O’Brien et al. Genome Biology (2016) 17:90 DOI 10.1186/s13059-016-0942-z CORRESPONDENCE Open Access Response to Comment by Faurby, Werdelin and Svenning Stephen J. O’Brien1,2*, Klaus Peter Koepfli1,3, Eduardo Eizirik4, Warren Johnson3, Carlos Driscoll5, Agostinho Antunes6, Anne Schmidt-Kuntzel7,8, Laurie Marker8 and Pavel Dobrynin1 Please see related Correspondence article: http://genomebiology.biomedcentral.com/articles/10.1186/s13059-016-0943-y and related Research article: http://genomebiology.biomedcentral.com/articles/10.1186/s13059-015-0837-4 Faurby, Werdelin, and Svenning raise some interesting during the late Pleistocene by multiple molecular and valid points around the interpretation of the genomics methods, coincident with abrupt mammal extinction and fossil data on the history of the African cheetah, a events in North America and Eurasia at that time. The species that has fascinated humankind for millennia. They genome-wide Dadi result suggested an earlier more emphasize a controversy to which we alluded in our art- ancient demographic contraction ~100,000 years ago. icle [1] and they offer an alternative explanation to the Something caused the massive diversity loss in their scenario we had suggested for the time and place of history. We suggested two scenarios: the earliest—a demographic events that preceded modern African migration of North American cheetahs out of North cheetah populations. We fully agree that there are import- America >100,000 years BP, and a second—when ant areas of uncertainty in this conundrum and welcome cheetahs went extinct from North America the opportunity to reconsider and to offer our view into 10,000–12,000 years ago. It may be relevant that the natural history of Acinonyx jubatus. We do believe North American pumas show a near identical that the integration of fossil and molecular data seems a quantity of genomic depletion as African cheetahs, good way to get toward the truth, so we shall try to suggesting they were also extirpated form North emphasize two considerations in our comments: first, the America during the quaternary mammal extinction most parsimonious interpretation of data; and second, the and repopulated from South America subsequently robustness of available and relevant fossil and molecular [3–5]. Was this an irrelevant coincidence or was a data. single North American or global event responsible? Some aspects to consider: Theanswerisuncertain. 2. Please refer to [6, 7] which detail the latest relatively 1. The extreme genetic depletion of modern cheetahs robust molecular phylogenies for the Felidae and a seems true and validated by Dobrynin et al., as has derivative study [8] that postulates parsimonious been suggested with multiple metrics across several historic migration scenarios based upon phylogeny, decades [1–3]. Two possible historic events that the fossil record, present and past geographical could account for the genetic reduction are extended occurrence, and geological sea levels. That phylogenetic continental migration events and/or population study reported in [6] examined 18,853 bp of bottlenecks (a.k.a. founder effect). We offered nuclear sequence (autosome, X and Y possible (but not proven) explanations based upon chromosome), which yielded 3440 parsimony dating the latest founder effect at 10,000–12,000 informative sites, and mtDNA sequence, from all 37 Felidae species calibrated with 16 fossil dates [6]. * Correspondence: [email protected] That molecular phylogeny (combined with 1Theodosius Dobzhansky Center for Genome Bioinformatics, Saint Petersburg paleontological, geological and present range) State University, 41A Sredniy Avenue, St. Petersburg 199004, Russia 2Oceanographic Center, Nova Southeastern University Ft Lauderdale, 8000 N. posited the arrival of the ancestors of three Felidae Ocean Drive, Ft Lauderdale, FL 33004, USA Full list of author information is available at the end of the article © 2016 O’Brien et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. O’Brien et al. Genome Biology (2016) 17:90 Page 2 of 3 lineages (Ocelot preceding Lynx, and then preceding Valkenburgh et al. [9] attribute to homoplasy or Puma lineage) into North America, around 8–8.5 parallelisms. But at least three respected authors million years ago (MYA). All three lineages have groups have disagreed [10–12] and opined that the roots in North America with ocelot ancestors adaptive similarities are evidence for homology of appearing first 8.0 MYA, Lynx ancestors 7.2 MYA, North American and African cheetahs supporting and Puma ancestors 6.7 MYA. Cheetah-like genera the modern cheetah origins in North America. (Acinonyx lineage) appear first ~4.9 MYA. Support Adams’ study titled “The cheetah-native American” for this scenario comes from molecular evolutionary [10], classifies the North American cheetah specimens analyses that were supported by 13 cladistic as Acinonyx (precursors of modern Acinonyx)and synapomorphies (large insertion/deletions) [6]. suggests that pronouncing these important cursorial Sometime thereafter, the Acinonyx lineage ancestors, characters as convergence or parallelism “pushes the derived from the North American puma lineage concept of parallel evolution to an unprecedented precursors, would make their way back to Asia from extreme”. Van Valkenburgh et al. [9] actually place North America. The fossil record puts the oldest the Eurasian Acinonyx and the North American cheetah fossils in Asia 3 million years before present Miracinonyx genera as sister taxa, emphasizing the (MYBP). Fossils of Acinonyx and cheetah-looking difficulty in sorting this controversy cleanly. Further cats were in both in Asia and North America from 3 they state “… The common ancestor (of Acinonyx MYA to the late Pleistocene. So the comment in and Miracinonyx) … could have been either Old or their title “There were never any true cheetahs in New World.” North America” depends on what we mean by “true Mark Springer, a noted expert of interpreting cheetahs.” molecular and paleontological evidence across 3. Faurby, Werdelin, and Svenning argue cogently that vertebrate taxa [13], states that “… morphological North American cheetah fossils are all from the studies of eutherian … relationships have failed to genus Miracinonyx, which is not closely related to separate homology and homoplasy and have modern Acinonyx cheetahs, which occur in Africa consistently been misled by the latter … one of the today and in Eurasia throughout the Pliocene and greatest challenges ahead for mammalian Pleistocene fossil deposits. Thus, the trivial name of systematists is to tease apart homology and North American “cheetah” is misleading (they imply homoplasy in morphological characters.” Springer’s we fell into that trap, although these authors study described explicitly how morphological inference themselves use the trivial name “cheetah” ten times erred in over 50 % of ordinal assignments within the in their note). The data supporting the distinctions mammalian radiations due to this issue [13]. of North American species in Miracinonyx from 4. Faurby, Werdelin, and Svenning refer to Barnet et al. Eurasian Acinonyx are the bases of the controversy. [14] who presented a molecular phylogeny that uses A seminal and elegant report by Van Valkenburgh et ancient DNA to place the North American al. [9] concluded that North American cheetah Miracinonyx as a sister to Puma concolor (and not fossils (there were six specimens, one complete and modern Acinonyx), but they acknowledge the limited five fragmented) were cladistically similar based power of a 1302 bp mtDNA dataset. There are other upon ten synapomorphic morphological features details of the Barnett study that may be relevant. that were distinct from Eurasian Acinonyx fossils. First, the actual nucleotide alignment is not This study proposed the distinction of North presented which limits our ability to evaluate their America (Miracinonyx) and Eurasian (Acinonyx) conclusions or assess the extent of homoplasy. genera in 1990. Faurby, Werdelin, and Svenning Further, when Barnet et al. performed a jack-knife affirm this conclusion by stating “… No fossils of analyses, excluding H. jaguarundi from the Acinonyx are known from North America, despite the phylogenic analysis (H. jaguarundi is a sister taxon extensive fossil record from the continent, while no to Puma concolor [6–8]), statistical support for the fossils of Miracinonyx are known outside North sister relationship of Puma-Miracinonyx actually America.” increased, an indication that molecular homoplasy This declarative statement discounts a longstanding was operative in their results [14]. Their conclusion controversy that Van Valkenburgh et al. [9] that American cheetah Miracinonyx is not within acknowledge. First, there are several important the African-Asian Acinonyx group is tentative at best adaptive morphometric characters that are shared and has not been confirmed convincingly. between North America and Eurasian cheetah 5. Faurby, Werdelin, and