MEXICO: The debate about what caused the extinction of charismatic megafauna in both Europe and North America is heating up. It is no secret that the cause of the extinction of megafauna such as the woolly mammoth, Irish elk, and the European elephant has been a longstanding debate among scientists who either typically blame human “overkill” or climate change for their demise. But a recent paper in Science by University of Adelaide scientist Alan Cooper and coauthors uses ancient DNA, radiocarbon dating, and detailed statistics to show that humans may have just been the final nail in the extinction coffin for many of these animals as their extinctions are more closely tied to climate cycles than the arrival of humans.
This new study addresses some of the previous major difficulties in addressing the “overkill versus climate” debate by using fossils that are accurately aged with radiocarbon dating, and also taking into account ancient DNA (aDNA). Paleontologists are typically only able to use morphology of fossil bones to tell species apart—but when the fossils in question are only thousands of years old, small fragments of aDNA can be obtained and scientists can determine if two similar looking fossils are actually from the same species. And it turns out, sometimes they are not. What has previously been recognized as a continuous record of certain species was shown to actually be a series of closely related similar looking bones from different species based on DNA evidence.
Pakistan to get $3b loan from Islamic Trade Financing Corporation
ISLAMABAD: Islamic Trade Financing Corporation (ITFC) to provide Pakistan with a $3 billion loan, according to an official statement released...
