15. relate what natural selection process mighthave led to a smaller jaw with fewer teeth inhumans?

Natural selection is the process where the individuals with better traits survive ( in where they are ) while the individuals with less suited traits for that environment dies.

In your case, wouldn't the answer be  something among the lines of "The humans with bigger jaws and more teeth found it difficult to eat or find enough food to satisfy their stomachs"? ( It makes sense. Usually, if the animal has bigger features, like mouth, and more teeth, they would need more food or nutrient to grow those bigger features. If one has bigger/more features, then that typically means they are bigger as well, which also means they need a bit more food. ^^ Yes, my logic is a bit weird, but it helps out. )

Your asshahs has a nice

Proteins are the workhorses of the cell, controlling virtually every reaction within as well as providing structure and serving as signals to other cells. proteins are long chains of  amino acids  , and the exact sequence of the amino acids determines the final structure and function of the protein. instructions for that sequence are encoded in  genes  . to make a particular protein, a messenger ribonucleic acid (mrna) copy is made from the gene (in the process called  transcription  ), and the mrna is transported to the  ribosome  . protein synthesis, also called  translation  , begins when the two ribosomal subunits link onto the mrna. this step, called initiation, is followed by elongation, in which successive amino acids are added to the growing chain, brought in by transfer rnas (trnas). in this step, the ribosome reads the  nucleotides  of mrna three by three, in units called  codons  , and matches each to three nucleotides on the trna, called the anticodon. finally, during termination, the ribosome unbinds from the mrna, and the  amino acid  chain goes on to be processed and folded to make the final, functional protein