I have a solution for the twice size spider monkey finds. The Lachamps geomagnetic excursion of 40kya was caused by a dark matter comet impact on the south coast of Australia, creating the Nullarbor plain. The energy of the dark matter impact was enough to disrupt the mantle flow and therefore the Earth's magnetic field. This collapse of the geomagnetic field, evidenced by a spike in beryllium-10 in ice core data, would have let cosmic radiation erode the ozone layer. This would then have led to Earth's surface being awash with intense solar radiation.
The comet impact also had the energy to lift the entire lithosphere, creating a landbridge stretching from S.E. Asia, arcing across the Pacific and reaching Mexico. This allowed species to cross from one continent to another and would explain the 40,000 year old human footprints discovered by Professor Gonzalez.Attachment #1: Lachamps_DM_Comet_Impact_40kya.jpg