Explain two ways in which scientists use fossils to determine environmental change

Hello.  Happy to help.

1)  Coast Lines:  The location of marine fossils can help determine where and when ancient coast lines were in the past.2)  Climates:  Fossils can be used to determine the past climates.  (Was an area cooler or wetter than the present.)

The presence of marine or land fossils indicates whether the land at one time was at the bottom of the ocean or not.

Also, you could mention radioactive dating and relative dating.  I am sure that is mentioned in your curriculum. 

Hope that helps.

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.