2018.(1) This year, Susana Kimura joined me to cover the section on Pharmaceuticals and Hormones. We welcome any comments you have on this Review. Numerous abstracts were consulted before choosing the best representative ones to present here. Abstract searches were carried out using Web of Science, and in many cases, full articles were obtained. A table of acronyms is provided (Table 1) as a quick reference to the acronyms of analytical techniques and other terms discussed in this Review. Table 2 provides some useful Web sites.

Rizal, Y., Westaway, K.E., Zaim, Y., van den Bergh, G.D., Bettis, E.A., Morwood, M.J., Huffman, O.F., Grün, R., Joannes-Boyau, R., Bailey, R.M., Sidarto, Westaway, M.C., Kurniawan, I., Moore, M.W., Storey, M., Aziz, F., Suminto, Zhao, J.-x., Aswan, Sipola, M.E., Larick, R., Zonneveld, J.-P., Scott, R., Putt, S., Ciochon, R.L., 2020. Homo erectus Last appearance of at Ngandong, Java, 117,000 - 108,000 years ago. Nature 577, 381-385.

https://doi.org/10.1038/s41586-019-1863-2 Homo erectus erectus is the founding early hominin species of Island Southeast Asia, and reached Java (Indonesia) H. erectus more than 1.5 million years ago. Twelve calvaria (skull caps) and two tibiae (lower leg bones) were discovered from a bone bed located about 20 mabove the Solo River at Ngandong (Central Java) between 1931 H. erectus and 1933, and are of the youngest, most-advanced form of . Despite the importance of the Ngandong fossils, the relationship between the fossils, terrace fill and ages have been heavily debated. Here, to resolve the age of the Ngandong evidence, we use Bayesian modelling of 52 radiometric age estimates to establish - to our knowledge - the first robust chronology at regional, valley and local scales. We used uranium-series dating of 40 39 40 39 speleothems to constrain regional landscape evolution; luminescence, argon/ argon ( Ar/ Ar) and uranium- series dating to constrain the sequence of terrace evolution; and applied uranium-series and uranium series - electron-spin resonance (US - ESR) dating to non-human fossils to directly date our re-excavation of Ngandong. We show that at least by 500 thousand years ago (ka) the Solo River was diverted into the Kendeng Hills, and that it formed the Solo terrace sequence between 316 and 31 ka and the Ngandong terrace between about 140 and 92 ka. Non-human fossils recovered during the re-excavation of Ngandong date to between 109 and 106 ka (uranium-series minimum) and 134 and 118 ka (US - ESR), with modelled ages of 117 to 108 thousand years H. erectus (kyr) for the bone bed, which accumulated during flood conditions. These results negate the extreme ages that have been proposed for the site and solidify Ngandong as the last known occurrence of this long-lived species.

Robinson, K.J., Fecteau, K.M., Gould, I.R., Hartnett, H.E., Williams, L.B., Shock, E.L., 2020. Metastable equilibrium of substitution reactions among oxygen- and nitrogen-bearing organic compounds at hydrothermal conditions. Geochimica et Cosmochimica Acta 272, 93-104.

http://www.sciencedirect.com/science/article/pii/S0016703719307872 Measured abundances of organic compounds can reveal information about the environments in which they formed. Since organic compounds can be mobilized and released from geologic and planetary settings, they have the potential to provide insights into environments that are difficult to observe directly. To advance our understanding of these environments, this study identifies organic reactions that approach metastable equilibrium in experiments, so that future studies can predict geochemical conditions in remote settings (e.g., deep Earth, extraterrestrial bodies) by monitoring reaction ratios of compounds involved in similar organic reactions. At high temperatures organic redox reactions can equilibrate, which allows comparisons with thermodynamic properties to yield estimates of reaction conditions. However, redox reactions may equilibrate too slowly to be applicable to lower temperature systems. To explore metastable equilibria at lower temperatures, we studied substitution reactions that tend to be faster than redox reactions. In this study, we demonstrate that oxygen- and nitrogen-bearing organic compounds at hydrothermal conditions undergo a series of simultaneous substitution reactions that rapidly approach steady-state ratios indicative of metastable equ ilibrium. Four sets of aqueous experiments were performed at 250 °C and 40 bar, each beginning with a single organic reactant: benzyl alcohol, benzylamine, dibenzylamine, or tribenzylamine. All reactant solutions were prepared with identical bulk elemental compositions by adjusting the concentrations of the starting organic compounds and adding ammonia as needed. After 2 h at hydrothermal reaction conditions, all of the model