1) what evidence is there that the human species has been successful so far? explain.
2) what environmental pressures in the past do you think were most important in shaping the human species as it exists today?
3) what environmental pressures exist now that you think may be shaping the human species?
4) what environmental pressures do you think may affect humans as earth becomes more populated with humans in the future? explain how these pressures may affect human traits.

1) What evidence is there that the human species has been successful so far? Explain. 

Successful evolutionarily means "surviving and spreading geographically". Since we are far from extinction and we've spread all over the world, we are successful as a species. 

I believe that the environmental pressures that exist now and that may be shaping the human species are the use of land, the extraction of resources, greenhouse emissions and water use. This are being used by use more and more as we start overpopulating the earth.

"do a testcross with a homozygous recessive plant."

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.