Pollution drives extinction by speciation reversal in replicate adaptive radiations
Friday 3 June 2011
Preserving biodiversity is one of society’s greatest challenges. The diversity of species is being rapidly lost through two different but potentially interacting mechanisms: negative population growth and loss of distinctiveness through introgressive hybridization. Here we analyzed historical and contemporary phenotypic and genetic data on species diversity in replicate adaptive radiations of whitefish from 17 large European lakes. We provide evidence that anthropogenic eutrophication, through shrinking reproductive niche space and relaxing divergent selection, has driven parallel extinction of endemic species through the reversal of ecological speciation. The magnitude of organic pollution explains a large fraction of species loss and the degree of genetic distinctiveness among remaining species. We suggest that rapid diversity loss through speciation reversal is more widespread than currently appreciated. Such extinctions can only be prevented if conservation efforts, along with protecting existing species, identify and protect the ecological and evolutionary processes that generate species.
Speaker: Dr. David Bittner
Location: CUNNINGHAM BUILDING – 146
Time: 2:30 pm
Pricing: Free, all are welcome.
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The North Pacific – An Ocean in Transition
Tuesday 7 June 2011
In his lecture, Dr. Denman will show how dynamic and interconnected the weather, the climate and our oceans are. Emphasizing the North Pacific, he will show how the climate and our oceans are changing in response to human activities, and present projections on how these changes will continue over the 21st century. In particular, he will present observations of near surface warming and increasing stratification, decreasing subsurface oxygen concentrations, and increasing carbon dioxide and the resulting acidification of the North Pacific Ocean, especially the coastal ocean along the North American shoreline. Finally, he will describe and illustrate how these changes will affect ocean planktonic ecosystems, and how these ecosystems might respond and adapt to their changing environment.
Speaker: Dr. Ken Denman, Chief Scientist Venus Network, University of Victoria and Environment Canada
Location: Victoria Conference Centre, 720 Douglas St. – Main Lecture Theatre
Time: 7:30 pm
Pricing: Free, all are welcome.
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Exploring ocean frontiers – we have more to learn
Thursday 9 June 2011
The human species is limited by terrestrial adaptations and dependence on a few senses to understand our interactions with the environment. Penetration of the oceans by humans is difficult. Lack of visual connectivity beneath the sea surface usually means “out of sight, out of mind.” Together, we will explore some of the deep places in our ocean to reveal some unknown wonders. Imagery from expeditions to hot vents, subsea volcanoes, and deep into Canadian oceans illustrates the beauty and the extraordinary dynamics of ecosystems that we never see. Canada is a leader in development of subsea technologies that allow us to undertake such exploration: submersible, remotely operated vehicles and subsea observatories are world leading. We will also look to the role of new young scientists in dealing with the growing threats to the ocean. Communication and education is possibly the best approach to ensuring better stewardship of the oceans.
Speaker: Dr. Verena Tunnicliffe, Canada Research Chair in Deep Ocean Research, Univeristy of Victoria
Location: Victoria Conference Centre, 720 Douglas St. – Main Lecture Theatre
Time: 7:30 pm
Pricing: Free, all are welcome.
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