https://doi.org/10.1093/aob/mcz153 Background and Aims:Many monotypic gymnosperm lineages in south-east China paradoxically remain in relict status despite long evolutionary histories and ample opportunities for allopatric speciation, but this paradox has received little attention and has yet to be resolved. Here, we address this issue by investigating the Pseudotaxus chienii evolutionary history of a relict conifer, (Taxaceae). Methods:DNA sequences from two chloroplast regions and 14 nuclear loci were obtained for 134 samples. The demographic history was inferred and the contribution of isolation by environment (IBE) in patterning genetic divergence was compared with that of isolation by distance (IBD). Key ResultsThree genetic clusters were identified. Approximate Bayesian computation analyses showed that the three clusters diverged in the late Pliocene (~3.68 Ma) and two admixture events were detected. Asymmetric gene flow and similar population divergence times (~ 3.74 Ma) were characterized using the isolation with migration model. Neither IBD nor IBE contributed significantly to genetic divergence, and the contribution of IBE was much smaller than that of IBD. P. chienii Conclusions:These results suggest that several monotypic relict gymnosperm lineages like in south- in situ east China did not remain and undiversified for millions of years. On the contrary, they have been evolving and the extant populations have become established more recently, having insufficient time to speciate. Our findings provide a new perspective for understanding the formation and evolution of the relict gymnosperm flora of China as well as of the Sino-Japanese Flora.

Krause, J.W., Lomas, M.W., 2020. Understanding diatoms' past and future biogeochemical role in high -latitude seas. Geophysical Research Letters 47, e2019GL085602.

https://doi.org/10.1029/2019GL085602 Abstract: Because cold-water diatoms' baseline elemental density (BED) is substantially higher than temperate diatoms, previous polar studies may have underestimated diatoms' contribution to elemental standing stocks, contribution to particulate organic carbon (POC) export and incorrectly modeled their susceptibility to future warming. We apply cold-water diatom allometry to Arctic field samples and derive diatom growth rates ranging - 1 from 0.01 - 0.68 day , versus unrealistically high rates estimated using temperate diatom allometry. Reanalysis of published Southern Ocean data (Antarctic Environment and Southern Ocean Process Study and European Iron Fertilization Experiment) shows that diatom POC was significantly underestimated and diatoms could have accounted for a majority of POC export. However, during some field programs (Kerguelen Plateau), temperate allometry properly accounted for diatom biomass. We also predict that warming sea surface temperature may alter high-latitude diatom BED, suggesting that eve n if abundances do not change with warming, the reduced diatom BED will likely lower the trophic-transfer efficiency and their total carbon flow to consumers. Plain Language Summary: High-latitude marine regions are warming faster than other marine systems. We show that the role of diatoms in these systems, already thought to be important, was systematically underestimated in some studies due to insufficient und erstanding of cold-water diatoms' physiology, specifically their high elemental density. When applying cold-water-diatom elemental density relationships to original and previously published high-latitude field data, diatom growth rates were rapid (up to a doubling per day), and they could account for most of the organic carbon standing stock and its export - original publications inferred contributions <20%. We predict that cold-water diatom elemental density will decline with increasing warming. Such a decline in diatom food quality (less element per volume), even without diatom abundance declines, may reduce transfer of their material to consumers and affect food webs.

Kreling, N.E., Zaparoli, M., Margarites, A.C., Friedrich, M.T., Thomé, A., Colla, L.M., 2020. Extracellular biosurfactants from yeast and soil - biodiesel interactions during bioremediation. International Journal of Environmental Science and Technology 17, 395-408.

https://doi.org/10.1007/s13762-019-02462-9