Available data point to a 4‐km‐high Tibetan Plateau by 40 Ma, but 100 molecular‐clock papers have linked supposed recent uplift to young node ages

Abstract

The aims of this study were to synthesize data on the orogeny of the Tibetan Plateau (TP), with a focus on its elevation since the collision of the Eurasian and Indian plates, and to review the arguments in 100 phylogeny-cum-biogeography papers that have linked young inferred divergence times to recent TP uplift phases. I surveyed the literature on the geological history of the TP, focusing on different types of data used to infer its past height. I also tabulated the supposed TP history (and supporting references) in papers since 1998. Since the early 1990s, evidence from tectonics, isotopes, fossils and climate simulations increasingly indicates that the TP has been 4-5 km high since the mid-Eocene. The data also indicate that the Indian summer monsoon, South-east Asian summer monsoon, and Central Asian winter monsoon arose at different times and are unrelated to Tibetan uplift. A growing number of studies by biologists, however, are linking node ages between 0.5 and 15 Ma to specific (author-dependent) uplift phases of the TP citing geological papers that are outdated or miscited. Biogeography of the TP thus currently appears to be in a self-created bubble that encloses hundreds of authors and referees. Our understanding of the biogeography of Tibet requires up-to-date interpretation of its geological history and more fieldwork on local ecological habitat diversity, the plateau's history during the Pleistocene and the distribution of possible refugia.

Uplift-driven diversification in the Hengduan Mountains, a temperate biodiversity hotspot

“…We expected regional differences to reflect contrasting times of orogeny, in particular the prediction of the uplift-driven diversification hypothesis that in situ speciation increases with mountain-building activity. In this context, the late Miocene emerges as an important reference point, because previous studies of geology and paleontology indicate that the Hengduan Mountains achieved their current height only after this time, whereas the Himalayas and central QTP did so before (4,13,15,17,21). Here, our phylogenetic inferences, which make no prior assumptions about the timing of geological events, show that after about 8 Ma the rate of in situ diversification increased in the Hengduan Mountains (Fig.…”

“…13, p. 7). Here, our focus on distinguishing the younger and more speciesrich Hengduan Mountains region from the Himalayas-QTP is in the spirit of that advice, and our results suggest that at least some of the referenced cases of diversification could be more accurately interpreted as coincident with orogeny of the Hengduan region, not the older QTP.…”

“…In a recent review, Renner (13) argued that numerous phylogenetic studies have misinterpreted the Earth sciences literature and incorrectly attributed relatively young (Miocene and later) estimates of lineage divergence to QTP uplift, and recommended that "Biogeographical discussions should also keep in mind expected differences in the biota of the TP and those in the Himalayas, the Kunlun range to the N, the Pamir and Karakoram to the W, and Hengduan Mountains to the E" (ref. 13, p. 7).…”

“…Here, our focus on distinguishing the younger and more speciesrich Hengduan Mountains region from the Himalayas-QTP is in the spirit of that advice, and our results suggest that at least some of the referenced cases of diversification could be more accurately interpreted as coincident with orogeny of the Hengduan region, not the older QTP. Indeed, several of the studies cited in Renner (13) are the original sources of molecular data for the clades analyzed here and include many Hengduan species. It thus seems important to emphasize that, despite precedent in the literature for considering the Hengduan Mountains to be simply part of a greater biogeographic region that includes the Himalayas and QTP (e.g., refs.…”

“…However, some points of consensus have emerged from recent syntheses (4,(11)(12)(13). One is that the central plateau was uplifted first, forming a "proto-QTP" as early as 40 Mya, with subsequent outward extensions by the early Miocene (11,14).…”