TY - JOUR
T1 - Narrow thermal tolerance and low dispersal drive higher speciation in tropical mountains
AU - Polato, Nicholas R.
AU - Gill, Brian A.
AU - Shah, Alisha A.
AU - Gray, Miranda M.
AU - Casner, Kayce L.
AU - Barthelet, Antoine
AU - Messer, Philipp W.
AU - Simmons, Mark P.
AU - Guayasamin, Juan M.
AU - Encalada, Andrea C.
AU - Kondratieff, Boris C.
AU - Flecker, Alexander S.
AU - Thomas, Steven A.
AU - Ghalambor, Cameron K.
AU - Poff, N. Leroy
AU - Funk, W. Chris
AU - Zamudio, Kelly R.
N1 - Funding Information:
ACKNOWLEDGMENTS. We thank D. G. Gannon, José Schreckinger, Maja Celiscak, and numerous student interns for field and laboratory assistance, Amy McMahon for insect illustrations, and Andrea Landeira-Dabarca for stream temperature data. This research was supported by National Science Foundation (NSF) Dimensions of Biodiversity Grants DEB-1046408, DEB-1045960, and DEB-1045991; NSF Graduate Research Fellowships (to B.A.G. and A.A.S.); and the Atkinson Center for a Sustainable Future. Collection permits and field site access were granted by the US Department of Interior National Park Service (Permit ROMO-2011-SCI-0042); the Continental Divide Research Learning Center, US Department of Agriculture Forest Service (Authorization ID: CAN440); Ministerio de Ambiente de Ecuador (Permits 56-IC-FAU/FLO-DPN/ MA and MAE-DNB-CM-2015-0017); the Cayambe-Coca Ecological Reserve; and the residents of Oyacachi.
Funding Information:
We thank D. G. Gannon, José Schreckinger, Maja Celiscak, and numerous student interns for field and laboratory assistance, Amy McMahon for insect illustrations, and Andrea Landeira-Dabarca for stream temperature data. This research was supported by National Science Foundation (NSF) Dimensions of Biodiversity Grants DEB-1046408, DEB-1045960, and DEB-1045991; NSF Graduate Research Fellowships (to B.A.G. and A.A.S.); and the Atkinson Center for a Sustainable Future. Collection permits and field site access were granted by the US Department of Interior National Park Service (Permit ROMO-2011-SCI-0042); the Continental Divide Research Learning Center, US Department of Agriculture Forest Service (Authorization ID: CAN440); Ministerio de Ambiente de Ecuador (Permits 56-IC-FAU/FLO-DPN/ MA and MAE-DNB-CM-2015-0017); the Cayambe-Coca Ecological Reserve; and the residents of Oyacachi.
Publisher Copyright:
© 2018 National Academy of Sciences. All rights reserved.
PY - 2018/12/4
Y1 - 2018/12/4
N2 - Species richness is greatest in the tropics, and much of this diversity is concentrated in mountains. Janzen proposed that reduced seasonal temperature variation selects for narrower thermal tolerances and limited dispersal along tropical elevation gradients [Janzen DH (1967) Am Nat 101:233–249]. These locally adapted traits should, in turn, promote reproductive isolation and higher speciation rates in tropical mountains compared with temperate ones. Here, we show that tropical and temperate montane stream insects have diverged in thermal tolerance and dispersal capacity, two key traits that are drivers of isolation in montane populations. Tropical species in each of three insect clades have markedly narrower thermal tolerances and lower dispersal than temperate species, resulting in significantly greater population divergence, higher cryptic diversity, higher tropical speciation rates, and greater accumulation of species over time. Our study also indicates that tropical montane species, with narrower thermal tolerance and reduced dispersal ability, will be especially vulnerable to rapid climate change.
AB - Species richness is greatest in the tropics, and much of this diversity is concentrated in mountains. Janzen proposed that reduced seasonal temperature variation selects for narrower thermal tolerances and limited dispersal along tropical elevation gradients [Janzen DH (1967) Am Nat 101:233–249]. These locally adapted traits should, in turn, promote reproductive isolation and higher speciation rates in tropical mountains compared with temperate ones. Here, we show that tropical and temperate montane stream insects have diverged in thermal tolerance and dispersal capacity, two key traits that are drivers of isolation in montane populations. Tropical species in each of three insect clades have markedly narrower thermal tolerances and lower dispersal than temperate species, resulting in significantly greater population divergence, higher cryptic diversity, higher tropical speciation rates, and greater accumulation of species over time. Our study also indicates that tropical montane species, with narrower thermal tolerance and reduced dispersal ability, will be especially vulnerable to rapid climate change.
KW - Climate variability
KW - Cryptic diversity
KW - Elevation gradient
KW - Speciation
KW - Thermal tolerance
UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85057631434&origin=resultslist&sort=plf-f&src=s&st1=10.1073%2fpnas.1809326115&st2=&sid=10a34004777a97edd490294112f48f04&sot=b&sdt=b&sl=28&s=DOI%2810.1073%2fpnas.1809326115%29&relpos=0&citeCnt=3&searchTerm=#
UR - http://www.mendeley.com/research/narrow-thermal-tolerance-low-dispersal-drive-higher-speciation-tropical-mountains
U2 - 10.1073/pnas.1809326115
DO - 10.1073/pnas.1809326115
M3 - Article
C2 - 30397141
SN - 0027-8424
VL - 115
SP - 12471
EP - 12476
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 49
ER -
