28. Watch the short video in the "Building a Reference Map" section. Elephant populations differ from one another. These differences are due to geographic distance and the length of time since their ancestors
separated from one another. Explain how this relationship affects their relatedness.

relative dating involves things like higher layers are most recent than rocks lower in the sequence. this can be extended to the known sequence of fossils. rocks containing rabbit fossils are later than those containing dinosaur fossils.  

absolute dating methods mainly use radioactive elements that have known rates of decay and produce recognizable products. for example potassium 40 decays to produce argon. once a rock has solidified the argon is trapped. by measuring the argon and potassium0 you can get an accurate number for the age.  

some other methods are good for archaeological ages. dendrochronology involves recognizing the sequence of tree rings. the orientation of magnetized particles in baked clay can be used to date a fire.

hope this .. .

the endomembrane system i think

ask your friends for what they got then copy it down if you don't have any friends which is fine than google it or pay the teacher