title: Historical biogeography of the Gondwanan freshwater genus Boeckella (Crustacea): Timing and modes of speciation in the Southern Hemisphere

authors: Maturana, Claudia S.

subjects: Science & Technology

abstract: Aim
We investigated evolutionary relationships and biogeographical patterns within the genus Boeckella to evaluate (1) whether its current widespread distribution in the Southern Hemisphere is due to recent long-distance dispersal or long-term diversification; and (2) the age and origin of sub-Antarctic and Antarctic Boeckella species, with particular focus on the most widely distributed species: Boeckella poppei.

Location
South America, sub-Antarctic islands, maritime Antarctica, continental Antarctica and Australasia.

Methods
To reconstruct phylogenetic patterns of Boeckella, we used molecular sequence data collected from 12 regions and applied Bayesian and Maximum Likelihood analyses using multiple loci. We also estimated divergence times and reconstructed ancestral ranges using two different models of species evolution.

Results
Phylogenetic analyses and divergence time estimates suggested that Boeckella originated on the Gondwanan supercontinent and initially split into two main clades during the late Cretaceous (ca. 80 Ma). The first clade diversified in Australasia, and the second clade is currently distributed in South America, various sub-Antarctic islands and Antarctica. Dispersal from South America to the Kerguelen and Crozet archipelagos occurred during the Eocene/Oligocene (B. vallentini) and in the late Pliocene (B. brevicaudata), while South Georgia and the maritime Antarctic were likely colonized during the late Pleistocene (B. poppei).

Main conclusions
Boeckella has a Gondwanan origin, with further diversifications after the physical separation of the continental landmasses. Extant populations of Boeckella from the Scotia Arc islands and Antarctic Peninsula originated from South America during the Pleistocene, suggesting that original Antarctic Gondwanan lineages did not survive repeated glacial cycles during the Quaternary ice ages. A continuous decline in the species accumulation rate is apparent within the genus as the early Eocene, suggesting that Boeckella diversification may have decreased due to progressive cooling throughout the Cenozoic era.

text: Historical biogeography of the Gondwanan freshwater genus Boeckella (Crustacea): Timing and modes of speciation in the Southern Hemisphere Aim
We investigated evolutionary relationships and biogeographical patterns within the genus Boeckella to evaluate (1) whether its current widespread distribution in the Southern Hemisphere is due to recent long-distance dispersal or long-term diversification; and (2) the age and origin of sub-Antarctic and Antarctic Boeckella species, with particular focus on the most widely distributed species: Boeckella poppei.

Location
South America, sub-Antarctic islands, maritime Antarctica, continental Antarctica and Australasia.

Methods
To reconstruct phylogenetic patterns of Boeckella, we used molecular sequence data collected from 12 regions and applied Bayesian and Maximum Likelihood analyses using multiple loci. We also estimated divergence times and reconstructed ancestral ranges using two different models of species evolution.

Results
Phylogenetic analyses and divergence time estimates suggested that Boeckella originated on the Gondwanan supercontinent and initially split into two main clades during the late Cretaceous (ca. 80 Ma). The first clade diversified in Australasia, and the second clade is currently distributed in South America, various sub-Antarctic islands and Antarctica. Dispersal from South America to the Kerguelen and Crozet archipelagos occurred during the Eocene/Oligocene (B. vallentini) and in the late Pliocene (B. brevicaudata), while South Georgia and the maritime Antarctic were likely colonized during the late Pleistocene (B. poppei).

Main conclusions
Boeckella has a Gondwanan origin, with further diversifications after the physical separation of the continental landmasses. Extant populations of Boeckella from the Scotia Arc islands and Antarctic Peninsula originated from South America during the Pleistocene, suggesting that original Antarctic Gondwanan lineages did not survive repeated glacial cycles during the Quaternary ice ages. A continuous decline in the species accumulation rate is apparent within the genus as the early Eocene, suggesting that Boeckella diversification may have decreased due to progressive cooling throughout the Cenozoic era.

year: 2021-09-14

title: Conclusion

authors: Williams, P. John

subjects: education

abstract: As the preceding papers have illustrated, there are two innovations within project e-scape. The first concerns the development of an e-portfolio system that enables learners to capture evidence of their activity (using hand-held devices in the workshop/studio/science lab/playing field) and to lodge it in a web-space where their portfolio emerges dynamically, in real-time. Teachers and examination bodies can interact with this system to a greater or lesser extent according to the circumstances. If the activity is part of a formal examination, then the Awarding Body can specify the task and the activity framework (all of which can be downloaded by the school) and teachers in many schools can then run the same activity in a standard way. If the activity is a normal piece of curriculum, then teachers can design activities for individuals or groups of learners and either run them with the learners, or enable the learners themselves to work through the activity autonomously. In any event, the outcome of all this is a web-portfolio.
The second innovation concerns the assessment of these portfolios. Using comparative judgement and the pairs engine, groups of teachers and/or examiners can collaborate in the assessment of groups of portfolios. This might be for an Awarding Body, with the results counting towards an official award, or it might be within a school, where collaborating teachers use the data for their own purposes. These two innovations were launched in 2009 with the final report of phase 3 of the e-scape project. The purpose of this concluding piece is to reflect on what has happened since then; on the extent to which these innovations have been adopted in various parts of the world and the issues that this adoption is raising. Sometimes the adoption has been of only one of the innovations (either the portfolio-building or the comparative judgement), and sometimes it has been both.

text: Conclusion As the preceding papers have illustrated, there are two innovations within project e-scape. The first concerns the development of an e-portfolio system that enables learners to capture evidence of their activity (using hand-held devices in the workshop/studio/science lab/playing field) and to lodge it in a web-space where their portfolio emerges dynamically, in real-time. Teachers and examination bodies can interact with this system to a greater or lesser extent according to the circumstances. If the activity is part of a formal examination, then the Awarding Body can specify the task and the activity framework (all of which can be downloaded by the school) and teachers in many schools can then run the same activity in a standard way. If the activity is a normal piece of curriculum, then teachers can design activities for individuals or groups of learners and either run them with the learners, or enable the learners themselves to work through the activity autonomously. In any event, the outcome of all this is a web-portfolio.
The second innovation concerns the assessment of these portfolios. Using comparative judgement and the pairs engine, groups of teachers and/or examiners can collaborate in the assessment of groups of portfolios. This might be for an Awarding Body, with the results counting towards an official award, or it might be within a school, where collaborating teachers use the data for their own purposes. These two innovations were launched in 2009 with the final report of phase 3 of the e-scape project. The purpose of this concluding piece is to reflect on what has happened since then; on the extent to which these innovations have been adopted in various parts of the world and the issues that this adoption is raising. Sometimes the adoption has been of only one of the innovations (either the portfolio-building or the comparative judgement), and sometimes it has been both.

year: 2011

title: Imagining our own approaches

authors: Smith, Linda Tuhiwai

abstract: I spent some formative years of my life either in the back of museums or their basements helping my father, a scholar of Māori Studies, and keeping myself out of trouble. In the late 1960s I had one small job in the library basement of the Peabody Museum in Salem, Massachusetts, typing new labels for the captains’ log books of ships that were sailing during the American Revolution. I read most of those journals that consisted of pages and pages of wind directions with the rare glimpse of an encounter with another ship or a list of supplies. Why were we there in Salem when we came from Aotearoa, New Zealand? We were there because Salem was the home base for ships that sailed into the Pacific and returned home with collections of materials from the various Pacific Islands countries they visited. My father was studying elaborately carved items from the Marquesa Islands that looked very much like Māori designs.

text: Imagining our own approaches I spent some formative years of my life either in the back of museums or their basements helping my father, a scholar of Māori Studies, and keeping myself out of trouble. In the late 1960s I had one small job in the library basement of the Peabody Museum in Salem, Massachusetts, typing new labels for the captains’ log books of ships that were sailing during the American Revolution. I read most of those journals that consisted of pages and pages of wind directions with the rare glimpse of an encounter with another ship or a list of supplies. Why were we there in Salem when we came from Aotearoa, New Zealand? We were there because Salem was the home base for ships that sailed into the Pacific and returned home with collections of materials from the various Pacific Islands countries they visited. My father was studying elaborately carved items from the Marquesa Islands that looked very much like Māori designs.

year: 2015