9. The African Sahara changes less when a disease hits than when that same disease hits the American Prairies. How can you explain this observation?

C) to ensure each new cell has an exact copy of the dna

The basic building blocks of dna and rna are nucleotides

Compound light microscope

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.