Root-Gutteridge, H., Ratcliffe, V.F., Korzeniowska, A.T., Reby, D., 2019. Dogs perceive and spontaneously normalize formant-related speaker and vowel differences in human speech sounds. Biology Letters 15, 20190555.

https://doi.org/10.1098/rsbl.2019.0555 Domesticated animals have been shown to recognize basic phonemic information from human speech sounds and to recognize familiar speakers from their voices. However, whether animals can spontaneously identify words across unfamiliar speakers (speaker normalization) or spontaneously discriminate between unfamiliar speakers across words remains to be investigated. Here, we assessed these abilities in domestic dogs using the habituation - dishabituation paradigm. We found that while dogs habituated to the presentation of a series of different short words from the same unfamiliar speaker, they significantly dishabituated to the presentation of a novel word from a new speaker of the same gender. This suggests that dogs spontaneously categorized the initial speaker across different words. Conversely, dogs who habituated to the same short word produced by different speakers of the same gender significantly dishabituated to a novel word, suggesting that they had spontaneously categorized the word across different speakers. Our results indicate that the ability to spontaneously recognize both the same phonemes across different speakers, and cues to identity across speech utterances from unfamiliar speakers, is present in domestic dogs and thus not a uniquely human trait.

Ruebsam, Ruebsam, W., Reolid, M., Schwark, L., 2020. δ C of terrestrial vegetation records Toarcian CO and climate 2 gradients. Scientific Reports 10, 117.

https://doi.org/10.1038/s41598-019-56710-6 Throughout Earth's history, variations in atmospheric CO concentration modulated climate. Understanding 2 changes in atmospheric carbon cycle is therefore pivotal in predicting consequences of recent global warming. 13 Here, we report stable carbon isotopes (δ C) of molecular land plant fossils complemented by bulk organic and inorganic carbon fractions for early Toarcian (Early Jurassic) sediments that coincided with global warming and 13 a carbon cycle perturbation. The carbon cycle perturbation is expressed by a negative excursion in the δ C records established for the different substrates. Based on differences in the magnitude of the carbon isotope excursion recorded in land plants and marine substrates we infer that the early Toarcian warming was paralleled by an increase in atmospheric CO levels from ~500 ppmv to ~1000 ppmv. Our data suggest that rising 2 12 atmospheric CO levels resulted from the injection of C-enriched methane and its subsequent oxidation to 2 CO . Based on the cyclic nature of the CIE we concluded that methane was released from climate sensitive 2 reservoirs, in particular permafrost areas. Moderate volcanic CO emissions led to a destabilization of the labile 2 permafrost carbon pool triggering the onset of Toarcian climate change only. The main carbon cycle perturbation then subsequently was driven by a self-sustained demise of a carbon-rich cryosphere progressing from mid to high latitudes as reflected by latitudinal climate gradients recorded in land plant carbon isotopes.

Rugenstein, J.K.C., 2020. What goes down must come up. Nature Geoscience 13, 5-7.

https://doi.org/10.1038/s41561-019-0514-4 Differential cycling of carbonate and organic carbon in the mantle may link the Great Oxidation Event and the subsequent increase in carbon isotope values, according to a model that links the Earth's surface and interior. Approximately 2.5 billion years ago, the concentration of oxygen in the atmosphere rose rapidly. The sediment 1 layers that were deposited after this Great Oxidation Event show a pronounced change to highly positive carbon isotope values for hundreds of millions of years during a period that has been termed the Lomagundi 2 event . The coincidence of these two events, which were followed by a comparatively quiescent period in 3 Nature Geoscience Earth's history, has long intrigued geoscientists. Writing in , Eguchi et al. provide an elegantly simple model that mechanistically links both events to differential cycling of carbon in the mantle. They suggest that it is necessary to account for mantle storage, transport and the release of different forms of carbon to accurately interpret Earth's carbon isotope record.