what are two themes that would be appropriate for thematic time lines of important events from prehistory to A.D.1600.

Answer 1

I can't think of one or two themes that span that entire HUGE amount of time. You're talking thousands and thousands of years. One major change, in pre-history, is the development of agriculture. Another major theme would be the Roman Empire, which had a huge impact on Western civilization over hundreds of years. Another might be the rise and fall of empires (there were many that "spread" ideas and were influential for a time, then faded or were overtaken). But none of these spans all of human existence up to 1600 c.e. Ms. Sue, any ideas?

Answer 2

I thought of the rise and fall of empires all over the world.

Another theme could be scientific discoveries and inventions.

Religions could also work well.

Answer 3

Yes, I thought of inventions, too. From the wheel to the printing press, and others along the way that changed the way people lived in important ways. Religion would also work, but that's VERY complicated, but has had an almost immeasurable impact on civilization.