Fossils represent invaluable data to reconstruct the past history of life, yet fossil-rich sites are often rare and difficult to find. The traditional fossil-hunting approach focuses on small areas and has not yet taken advantage of modelling techniques commonly used in ecology to account for an organism's past distributions. We propose a new method to assist finding fossils at continental scal...

Molecular sequence data provide information about relative times only, and fossil-based age constraints are the ultimate source of information about absolute times in molecular clock dating analyses. Thus, fossil calibrations are critical to molecular clock dating, but competing methods are difficult to evaluate empirically because the true evolutionary time scale is never known. Here, we combi...

The fossil record is well known to be incomplete. Read literally, it provides a distorted view of the history of species divergence and extinction, because different species have different propensities to fossilize, the amount of rock fluctuates over geological timescales, as does the nature of the environments that it preserves. Even so, patterns in the fossil evidence allow us to assess the i...

nowadays the position of the renewable energy is so important because of the environment pollution and the limitation of fossil fuels in the world. energy can be generated more and more by the renewable sources, but the fossil fuels are non-renewable. one of the most important renewable sources is the wind energy. the wind energy is an appropriate alternative source of fossil fuel. the replacem...

BACKGROUND Molecular dating has gained ever-increasing interest since the molecular clock hypothesis was proposed in the 1960s. Molecular dating provides detailed temporal frameworks for divergence events in phylogenetic trees, allowing diverse evolutionary questions to be addressed. The key aspect of the molecular clock hypothesis, namely that differences in DNA or protein sequence between two...

single roofed, indicating that the specimen was an immature. The skull and wing are now in the collection at Humboldt State College. This record is additional support for the assumption made by Cogswell (Condor, 54, 1952:117) that the northward movements of wandering vagrants of this species in the fall may be fairly commonplace, at least along the Pacific coast.--Row E. MALL, Humboldt State Co...