Bear-Human Interactions in Kluane National Park and Reserve
Sandra MacDougall, M.E.Des., Instructor, Red Deer College
Saturday, July 26, 2008, 7:30 pm Kluane National Park VRC, Haines Junction
Sunday, July 27, 2008, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Since 1997, Sandra MacDougall has reviewed many of the reported bear-human interactions along different trails and routes in Kluane National Park and Reserve. In some cases, her work has resulted in changes in park management. Join her as she outlines some of the highlights of her analyses over the years, and explores trends in bear-human interactions in Kluane.
The Eye-in-the-Sky: Changes in Arctic Sea Ice and Climate over the Past 30 Years
Ellsworth LeDrew, Professor of Geography
Sunday, June 1, 2008, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Since 1978, a succession of satellites has been passing over the poles recording specific characteristics of the sea ice and snow cover. Using sensors that can record surface information regardless of cloud cover or existence of sunlight, we have built up an extensive picture of the dramatic change in the polar environment that we now know is linked to the human contribution to global warming. Because of the positive feedbacks between snow/ice and the atmosphere, or the ‘leverage’ effect, the impact of this warming is enhanced in the polar regions. Consequently, what happens in the far north is an early indicator, or ‘canary in the coal mine’ of what might happen to the rest of the world.
Dr. LeDrew will illustrate the dramatic decline of sea ice in the Arctic Basin through a time series of satellite images. As sea routes in the Arctic Basin and the Archipelago are opened, there will be significant implications for Canadian Sovereignty, resource exploration, and people’s way of life. How should Canada and its citizens respond?
Cape Farewell: Art, Climate Change and Youth
Martin Rose, Director of the British Council in Canada
Sunday, May 25, 2008, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Cape Farewell is a project founded by British artist David Buckland that organizes voyages of scientists, artists and educators into the Arctic to witness the effects of climate change. Through the dialogue of arts and science, the project aims to engage a wider audience in a discussion of the effects of climate change in the north. To date, participating artists include Rachel Whiteread, Brian Jungen, Ian McEwan, Vikram Seth and Antony Gormley.
Last year the British Council in Canada formed a partnership with Cape Farewell to bring the Cape Farewell Youth Expedition 2008 to Canada. It will include students from 15 Canadian high schools (including Porter Creek Secondary School) as well as students from Brazil, Mexico, India, Germany, Ireland and the United Kingdom. Join Martin Rose, as he speaks about the ground-breaking environmental education opportunity being afforded to these youth, and how it fits into the larger framework of Cape Farewell’s thinking on climate change communication through the interplay of arts and science.
Asking the unanswerable question:
Why did stone age people migrate across Beringia?
Jon Turk, Ph.D. Chemistry, Adventure traveler
Sunday, May 4, 2008, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Monday, May 5, 2008, 7:30 pm Kluane National Park VRC, Haines Junction
In 1996, two boys tripped over a skull along the banks of the Columbia River. The skeleton, dubbed Kennewick Man; was about 9,500 years old. Curiously, he was neither Native American nor Caucasoid, but possibly a Jomon, the ancient inhabitants of Japan and relatives of the Polynesians and the Ainu. The best evidence indicates that these people paddled across the North Pacific to cross Beringia as the Ice Age glaciers were receding.
For scientist and adventurer Jon Turk, this discovery raised stunning questions about the early colonization of Beringia. What combination of dreams or necessity drove these hunter-gatherer-mariners to leave their familiar and bountiful climes in ancient Japan, and paddle across the Arctic - during the Ice Age? And how had they succeeded?
Propelled by adventure and curiosity, Jon crossed 3,000 miles of tempestuous oceans in a small open boat, following the Asian coastline from Japan to Alaska's St. Lawrence Island. In a lecture that echoes the classic expedition of Thor Heyerdahl, Jon addresses Stone Age migration, archaeological mysteries, the eternal battle of man versus nature, and our most profound questions about humanity.
A full glacial refugia south of Beringia? - new DNA evidence
Ken Marr, Curator of Botany, Royal BC Museum
Keynote speaker for the Biodiversity Forum
Friday, April 4, 2008, 7:30 pm Yukon College Lecture Hall, Whitehorse
Social to follow
Late Pleistocene ice sheets are thought to have covered most of western Canada, including nearly all of British Columbia. Ken Marr and his team are examining patterns of genetic variation in Arctic-alpine plants to investigate their post-glacial migration routes and to evaluate the possibility of full-glacial refugia within the area covered by the Cordilleran Ice Sheet.
They have recently completed an analysis of DNA variation in Mountain Sorrel (Oxyria digyna). As expected, relatively high genetic diversity was found in samples from eastern Beringia. However, similar levels of genetic diversity were found in northern BC, an unexpected result if British Columbia was entirely covered by ice during the late Pleistocene. These observations suggest the presence of unglaciated areas providing late Pleistocene refugia in northern BC. Such refugia would have important implications for the origins and migrations of other plant and animal species in NW North America. Join Ken as he outlines the nature of his work with molecular markers and shares some of his conclusions.
Tropical China: ethnobotany and crop domestication
Ken Marr, Curator of Botany, Royal BC Museum
Sunday, April 6, 2008, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Monday, April 7, 2008, 7:30 pm Kluane National Park Visitor Reception Centre, Haines Junction
Ethnobotany simply defined is "the use of plants by people". Most commonly we think of medicinal plants, but there are many other types of plant-human interactions, and of these the use of plants for food is probably the most significant. Depending on the time and place, plants used by humans for food were either primarily collected from the wild or were domesticated crops. The place, process and consequences of crop plant domestication are all significant aspects of ethnobotanical research.
From 1997 to 1999, Ken Marr and his wife lived in Yunnan Province in China, hosted by Academia Sinica at the Xishuangbanna Tropical Botanical Garden. While there, Ken Marr studied the origin of the domestication of several Asian melons whose roots were unknown. Yunnan is home to many different ethnic groups and is a place where traditional forms of agriculture continue to be practiced. Join Ken as he talks about his research into the domestication of these fruits in areas of Yunnan, Laos and Nepal, and shares his images of the region.
Hidden changes, visible impacts: permafrost in a warming Yukon
Antoni Lewkowicz, Professor, Department of Geography, University of Ottawa
Sunday, March 2, 2008, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Tuesday, March 4, 2008, 7:30 pm Dawson City Museum, Dawson
Sea ice, glaciers and snow packs are all visibly changing as the climate changes, but what of permafrost, the hidden element of the cryosphere (the areas of the earth where water is frozen)? Slope collapses, crumbling arctic shorelines and subsiding ground are already evident and will likely become more evident in the future. How will these changes affect northern environments and infrastructure projects like the proposed Alaska Highway Gas Pipeline? What are the challenges of predicting these impacts?.
Toni Lewkowicz has been studying permafrost and permafrost-related processes in northern Canada for the past 30 years and is the Principal Investigator on the International Polar Year Project, Thermal State of Permafrost in Canada. Join him as he describes his work in the mountains and lowlands of the Yukon, how it relates to changes in other areas of the north, and how it is affecting Yukoners’ lives.
A Dog’s-Eye View of the World
Stanley Coren, PhD, FRSC
Saturday, February 16, 2008, 7:00 pm YOOP Hall, Dawson
Sunday, February 17, 2008, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Before you can understand a dog’s mind you must know what information is getting into his brain and how the world appears to him. This richly illustrated lecture will allow you to see the world through a dog’s eyes, and also hear and sniff the world the way that he does. Are dogs really colorblind? How does a dog’s hearing differ from ours? What is all that sniffing about?
With answers to questions like this you will also find out why dogs sometimes seem to act in odd and unpredictable ways, why they have difficulty solving certain types of problems, and also discover some little known practical secrets that will allow you to train your own dogs more quickly and efficiently.
**********************************
Stanley Coren will also be offering the following workshop in Whitehorse. Payment and registration are required. Email [email protected] for more details.
The Invisible Leash: Some Alternate Views of Dog Training (a workshop)
Stanley Coren, PhD, FRSC
Monday, February 18, 2008, 7:00 - 10:00 pm Takhini Arena Mezzanine, Whitehorse
Many of the dog training procedures that are still being used in North America are based on the methods employed by the German military and police beginning in the early 1900’s and somewhat modified in the middle of the twentieth century. Our understanding of the theory of dog training has advanced quite a bit since then, however, the actual practices used by many trainers has lagged behind the scientific findings.
This workshop will be divided into two sections. The first will be an illustrated presentation that will give participants an understanding of several different methods of dog training based on the most recent psychological research. The second section will involve some hands on demonstrations using participants and their dogs. Some common behavior and training problems will also be dealt with as time permits.
Ocean Energy for Canada: an economic development opportunity
Chris Knight, Founding Chair, Ocean Renewable Energy Group
Sunday, February 10, 2008, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Monday, February 11, 2008, 7:30 pm Kluane National Park Visitor Reception Centre, Haines Junction
Tidal stream and wave energy harnesses the kinetic energy potential in oceans as well as any moving water. It is renewable and as dependable and predictable as the moon and its relationship with earth. Technology is developing in various parts of the world, but, as yet, there is no dominant technology and no dominant national economy as there has been with wind energy.
Canada has some 40,000 mW of tidal stream energy and 40,000 mW of near shore wave energy. Some of that potential can be used to supply 10% of Canada’s electricity needs and add low-emitting ocean power to it’s clean energy future; use perpetual ocean power to protect consumers from fuel cost risks; replace dirty diesel for remote and northern communities; create jobs as an exporter of ocean energy technology, projects and services to a world market and create wealth as a major supplier of ocean based renewable energy to the US.
Chris Knight’s presentation will trace the evolution of ocean energy development in Canada including sectoral development, technology advances, policy and program initiatives and current project status.
Messages for modern times
– left behind by ice sheets and ice shelves
Dr. John England, Professor & NSERC Northern Research Chair, Earth & Atmospheric Sciences, University of Alberta
Sunday, November 18, 2007, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
John England has been studying glacial and postglacial environmental change across the Canadian Arctic Archipelago for over 40 years. Recent research supported by his NSERC Northern Research Chair has led to new discoveries concerning environmental change at high latitudes. To illustrate this, John will tie together several new themes that his research group is focussing on:
Strange Things Done in the Midnight Sun: Bats at High Latitudes
Jennifer Talerico, MSc Candidate, University of Calgary
Sunday, October 28, 2007, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Monday, October 29, 2007, 7:30 pm Northern Lights Centre, Watson Lake
How do nocturnal animals such as bats survive in the Land of the Midnight Sun? Do they remain nocturnal or start living during the day? Do they behave similarly to bats living at southern latitudes? To examine these questions Jen Talerico is studying the behaviour of little brown bats (Myotis lucifugus) in Watson Lake.
Jen studies bats by capturing them in mist nets, recording their echolocation calls on bat detectors, and recording when they leave from, and return to, their day roost. Join Jen as she shares the findings from her 2006 field season, and puts them in the context of what is known about Yukon bat biology.
Reading environmental change in Yukon lake sediments
Joan Bunbury, Paleoclimatologist, Ph.D. candidate, University of Ottawa
Sunday, September 30, 2007, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Monday, October 1, 2007, 7:30 pm Kluane National Park VRC, Haines Junction
The further you go down through the sediments found in Yukon lakes, the further you go back in time. The physical, chemical, and biological evidence that is preserved in the sediments helps us to understand the history of the lake, the surrounding landscape, and the regional climate.
Join Joan Bunbury for an explanation of how lake sediment cores are collected, the information that is contained in them, and how that information can be used to reconstruct environmental change over the past 10,000 years in the southwest Yukon.
Sandra MacDougall, M.E.Des., Instructor, Red Deer College
Saturday, July 26, 2008, 7:30 pm Kluane National Park VRC, Haines Junction
Sunday, July 27, 2008, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Since 1997, Sandra MacDougall has reviewed many of the reported bear-human interactions along different trails and routes in Kluane National Park and Reserve. In some cases, her work has resulted in changes in park management. Join her as she outlines some of the highlights of her analyses over the years, and explores trends in bear-human interactions in Kluane.
The Eye-in-the-Sky: Changes in Arctic Sea Ice and Climate over the Past 30 Years
Ellsworth LeDrew, Professor of Geography
Sunday, June 1, 2008, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Since 1978, a succession of satellites has been passing over the poles recording specific characteristics of the sea ice and snow cover. Using sensors that can record surface information regardless of cloud cover or existence of sunlight, we have built up an extensive picture of the dramatic change in the polar environment that we now know is linked to the human contribution to global warming. Because of the positive feedbacks between snow/ice and the atmosphere, or the ‘leverage’ effect, the impact of this warming is enhanced in the polar regions. Consequently, what happens in the far north is an early indicator, or ‘canary in the coal mine’ of what might happen to the rest of the world.
Dr. LeDrew will illustrate the dramatic decline of sea ice in the Arctic Basin through a time series of satellite images. As sea routes in the Arctic Basin and the Archipelago are opened, there will be significant implications for Canadian Sovereignty, resource exploration, and people’s way of life. How should Canada and its citizens respond?
Cape Farewell: Art, Climate Change and Youth
Martin Rose, Director of the British Council in Canada
Sunday, May 25, 2008, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Cape Farewell is a project founded by British artist David Buckland that organizes voyages of scientists, artists and educators into the Arctic to witness the effects of climate change. Through the dialogue of arts and science, the project aims to engage a wider audience in a discussion of the effects of climate change in the north. To date, participating artists include Rachel Whiteread, Brian Jungen, Ian McEwan, Vikram Seth and Antony Gormley.
Last year the British Council in Canada formed a partnership with Cape Farewell to bring the Cape Farewell Youth Expedition 2008 to Canada. It will include students from 15 Canadian high schools (including Porter Creek Secondary School) as well as students from Brazil, Mexico, India, Germany, Ireland and the United Kingdom. Join Martin Rose, as he speaks about the ground-breaking environmental education opportunity being afforded to these youth, and how it fits into the larger framework of Cape Farewell’s thinking on climate change communication through the interplay of arts and science.
Asking the unanswerable question:
Why did stone age people migrate across Beringia?
Jon Turk, Ph.D. Chemistry, Adventure traveler
Sunday, May 4, 2008, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Monday, May 5, 2008, 7:30 pm Kluane National Park VRC, Haines Junction
In 1996, two boys tripped over a skull along the banks of the Columbia River. The skeleton, dubbed Kennewick Man; was about 9,500 years old. Curiously, he was neither Native American nor Caucasoid, but possibly a Jomon, the ancient inhabitants of Japan and relatives of the Polynesians and the Ainu. The best evidence indicates that these people paddled across the North Pacific to cross Beringia as the Ice Age glaciers were receding.
For scientist and adventurer Jon Turk, this discovery raised stunning questions about the early colonization of Beringia. What combination of dreams or necessity drove these hunter-gatherer-mariners to leave their familiar and bountiful climes in ancient Japan, and paddle across the Arctic - during the Ice Age? And how had they succeeded?
Propelled by adventure and curiosity, Jon crossed 3,000 miles of tempestuous oceans in a small open boat, following the Asian coastline from Japan to Alaska's St. Lawrence Island. In a lecture that echoes the classic expedition of Thor Heyerdahl, Jon addresses Stone Age migration, archaeological mysteries, the eternal battle of man versus nature, and our most profound questions about humanity.
A full glacial refugia south of Beringia? - new DNA evidence
Ken Marr, Curator of Botany, Royal BC Museum
Keynote speaker for the Biodiversity Forum
Friday, April 4, 2008, 7:30 pm Yukon College Lecture Hall, Whitehorse
Social to follow
Late Pleistocene ice sheets are thought to have covered most of western Canada, including nearly all of British Columbia. Ken Marr and his team are examining patterns of genetic variation in Arctic-alpine plants to investigate their post-glacial migration routes and to evaluate the possibility of full-glacial refugia within the area covered by the Cordilleran Ice Sheet.
They have recently completed an analysis of DNA variation in Mountain Sorrel (Oxyria digyna). As expected, relatively high genetic diversity was found in samples from eastern Beringia. However, similar levels of genetic diversity were found in northern BC, an unexpected result if British Columbia was entirely covered by ice during the late Pleistocene. These observations suggest the presence of unglaciated areas providing late Pleistocene refugia in northern BC. Such refugia would have important implications for the origins and migrations of other plant and animal species in NW North America. Join Ken as he outlines the nature of his work with molecular markers and shares some of his conclusions.
Tropical China: ethnobotany and crop domestication
Ken Marr, Curator of Botany, Royal BC Museum
Sunday, April 6, 2008, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Monday, April 7, 2008, 7:30 pm Kluane National Park Visitor Reception Centre, Haines Junction
Ethnobotany simply defined is "the use of plants by people". Most commonly we think of medicinal plants, but there are many other types of plant-human interactions, and of these the use of plants for food is probably the most significant. Depending on the time and place, plants used by humans for food were either primarily collected from the wild or were domesticated crops. The place, process and consequences of crop plant domestication are all significant aspects of ethnobotanical research.
From 1997 to 1999, Ken Marr and his wife lived in Yunnan Province in China, hosted by Academia Sinica at the Xishuangbanna Tropical Botanical Garden. While there, Ken Marr studied the origin of the domestication of several Asian melons whose roots were unknown. Yunnan is home to many different ethnic groups and is a place where traditional forms of agriculture continue to be practiced. Join Ken as he talks about his research into the domestication of these fruits in areas of Yunnan, Laos and Nepal, and shares his images of the region.
Hidden changes, visible impacts: permafrost in a warming Yukon
Antoni Lewkowicz, Professor, Department of Geography, University of Ottawa
Sunday, March 2, 2008, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Tuesday, March 4, 2008, 7:30 pm Dawson City Museum, Dawson
Sea ice, glaciers and snow packs are all visibly changing as the climate changes, but what of permafrost, the hidden element of the cryosphere (the areas of the earth where water is frozen)? Slope collapses, crumbling arctic shorelines and subsiding ground are already evident and will likely become more evident in the future. How will these changes affect northern environments and infrastructure projects like the proposed Alaska Highway Gas Pipeline? What are the challenges of predicting these impacts?.
Toni Lewkowicz has been studying permafrost and permafrost-related processes in northern Canada for the past 30 years and is the Principal Investigator on the International Polar Year Project, Thermal State of Permafrost in Canada. Join him as he describes his work in the mountains and lowlands of the Yukon, how it relates to changes in other areas of the north, and how it is affecting Yukoners’ lives.
A Dog’s-Eye View of the World
Stanley Coren, PhD, FRSC
Saturday, February 16, 2008, 7:00 pm YOOP Hall, Dawson
Sunday, February 17, 2008, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Before you can understand a dog’s mind you must know what information is getting into his brain and how the world appears to him. This richly illustrated lecture will allow you to see the world through a dog’s eyes, and also hear and sniff the world the way that he does. Are dogs really colorblind? How does a dog’s hearing differ from ours? What is all that sniffing about?
With answers to questions like this you will also find out why dogs sometimes seem to act in odd and unpredictable ways, why they have difficulty solving certain types of problems, and also discover some little known practical secrets that will allow you to train your own dogs more quickly and efficiently.
**********************************
Stanley Coren will also be offering the following workshop in Whitehorse. Payment and registration are required. Email [email protected] for more details.
The Invisible Leash: Some Alternate Views of Dog Training (a workshop)
Stanley Coren, PhD, FRSC
Monday, February 18, 2008, 7:00 - 10:00 pm Takhini Arena Mezzanine, Whitehorse
Many of the dog training procedures that are still being used in North America are based on the methods employed by the German military and police beginning in the early 1900’s and somewhat modified in the middle of the twentieth century. Our understanding of the theory of dog training has advanced quite a bit since then, however, the actual practices used by many trainers has lagged behind the scientific findings.
This workshop will be divided into two sections. The first will be an illustrated presentation that will give participants an understanding of several different methods of dog training based on the most recent psychological research. The second section will involve some hands on demonstrations using participants and their dogs. Some common behavior and training problems will also be dealt with as time permits.
Ocean Energy for Canada: an economic development opportunity
Chris Knight, Founding Chair, Ocean Renewable Energy Group
Sunday, February 10, 2008, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Monday, February 11, 2008, 7:30 pm Kluane National Park Visitor Reception Centre, Haines Junction
Tidal stream and wave energy harnesses the kinetic energy potential in oceans as well as any moving water. It is renewable and as dependable and predictable as the moon and its relationship with earth. Technology is developing in various parts of the world, but, as yet, there is no dominant technology and no dominant national economy as there has been with wind energy.
Canada has some 40,000 mW of tidal stream energy and 40,000 mW of near shore wave energy. Some of that potential can be used to supply 10% of Canada’s electricity needs and add low-emitting ocean power to it’s clean energy future; use perpetual ocean power to protect consumers from fuel cost risks; replace dirty diesel for remote and northern communities; create jobs as an exporter of ocean energy technology, projects and services to a world market and create wealth as a major supplier of ocean based renewable energy to the US.
Chris Knight’s presentation will trace the evolution of ocean energy development in Canada including sectoral development, technology advances, policy and program initiatives and current project status.
Messages for modern times
– left behind by ice sheets and ice shelves
Dr. John England, Professor & NSERC Northern Research Chair, Earth & Atmospheric Sciences, University of Alberta
Sunday, November 18, 2007, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
John England has been studying glacial and postglacial environmental change across the Canadian Arctic Archipelago for over 40 years. Recent research supported by his NSERC Northern Research Chair has led to new discoveries concerning environmental change at high latitudes. To illustrate this, John will tie together several new themes that his research group is focussing on:
- A fundamental reinterpretation of the history of the northwest Laurentide ice Sheet including the northeast limit of Beringia and the resubmergence of the Bering Strait.
- Documentation of a former ice shelf that formed catastrophically during the deglaciation of the northwest Laurentide Ice Sheet, and its relevance to both the demise of the ice sheet and as an analogue for modern day west Antarctica under a warming global climate.
- The recent documentation of the age of the extant sea-ice ice shelves on Ellesmere Island that constitutes the most resistant core of the diminishing modern Arctic Ocean sea ice regime.
Strange Things Done in the Midnight Sun: Bats at High Latitudes
Jennifer Talerico, MSc Candidate, University of Calgary
Sunday, October 28, 2007, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Monday, October 29, 2007, 7:30 pm Northern Lights Centre, Watson Lake
How do nocturnal animals such as bats survive in the Land of the Midnight Sun? Do they remain nocturnal or start living during the day? Do they behave similarly to bats living at southern latitudes? To examine these questions Jen Talerico is studying the behaviour of little brown bats (Myotis lucifugus) in Watson Lake.
Jen studies bats by capturing them in mist nets, recording their echolocation calls on bat detectors, and recording when they leave from, and return to, their day roost. Join Jen as she shares the findings from her 2006 field season, and puts them in the context of what is known about Yukon bat biology.
Reading environmental change in Yukon lake sediments
Joan Bunbury, Paleoclimatologist, Ph.D. candidate, University of Ottawa
Sunday, September 30, 2007, 7:30 pm Yukon Beringia Interpretive Centre, Whitehorse
Monday, October 1, 2007, 7:30 pm Kluane National Park VRC, Haines Junction
The further you go down through the sediments found in Yukon lakes, the further you go back in time. The physical, chemical, and biological evidence that is preserved in the sediments helps us to understand the history of the lake, the surrounding landscape, and the regional climate.
Join Joan Bunbury for an explanation of how lake sediment cores are collected, the information that is contained in them, and how that information can be used to reconstruct environmental change over the past 10,000 years in the southwest Yukon.