In this study we evaluated migration models to the Americas by using the information contained in native mitochondrial genomes (mitogenomes) from North America. Molecular and phylogeographic analyses of B2a mitogenomes, which are absent in Eskimo-Aleut and northern Na-Dene speakers, revealed that this haplogroup arose in North America ∼11-13 ka from one of the founder Paleo-Indian B2 mitogenome...

The oxygen isotopic composition of hydrothermally altered rocks partly originates from the interacting fluid. We use the triple oxygen isotope composition ((17)O/(16)O, (18)O/(16)O) of Proterozoic rocks to reconstruct the (18)O/(16)O ratio of ancient meteoric waters. Some of these waters have originated from snowball Earth glaciers and thus give insight into the climate and hydrology of these c...

A critical challenge in paleoclimate data analysis is the fact that the proxy data are heterogeneously distributed in space, which affects statistical methods that rely on spatial embedding of data. In the paleoclimate network approach nodes represent paleoclimate proxy time series, and links in the network are given by statistically significant similarities between them. Their location in spac...

Deciphering the sources of eolian dust on the Chinese Loess Plateau (CLP) is fundamental to reconstruct paleo-wind patterns and paleo-environmental changes. Existing datasets show contradictory source evolutions of eolian dust on the CLP, both on orbital and tectonic timescales. Here, the silicate Sr and Nd isotopic compositions of a restricted grain size fraction (28-45 μm) were measured to tr...

The stable boron isotope ratio (B/B) in marine carbonates is used as a paleo-pH recorder and is one of the most promising paleo-carbonate chemistry proxies. Understanding the thermodynamic basis of the proxy is of fundamental importance, including knowledge on the equilibrium fractionation factor between dissolved boric acid, B(OH)3, and borate ion, B(OH)4 – ( B OH 3 B OH 4 , hereafter (B3–B4))...

Paleoclimate, changes of climate over Earth's history, provide valuable insights about the effects of human perturbations to climate, even though there is no close paleoclimate analog of the strong, rapid forcing that humans are applying to the climate system. International discussions of human-made climate change (e.g., IPCC) rely heavily on global climate models, with less emphasis on inferen...

The cosmogenic radionuclide 10Be is produced by cosmic-ray spallation in Earth’s atmosphere. Its production rate is regulated by the geomagnetic field intensity, so that its accumulation rate in aeolian sediments can, in principle, be used to derive high-resolution records of geomagnetic field changes. However, 10Be atmospheric fallout rate also varies locally depending on rainfall rate. The ac...

This chapter uses dental morphology to make inferences about how the New World was first colonized. The major emphasis is on the initial Macro-Indian migration based on dental traits observed in Paleo-Indian, Archaic, and more recent prehistoric crania. The major results are as follows: (1) Arctic and Subarctic native dentitions differ enough from those of Macro-Indians to indicate separate mig...

Paleo-colour scientists have recently made the transition from describing melanin-based colouration in fossil specimens to inferring life-history traits of the species involved. Two such cases correspond to counter-shaded dinosaurs: dark-coloured due to melanins dorsally, and light-coloured ventrally. We believe that colour reconstruction of fossils based on the shape of preserved microstructur...

Several clues indicate that Titan’s atmosphere has been depleted in methane during some period of its history, possibly as recently as 0.5-1 billion years ago. It could also happen in the future. Under these conditions, the atmosphere becomes only composed of nitrogen with a range of temperature and pressure allowing liquid or solid nitrogen to condense. Here, we explore these exotic climates t...