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Smycka, J.

Publications and source records attributed to Smycka, J..

2 recordsLinked to original sources

Tip rate estimates can predict future diversification, but are unreliable and context dependent

Understanding the variability of processes leading to the emergence of new lineages is one of the major tasks of macroevolution as a scientific field. Recent years have seen the rise of rate-variable diversification models and metrics that estimate the rates of species diversification at the tips of phylogenetic trees and are thus potentially useful for predicting future evolutionary success of individual species. These methods use various assumptions about the variability and heritability of diversification rates. However, the general performance of rate-variable diversification methods have never been consistently tested against real world data. Here we explore the capacity of multiple rate-variable diversification methods to predict near-future diversification using temporal slices of empirical fossil and extant phylogenies. We do this using a newly developed approach similar to generalized linear models, allowing us to quantify the relationship between predictor tip rates and subsequent diversification rates derived from a probability distribution of numbers of daughter species. We find that tip rates estimated from current methods have non-zero but limited capacity to predict diversification in both fossil and extant phylogenies. The quality of the predictions depends not only on the methods used but also on the specific phylogeny, suggesting that diversification dynamics in some taxa may be more predictable in principle. Our results suggest that future cladogenesis can be, to a certain extent, predicted using existing tip rate methods, but the quality of such predictions is highly variable and depends on factors that are difficult to evaluate in practical applications.

evolutionary biology↗

Discovery of cryptic plant diversity in one of the harshest environments: the rooftops of the Alps

High altitude temperate mountains have long been considered devoid of life owing to high extinction or low speciation rates during the Pleistocene. We performed a phylogenetic and population genomic investigation of an emblematic high-altitude plant clade (Androsace sect. Aretia, 31 currently recognized species), based on plant surveys conducted during alpinism expeditions. Surprisingly, we inferred that this clade originated in the Miocene and continued diversifying through Pleistocene glaciations, and discovered three novel species of Androsace dwelling on different bedrock types on the rooftops of the Alps. This suggests that temperate high mountains have been cradles of plant diversity even during the Pleistocene, with in-situ speciation driven by the combined action of geography and geology. Our findings have an unexpected historical relevance: H.-B. de Saussure likely observed one of these species during his 1788 expedition to the Mont Blanc and we describe it here, over two hundred years after its first sighting.

evolutionary biology↗