Estimating paleoenvironments using ecological niche models of nearest living relatives: A case study of Eocene Aesculus L.

Abstract

Past climates experienced by fossil plant species have often been inferred based on the environmental requirements of their evolutionarily nearest living relatives (NLR). Here we have combined paleoclimatic estimation using NLRs with ecolological niche modeling (ENM) and have demonstrated the combined approach by inferring the Eocene environment of Aesculus L. (Hippocastanoideae, Sapindaceae), a genus of woody eudicots with extant species generally preferring temperate climates. Specifically, we applied ENM‐NLR to four Eocene floras in which Aesculus fossils are known to occur: McAbee and Princeton (British Columbia), Republic (Washington State), and Spitsbergen (European Arctic Circle). Additionally, we used ENM‐NLR to estimate whether paleoenvironmental conditions were suitable for Aesculus at a fifth flora, Copper Basin (Nevada), where the fossil record of the genus is less clear. We generated models for all NLRs in Genetic Algorithm for Rule Set Production using georeferenced data from the Global Biodiversity Information Facility and Bioclim environmental parameters. For each fossil flora, the best models of individual NLRs were summarized into composite community models, which were taken to represent climatically analogous modern communities and used to infer the paleoclimates of the fossil localities. Our results are generally consistent with previous studies that used other methods to estimate paleoclimates and suggest that McAbee, Princeton, Republic, and Spitsbergen had temperate environments. For the Copper Basin flora, our results show ranges of environmental variables that may be too broad for predicting whether Aesculus was present. Our study appears to be the first to combine the NLR approach and ENM to infer paleoclimates.

The role of land bridges, ancient environments, and migrations in the assembly of the North American flora

“…w = widespread. For consistency and ease of comparison the numbered references and explanatory notes for the BLB and the NALB here are the same as those used for all the land bridges as treated in Graham (2010, appendix 2): Beringia ‐ 1 Budantsev, ; 2 Penhallow, ; 3 LaMotte, ; 5 Heer, ; 6 Chaney, ; 7 Lesquereux, ; 11 Heer, ; 14 Manchester et al, ; 16 Golovneva, ; 17 Stockey et al, ; 21 Budantsev, ; 22 Lavrenko & Fot'janova, ; 24 Vakhrameev, ; 25 Zhilin, ; 26 Velichko et al, ; 27 Arkhipov et al, ; 28 Fradkina et al, , ; 29 Akhmetiev, ; 30 Pavlyutkin & Chekryzhov, ; 35 Wolfe et al, ; 36 Stockey et al, ; 37 Wolfe, 1977; 38 Vakhrameev, ; 39 Pigg et al, ; 40 Harris et al, ; 41 Piel, ; 42 Wolfe & Tanai, ; 43 Becker, ; 44 Leopold & Liu, ; 45 Wolfe & Tanai, ; 46 Reinink‐Smith & Leopold, ; 47 Chelebaeva, ; 48 Pound et al, ; 51 Moiseeva et al, ; 52 Takhtajan et al, et seq. ; 53 McIver & Basinger, ; 54 Bell, .…”

Seasonal Cyclicity in Trace Elements and Stable Isotopes of Modern Horse Enamel

“…The nearest living relative principle justifies the use of modern horse as an analogue for its ancestors and allows the extrapolation of proxy relationships established on modern horses for the interpretation of fossil equid tooth records (e.g. [37] [38] [39]). This makes horses an interesting modern analogue taxon potentially enabling terrestrial paleo-climate reconstruction from the Early Eocene up to modern times ([13] [37] [38] [40] [41]).…”

cRacle: R Tools for Estimating Climate from Vegetation

“…The primary application of CRACLE and related methods is in the reconstruction of paleoclimate from fossil floras. All current applications of CRACLE make assumptions about climatic niche stability through time because the rely on the Nearest Living Relative (NLR) approach to infer elements of fossil taxon niche dimensions by observing the niche space occupied by a closely related extant relative (Mosbrugger and Utescher, 1997; Utescher, 2014; Harris et al 2014). The NLR assumptions will be most valid when the fossil taxa can be placed as members of extant species and least accurate when fossils are members of extinct lineages.…”

“…The NLR assumptions will be most valid when the fossil taxa can be placed as members of extant species and least accurate when fossils are members of extinct lineages. For this reason, NLR and CRACLE will produce the most reliable reconstructions of relatively recent (e.g., Pleistocene and Pliocene) paleoclimate, but may produce reasonable results for much older fossil assemblages where the plant fossil taxa can be placed reliably in extant groups with well sampled modern distributions (e.g., Harris et al 2014).…”