keynote lecture at grand valley state university student scholars day
TRANSCRIPT
Models of extinction from the Miocene to the last 40 years
Liliana M. Dávalos
Grand Valley State University12 April 2017
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Most important scientific discovery of the 18th century
Lightning as electricity? c. 1751
Conservation of mass? c. 1789
Georges Cuvier
Mass extinction! Sepkoski 1984 Paleobiology
65 million years ago looks fine © Karen Carr/Australian Museum
Until you look closely © National Geographic
The best of times Sepkoski 1984 Paleobiology
The worst of times Ceballos et al. 2015 Sci. Adv.
John James Audubon
When did it start? FAO 2012 State of the World’s Forests
NOAA
International Fertilizer Industry Association
Chauvet, 35K years ago © Stephen Alvarez/National Geographic
Here in the New World 14.5K years ago © Velizar Simeonovski/Field Museum
Halligan et al. 2016 Sci. Adv.
But 12.5K years ago
© Ron Blakey/Northern Arizona University © Illinois State Museum
The mystery of the giants
• End glaciation ~11.7K years ago
• Mastodon, ground sloths, extinct around this time
• Human hunting before that date
• What or who killed these giants?
© PBS
Mammals of the Caribbean
© Yomangani/Creative Commons © Eladio Fernandez
© Jon Flanders
More mammals of the Caribbean!
© Ghedoghedo
Rosenberger et al. 2010 Proc. R. Soc. Lond. B © Adrian Tejedor
Enter the bats of the Caribbean Dominican Republic 2014
Why did so many bats go extinct? Deglaciation!
© Adrian Tejedor
Islands of the Caribbean: The West Indies
Dávalos,& Turvey 2012 Bones, Clones, and Biomes
Trouble is we didn’t have the dates
Soto-Centeno & Steadman 2015 Sci. Rep.
A plan of action
• Hundreds of mammals• Dozens of islands • When did mammals
go extinct?• When did humans
arrive?
©Theodor de Bry/National Library of Medicine
• Cooke, Dávalos et al. 2018 Annu. Rev. Ecol. Evol. Syst.
Timing is everything Cooke, Dávalos et al. 2018 Annu. Rev. Ecol. Evol. Syst.
Cooke, Dávalos et al. 2018 Annu. Rev. Ecol. Evol. Syst.
Statistical models
• Fauna and humans overlap• Extinction by
humans possible• No fauna and human
overlap• Extinction not by
humans
How did the mammals of the Caribbean go extinct?
One size does not fit all
Larger mammals probably hunted early on
© Ghedoghedo Wilson 1989 J Field Archaeol.
Many extinction events recorded after arrival of Old World invasive competitors/predators
Turvey et al. 2012 Mamm. Biol.
© Adrian Tejedor ©Pierpont Morgan Library
Survivors are special Cooke, Dávalos et al. 2017 Annu. Rev. Ecol. Evol. Syst.
On extinction
• No single cause• Before humans
• Deglaciation• Area loss
• After humans• Hunting• Ecosystem change• Invasive species
Photo by Jon Flanders
We are here Ceballos et al. 2015 Sci. Adv.
Biodiversity is concentrated Fjeldså, Álvarez et al. 2005 Ambio
Davalos et al. 2011 Env. Sci. Tech.Forest loss from illegal
markets
Answering a question for the UN The Special Session of 2016
A matter of time
• Were illegal markets the start of deforestation?
• If not, how did deforestation begin?
Etter et al. 2008 Ann. Assoc. Am. Geogr.
Opening the frontier Denevan 1966 Geogr. Rev.
Roads and colonization projects
Brücher 1977 Geogr. Z. Schuurman 1978 Tijdschr. Econ. Soc. Ge.
Brazil
Bolivia
Peru
Colombia
Ecuador
Coca cultivation
Government-sponsored
before 1979
1990/1992
Projects
Coca cultivation
Percent forest
a b
Location of projects relates to carbon emissions Harris et al. 2012 Science
Brazil
Bolivia
Peru
Colombia
Ecuador
Coca cultivation
Government-sponsored
before 1979
1990/1992
Projects
Coca cultivation
High
Low
2014
Percent forest Probability of coca
a b c
A remarkable spatial pattern Davalos et al. 2016 Bioscience
High
Low
Probability of coca
c
Time to model
• Measure influence of the development projects• If projects set the
stage for illicit crops• Distance from
projects should decrease probability of crops
Davalos et al. 2016 Bioscience
The model helps us understand recent history Davalos et al. 2016 Bioscience
© UNODC
On forest loss
• Incomplete development has consequences
• Roads transform the landscape
• Roads are needed anyhow• Protect forests
• Parks, easements
A simple model based on fire Armenteras… Dávalos 2017 Ecol. Appl.
Thanks!