Evidence for close-range hunting by last interglacial Neanderthals.

Animal resources have been part of hominin diets since around 2.5 million years ago, with sharp-edged stone tools facilitating access to carcasses. How exactly hominins acquired animal prey and how hunting strategies varied through time and space is far from clear. The oldest possible hunting weapons known from the archaeological record are 300,000 to 400,000-year-old sharpened wooden staves. These may have been used as throwing and/or close-range thrusting spears, but actual data on how such objects were used are lacking, as unambiguous lesions caused by such weapon-like objects are unknown for most of human prehistory. Here, we report perforations observed on two fallow deer skeletons from Neumark-Nord, Germany, retrieved during excavations of 120,000-year-old lake shore deposits with abundant traces of Neanderthal presence. Detailed studies of the perforations, including micro-computed tomography imaging and ballistic experiments, demonstrate that they resulted from the close-range use of thrusting spears. Such confrontational ways of hunting require close cooperation between participants, and over time may have shaped important aspects of hominin biology and behaviour.

40 GHz electro-optic modulation in hybrid silicon-organic slotted photonic crystal waveguides.

In this Letter we demonstrate broadband electro-optic modulation with frequencies of up to 40 GHz in slotted photonic crystal waveguides based on silicon-on-insulator substrates covered and infiltrated with a nonlinear optical polymer. Two-dimensional photonic crystal waveguides in silicon enable integrated optical devices with an extremely small geometric footprint on the scale of micrometers. The slotted waveguide design optimizes the overlap of the optical and electric fields in the second-order nonlinear optical medium and, hence, the interaction of the optical and electric waves.