DOCSLIB.ORG

Comparison of Genetic Diversity Between Chum and Coho Salmon in the Yukon River Potential Impacts of Land-Use Activities

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Comparison of Genetic Diversity Between Chum and Coho Salmon in the Yukon River Potential Impacts of Land-Use Activities U.S. Fish & Wildlife Service Comparison of Genetic Diversity between Chum and Coho Salmon in the Yukon River Potential Impacts of Land-Use Activities Introduction Alaska Tanana River System Loss of freshwater habitat is a common factor associated with the decline Yukon River in abundance and genetic diversity of Pacific salmon throughout their range. The impact of localized habitat degradation on genetic diversity may vary among species depending on how populations are structured. Species 200km composed of populations that occupy large geographic regions and exhibit moderate to high levels of genetic exchange are less likely to lose genetic Innoko River System diversity as a result of local habitat Species System Tributary LS Year N Chum Salmon Innoko R California Cr. A 1997 52 degradation than those composed Tolstoi Cr. A 1997 50 of isolated populations occurring Tanana R. Chena R. A 1997 57 on small geographic scales with low Salcha R. A 1997 50 rates of genetic exchange. Therefore, species-specific population structure Coho Salmon Innoko R. Illinois Cr. J 1997 78 is a critical factor in assessment of the California Cr. J 1996 84 potential loss to genetic diversity for a Tanana R. Nenana R. A 1997 56 Clearwater Cr. A 1997 56 given species when habitat is impacted by land-use activities (e.g., mining, logging, development). Figure 1. Map of sampling areas in the Yukon River drainage. The Conservation Genetics Laboratory of the U.S. Fish and Wildlife populations of coho salmon have used microsatellites and mitochondrial Service, Alaska Region, initiated a been detected at both small and large DNA (mtDNA) to estimate the degree study to examine genetic diversity geographic scales in river systems of of population structure within and and population structure of chum the Pacific Northwest and Alaska. In among the four collections made for (Oncorhynchus keta) and coho (O. this study, we test the hypothesis that each species. kisutch) salmon that co-occur in the chum and coho salmon in the Yukon Innoko and Tanana Rivers, tributaries River exhibit population structure The statistic FST is a relative of the Yukon River in Alaska at different spatial scales. If this measure of population structure (Figure 1). This study was part of a hypothesis is true, then the risk of ranging between zero (no population comprehensive assessment designed losing genetic diversity because of structure) and one (completely to evaluate the possible environmental localized habitat degradation in the isolated populations). This statistic and biological impacts of a gold mine Yukon River drainage could differ was used to quantify the amount on a Yukon River tributary near the between these species. of genetic variation resulting from Innoko National Wildlife Refuge. population divergence. Variation Methods was hierarchically partitioned into Previous genetic analyses indicate that three components: 1) among all chum salmon populations, with some Fin tissue samples (non-lethal) were eight collections; 2) between the two exceptions, appear to be organized on collected (1996 and 1997) from chum tributary collections within each of large geographic scales encompassing and coho salmon in both the Innoko and the two rivers, and 3) between the two multiple river systems. In contrast, Tanana River tributaries (Figure 1). We rivers. Conservation Genetics Laboratory - Alaska Region Results Among Between Between All Rivers Tributaries Our study indicates that genetic diversity Within is structured at different spatial scales Collections for chum and coho salmon in the Yukon Rivers River (Figure 2). Genetic diversity in Yukon River chum salmon appears to be distributed over a relatively broad Chum geographic area. The estimate of Microsatellites overall population structure from the 0.021 0.021 0.000 microsatellite loci (FST = 0.021) while significant, is low, and due entirely to genetic differences between the two rivers and not to genetic differences within rivers (i.e., between tributaries). This large-scale population structure mtDNA 0.000 0.000 0.000 should serve to buffer chum salmon from the loss of genetic diversity if some spawning aggregations are lost because of localized habitat degradation. However, it must be emphasized that Coho regardless of whether or not overall genetic diversity is lost, the loss of Microsatellites 0.091 0.061 0.032 chum salmon from a tributary would likely reduce the overall abundance of Yukon River chum salmon. Such a loss would have other negative impacts (e.g. ecological, cultural, or economic). mtDNA 0.586 0.564 0.052 In contrast, the data indicate that coho salmon collections in the Yukon River are highly differentiated, suggesting that population structure occurs on a No Completely much smaller geographic scale than for Population Isolated chum salmon (Figure 2). Because coho Structure Populations salmon populations are relatively small and discrete, the likelihood of localized Key F Value 0.000 0.500 1.000 habitat degradation affecting an entire ST population is greater with coho salmon than with chum salmon. It appears that gene flow between populations is Figure 2. Genetic diversity comparisions for chum and coho salmon in extremely low and, if exterminated, Yukon River tributaries. the vacant habitat is unlikely to be re- colonized rapidly by other coho salmon populations. such as mining in the Innoko River conservation plans may be required to drainage, would impact the genetic maintain genetic diversity of salmon Conclusions diversity of coho salmon to a much species occupying the same geographic greater degree than chum salmon. area. Thus, a multi-species approach is This study suggests that habitat Similarly, the geographic scale of recommended for evaluating the potential degradation resulting from land-use management units will differ between impact of localized habitat degradation on activities in the Yukon River drainage, these two species. Species-specific the genetic diversity of Pacific salmon. For additional details, see: For more information contact: Olsen JB, Spearman WJ, Sage GK, Jeff Olsen Miller SJ, Flannery B, Wenburg JK U.S. Fish and Wildlife Service (2004) Variation in the population Conservation Genetics Laboratory structure of Yukon River chum and 1011 E. Tudor Road coho salmon: evaluating the potential Anchorage, Alaska 99503 impact of localized habitat degradation. 907/786 3598 Transactions of the American Fisheries [email protected] Society 133, 476-483. alaska.fws.gov/fisheries/genetics November 2010 .
Load more

Recommended publications
  • Summary Report for the Navigability of the Nabesna River Within the Tanana River Region, Alaska
    United States Departmentof the Interior BUREAU OF LAND MANAGEMENT TAKE PRIDE • Alaska State Office '"AMERICA 222 West Seventh Avenue, #13 Anchorage, Alaska 99513-7504 http://www.blm.gov/ak In Reply Refer to: 1864 (AK9410) Memorandum To: File FF-094614 From: Jack Frost, Navigable Waters Specialist (AK9410) Subject: Summary Report for the Navigability of the Nabesna River within the Tanana River Region, Alaska The State of Alaska (State) filed an application, dated October 3, 2005, for a recordable disclaimer of interest (RDI) for lands underlying the Nabesna River "between the ordinary high water lines of the left and right banks from its origins at the Nabesna Glacier within Township 5 North, Ranges 13 and 14 East, Copper River Meridian, Alaska, downstream to its confluence with the Tanana River in Township 15 North, Range 19 East, Copper River Meridian." 1 The State identified the location of its application on two maps entitled "Nabesna River Recordable Disclaimer of Interest Application," dated October 3, 2005. The maps were submitted with the State's application. The State filed an amended RDI application for the Nabesna River, dated September 16, 2015, "to include only the submerged lands underlying the Nabesna River from its mouth to the Black Hills (Sec. 25, TI IN, Rl 7E, and CRM). The State withdraws its request for an RDI on the submerged lands underlying the Nabesna River from Sec. 25, Tl IN, R17E, CRM and the river's source at the Nabesna Glacier." 2 Clarifying its letter from September 16, 2015, the State submitted an email on October 16, 2015 stating that "the State withdraws its request for an RDI on the submerged lands underlying the Nabesna River from its confluence with the Cheslina River in Section 35, Tl2N, RI 7E, CRM upstream to the river's source at the Nabesna Glacier." 3 The State bases its application for a disclaimer of interest on the Equal Footing Doctrine, the Submerged Lands Act of May 22, 1953, the Alaska Statehood Act, the Submerged Lands Act of 1988, and any other legally cognizable reason.
    [Show full text]
  • Roadside Salmon Fishing in the Tanana River Drainage
    oadside Salmon Fishing R in the Tanana River Drainage Table of Contents Welcome to Interior Alaska ..........................................................................1 Salmon Biology ...................................................................................................1 Best Places to Fish for King and Chum Salmon ................................................2 Chena River ...............................................................................................2 Salcha River ...............................................................................................3 Other King and Chum Salmon Fisheries .............................................3 Where Can I Catch Coho Salmon? ...............................................................4 cover and front inside photos by: Reed Morisky & Audra Brase The Alaska Department of Fish and Game (ADF&G) administers all programs and activities free from discrimination based on race, color, national origin, age, sex, religion, marital status, pregnancy, parenthood, or disability. The department administers all programs and activities in compliance with Title VI of the Civil Rights Act of 1964, Section 504 of the Rehabilitation Act of 1973, Title II of the Ameri- cans with Disabilities Act (ADA) of 1990, the Age Discrimination Act of 1975, and Title IX of the Education Amendments of 1972. If you believe you have been discriminated against in any program, activity, or facility please write: ADF&G ADA Coordinator, P.O. Box 115526, Juneau, AK 99811-5526 U.S. Fish
    [Show full text]
  • Tanana Lakes Recreation Area Master Plan Fairbanks North Star Borough Department of Parks & Recreation
    Tanana Lakes Recreation Area Master Plan Fairbanks North Star Borough Department of Parks & Recreation Tanana Lakes Recreation Area Master Plan 2007 Planning Team: Fairbanks North Star Borough, Department of Parks & Recreation USKH, Inc. FNSB - Department of Parks and Recreation Executive Summary This Master Plan outlines the Fairbanks North Star Borough’s (FNSB’s) plan for the future development and use of the Tanana Lakes Recreation Area, a 750-acre multi-use park south of the City of Fairbanks along the Tanana River. The purpose of the Master Plan is to provide the FNSB with a long-term, planning guide for gravel extraction and development of the recreation area based on resource opportunities and constraints, development opportunities and constraints, and public needs. The Master Plan details the planning purpose and process, existing site conditions and land use, resources assessment, public process and demand, development plan, maintenance and operations considerations, and permits and authorizations required for development of the recreation area. The project concept originated approximately 15 years ago by the FNSB and its need to extract gravel for use at the South Cushman Landfill. The unsecured site has historically been a common place for illegal dumping of junk or abandoned vehicles and other refuse, as well as other unauthorized and criminal activities. Passing years have brought to the forefront the desire to clean up the site in order to enhance the wildlife habitat and natural features of the area in conjunction with the FNSB’s plan to extract gravel. As a result, this Master Plan has become a priority driven by both public safety and the importance of establishing this area for the community’s use and enjoyment.
    [Show full text]
  • North Pole Road/Rail Crossing Reduction Project
    Scoping Summary Report North Pole Road/Rail Crossing Reduction Project May 2011 SCOPING SUMMARY REPORT NORTH POLE ROAD/RAIL CROSSING REDUCTION PROJECT NORTH POLE, ALASKA Prepared for: Alaska Railroad Corporation 327 West Ship Creek Avenue Anchorage, Alaska 99501 Prepared by: DOWL HKM 4041 B Street Anchorage, Alaska 99503 (907) 562-2000 W.O. 60432 May 2011 Scoping Summary Report North Pole, Alaska North Pole Road/Rail Crossing Reduction Project W.O. 60432 TABLE OF CONTENTS Page 1.0 INTRODUCTION ...............................................................................................................1 1.1 General ..............................................................................................................................1 1.2 Project Team .....................................................................................................................2 1.3 Public and Agency Outreach Methods .............................................................................2 1.3.1 Mailing List of Potentially Affected Interests ............................................................3 1.3.2 Informational Flyer/Meeting Announcement .............................................................3 1.3.3 Advertisements ...........................................................................................................3 1.3.4 Project Website ...........................................................................................................4 1.3.5 Project E-Mail Address ...............................................................................................4
    [Show full text]
  • Technical Report 01-05: Fish Habitats and Use in the Tanana River
    Technical Report No. 01-05 Fish Habitats and Use in the Tanana River Floodplain near Big Delta, Alaska, 1999-2000 by James D. Durst June 2001 Alaska Department of Fish and Game Habitat and Restoration Division 1 Tanana Floodplain Fish Habitat Use Technical Report No. 01-05 Fish Habitats and Use in the Tanana River Floodplain near Big Delta, Alaska, 1999-2000 by James D. Durst Technical Report No. 01-05 Kenton P. Taylor Director Habitat and Restoration Division Alaska Department of Fish and Game P.O. Box 25526 Juneau Alaska 99802-5526 June 2001 2 Tanana Floodplain Fish Habitat Use Technical Report No. 01-05 TABLE OF CONTENTS ABSTRACT ........................................................................................ iv INTRODUCTION ................................................................................. 1 ACKNOWLEDGEMENTS ................................................................... 2 STUDY AREA ..................................................................................... 2 METHODS .......................................................................................... 3 Water Quality and Habitat Characteristics ..................................... 5 Fish Sampling and Observations ................................................... 5 Data Analyses ................................................................................ 6 Habitat Sensitivity and Forest Practices ......................................... 6 RESULTS ...........................................................................................
    [Show full text]
  • IWR No. 92 HYDROMETEOROLOGICAL
    Hydrometeorological Literature Review for the Delta-Clearwater Creek Area Item Type Technical Report Authors Fox, John D. Publisher University of Alaska, Institute of Water Resources Download date 27/09/2021 21:23:01 Link to Item http://hdl.handle.net/11122/1438 HYDROMETEOROLOGICAL LITERATURE REVIEW FOR THE DELTA-CLEARWATER CREEK AREA Completion Report State of Alaska Department of Natural Resources Reimbursable Service Agreement Dated August 19, 1977 by John D. Fox Assistant Professor of Land Resources Institute of Water Resources University of Alaska Fairbanks, Alaska 99701 IWR No. 92 June, 1978 ACKNOWLEDGMENT The author wishes to express appreciation to Margo Paine of the Alaska Division of Lands for her cooperation and patience; D. Wilcox and Gordon Nelson of the U. S. Geological Survey for their cooperation and informative conversations; Robert Van Veldhuizen who helped wade through the computer printouts. This project and report were supported through a contract from the State of Alaska, Department of Natural Resources. i i TABLE OF CONTENTS Page ACKNOWLEDGMENT . i i LIST OF FIGURES. iv LIST OF TABLES . iv INTRODUCTION .. 1 SECTION 1: LITERATURE SEARCH. 2 BRIEF SUMMARY OF LITERATURE SEARCH. 2 Meteorological ICl imatologi ca 1 Data . 2 Hydrologic Data--Surface Quality and Quantity. 2 Hydrologic Data--Groundwater 4 ANNOTATED BIBLIOGRAPHY ..•.. 5 APPENDIX TO SECTION 1. ..... 19 SECTION 2: PRELIMINARY ANALYSES 21 LOCAL WATER BALANCE .... 21 Watershed Water Balance. 21 Field Water Balance. 33 GROUNDWATER REGIME .•... 37 General . 37 Clearwater Creek Area. 3B POLLUTANT TRANSPORT .... 40 ASSESSMENT AND RECOMMENDATIONS. 44 Precipitation and Temperature. 44 Wind Speed and Direction .... 44 Streamflow Quantity and Quality. 45 Groundwater...
    [Show full text]
  • Alaska Park Science Anchorage, Alaska
    National Park Service U.S. Department of Interior Alaska Regional Office Alaska Park Science Anchorage, Alaska PROCEEDINGS OF THE CentrCentralal AlaskAlaskaa PParkark SciencSciencee SymposiumSymposium SeptemberSeptember 12-14,12-14, 2006 2006 Denali Park, Alaska Volume 6, Issue 2 Parks featured in this Table of Contents issue of Alaska Park Science Keynote Address Alaska Parks in a Warming Climate: Conserving a Changing Future __________________________ 6 S K A Yukon-Charley Rivers Synthesis L A National Preserve Crossing Boundaries in Changing Environment: Norton Sound A A Synthesis __________________________________________12 Monitoring a Changing Climate Denali National Park and Preserve Long-term Air Quality Monitoring Wrangell-St. Elias in Denali National Park and Preserve __________________18 National Park and Preserve Monitoring Seasonal and Long-term Climate Changes and Extremes in the Central Alaska Network__________ 22 Physical Environment and Sciences Glacier Monitoring in Denali National Park and Preserve ________________________________________26 Applications of the Soil-Ecological Survey of Denali National Park and Preserve__________________31 Bristol Bay Gulf of Alaska Using Radiocarbon to Detect Change in Ecosystem Carbon Cycling in Response to Permafrost Thawing____34 A Baseline Study of Permafrost in the Toklat Basin, Denali National Park and Preserve ____________________37 Dinosauria and Fossil Aves Footprints from the Lower Cantwell Formation (latest Cretaceous), Denali National Park and Preserve ____________________41
    [Show full text]
  • Advisory Announcement
    Division of Commercial Fisheries Alaska Department of Fish and Game Sam Rabung, Director Doug Vincent-Lang, Commissioner Headquarters Office PO Box 115526 PO Box 115526 Juneau, AK 99811-5526 Juneau, AK 99811-5526 www.adfg.alaska.gov Advisory Announcement CONTACT: Jeff Estensen, Area Management Biologist Released: August 28, 2020 (907) 459-7274 Toll free fishing schedule and counts: (866) 479-7387 In Fairbanks fishing schedule hotline: 459-7387 2020 Yukon River Salmon Fall Fishery Announcement #19 Subdistricts 6-A, 6-B and Subdistrict 5-A Subsistence Fishing Districts Affected: Upper Yukon Area Subsistence fishing for fall chum salmon remains closed within the entire Yukon Area because the 2020 fall chum salmon run projection remains below the 300,000 fish needed to allow subsistence fishing following the Yukon River Fall Chum Salmon Management Plan. To provide more subsistence fishing opportunity on fish bound for the Tanana River, subsistence fishermen may use selective gear (live-release (manned) fish wheels and dip nets) to target other salmon and non-salmon fish species. All fall chum salmon caught using the selective gear must be released alive immediately and bypass any livebox on a fish wheel. Dip net mesh size is restricted to 4.5-inch or smaller, with a frame 5 feet or smaller between the two farthest points. Fish wheels are encouraged to be “fish-friendly” to include basket sides and bottoms made of a soft material like seine web; and a padded chute to return fall chum salmon to the water immediately. Subsistence Management Actions Subdistricts 6-A, 6-B and Old Minto Area (from the mouth of the Tanana River upstream to the Wood River, including Manley, Minto, and Nenana), Kantishna River, and Subdistrict 5-A (Tanana): Subsistence salmon fishing is closed until further notice.
    [Show full text]
  • Multiple Crossings of a Large Glacial River by Canada Lynx (Lynx
    80 THE CANADIAN FIELD -N ATURALIST Vol. 128 Multiple Crossings of a Large Glacial River by Canada Lynx ( Lynx canadensis ) DASHIELL FEIERABEND 1, 3 and KNUT KIELLAND 1, 2 1Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, Alaska 99775 USA 2Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska 99775 USA 3Corresponding author: [email protected] Feierabend, Dashiell, and Knut Kielland. 2014. Multiple crossings of a large glacial river by Canada Lynx ( Lynx canadensis ). Canadian Field-Naturalist 128(1): 80 –83. Rivers may act as barriers to the movement of terrestrial mammals, which could limit dispersal and gene flow. Glacial rivers are particularly hazardous because of the cold water temperature and swift current. Yet, we determined that 2 Canada Lynx ( Lynx canadensis ) equipped with GPS collars repeatedly swam across the main channel of the Tanana River in interior Alaska in 2011 as late in the season as November, when the average minimum daily air temperature was −27°C. These observations are consistent with the low level of genetic structure observed in Canada Lynx in northwestern North America and suggest that even large rivers may pose less of a barrier to movement by Canada Lynx than expected. Key Words: barrier; boreal forests; Canada Lynx; Lynx canadensis ; dispersal; home range; river; Alaska Introduction Black Spruce ( Picea mariana ), White Spruce ( Picea Rivers may act as barriers to the movement of ter - glauca ), Balsam Poplar ( Populus balsamifera ), mixed restrial mammals because of the risk of injury or death White Spruce–Alaska Paper Birch ( Betula neoalas - from drowning (Storm et al . 1976; Peres et al .
    [Show full text]
  • Lower Tanana River Drainage
    TANANA RIVER DRAINAGE - GENERAL REGULATIONS 22 Lower Tanana River drainage DALTON HWY Tolovana R. Livengood Yukon River Drainage Yukon River Drainage r Tatalina R. See pages 20 - 21 See pages 20 - 21 ve Ri r Miles Chatanika Riverive n R 0 10 20 ko STEESE HWY Yu ELLIOTT HWYMinto Chena Tanana Hot Springs a Chen Manley Minto Fairbanks Hot Springs r. Flats C m er A N A G rea Ri v A N o l dst T ha I V Harding lc R E R a L. S Nenana Piledriver Slough Birch L. r e v i Dune L. Goodpaster R. R 5 Mile Clearwater a Creek Koole Kuskokwim - Goodnews n h L. Delta River Drainages s Nenana River i r Junction RICHARDSON HWY See pages 12 - 15 t e Healy ALASKA HWY n Delta River a v K i R t Lake a l Minchumina k o Otto Lake T L. Minchumina Upper Copper and Upper Susitna Cantwell River Drainages DENALI HWY See pages 28 - 36 Brushkana Creek PARKS HWY TRANS-ALASKA PIPELINE CORRIDOR Upper Tanana River drainage r er Rive Ta iv aster na R Goodp na ha R c i Sal k v e e e r r C Quartz Lake Yukon River Drainage ALASK A HWY Shaw See pages 20 - 21 C Volkmar Lake A A Koole Lake L N Richardson A A Clearwater Delta Delta Clearwater River S River Junction K D Rainbow Lake A A . D George R T Lake Y S Lake W W O H D Dot Lake R A E O M L Dry Creek Y A T D COAL MINE e l RD.
    [Show full text]
  • Soil Survey of Upper Tanana Area, Alaska Upper Tanana Soil Survey Area
    United States Department of Agriculture, Natural Resources Conservation Service Soil Survey of In cooperation with the University of Alaska Fairbanks Upper Tanana Agricultural and Forestry Experiment Station, and the State of Alaska Department of Natural Resources Area, Alaska This soil survey is a publication of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture (USDA) and other Federal agencies, State agencies, and local agencies. The Natural Resources Conservation Service (NRCS) (formerly the Soil Conservation Service) has leadership for the Federal part of the National Cooperative Soil Survey. Major fieldwork for this soil survey was completed in 1982. Soil names and descriptions were approved in 1986. Unless otherwise indicated, statements in this publication refer to conditions in the Survey Area in 1982. This survey was made cooperatively by the Natural Resources Conservation Service, the University of Alaska Fairbanks Agricultural and Forestry Experiment Station, and the State of Alaska Department of Natural Resources. It is part of the technical assistance furnished to the Salcha-Big Delta Soil and Water Conservation District. Soil maps in this survey may be copied without permission. However, enlargement of these maps could cause misunderstanding of the detail of mapping. If enlarged, maps do not show the small areas of contrasting soils that could have been shown at a larger scale. USDA prohibits discrimination in all its programs and activities on the basis of race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, or marital or family status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720- 2600 (voice and TDD).
    [Show full text]
  • The Concept of Geolinguistic Conservatism in Na-Dene Prehistory
    194 Anthropological Papers of the University of Alaska 2010. The Concept of Geolinguistic Conservatism in Na-Dene Prehistory. IN The Dene-Yeniseian Connection, ed. by J. Kari and B. Potter. Anthropological Papers of the University of Alaska. New Series, vol 5:194-222. with corrections in 2011 THE CONCEPT OF GEOLINGUISTIC CONSERVATISM IN NA-DENE PREHISTORY James Kari Alaska Native Language Center University of Alaska Fairbanks 1.0. INTRODUCTION1 These papers are the first forum on the implications of the Dene-Yeniseian language stock, and in this article I attempt to engage scholars and intellectuals of varying backgrounds and in several disciplines. I have had the privilege of working with of many of the foremost Alaska Athabascan intellectuals for over 35 years. On many occasions I have heard elders state that Athabascan people have lived in Alaska for more than 10,000 years. Perhaps few of these Athabascan elders would be able to parse the technical articles in this collection, but we are certain that many of their descendents will be among the first readers of these articles. At the February 2008 Dene-Yeniseic Symposium the implications of the geography of the proposed Dene-Yenisiean language stock were one topic of discussion. Johanna Nichols commented that the amount of evidence for Dene-Yeniseian is too large to have the antiquity of more than 10,000 years that is implied for an eastward land-based movement of the Na-Dene branch through Beringia. Nichols added that perhaps unless it can be shown that the Na-Dene and Yeniseian languages have changed at a much slower rate than most languages do.
    [Show full text]