which evidence recorded at seismic stations following an earthquake supports the inference that Earth's interior changes from Solid Rock to Molten iron and nickel at the mantle-core boundary.

Many archeologists and anthropologists disagree with dr. thorne's view.  thorne strongly believes that what many calls "homo erectus"  was in fact  homo sapiens,  and that they migrated out of africa almost 2 million years ago and dispersed throughout europe and asia. that's way different  from what scientists have always believed about the evolution of the species.