the best ways. What are the best ways to teach plant science so that students are really grasping that material?” Rice said. These are just some of the questions she hopes to answer with her research, which is mostly qualitative through student and teacher interviews.Working in an agricultural community like Tifton and becoming a member of the college faculty was an opportunity Rice could not pass up. She cherishes the one-on-one training she’s able to provide students on a small campus like UGA Tifton.“I really enjoy working with students. I like the small atmosphere of the Tifton Campus with the resources and perks of being at a land-grant university like UGA,” Rice said. “Especially with these students, probably 95 percent of them are going to be agriculture teachers. Everybody has their own strengths and things they want to work on. Having that personal relationship and being able to work with each individual student, I feel like it’s going to make them better teachers in the classroom.” The number of agriculture teachers and programs is growing rapidly in Georgia. Kelsey said there are more than 38,000 National FFA Organization members, up from 35,000 two years ago. Agriculture teachers typically serve as advisors for these students.But, the number of UGA students interested in becoming teachers is decreasing. There were more than 50 agriculture teacher openings in Georgia last year, but only 25 new UGA agricultural education graduates were available to fill them. “The rest came from other states, other disciplines (science teachers) and industry (people) who were not traditionally certified,” said Kelsey.Rice says the shortage of qualified agriculture teachers is a problem across the nation.“We’re just not producing enough to fill all the positions,” she said. “Last year, 100 percent of our agriculture teachers found jobs. The industry wants them. They want our Tifton graduates. There are jobs for them in Georgia.”To learn more about the agricultural education program on the UGA Tifton Campus or to contact Rice, call (229) 386-3528. Information about the academic program at UGA Tifton can also be accessed at read more