The graph gives the world population between 1950 and 2050. the numbers from today through 2050 are estimates. assume that the projections on the dotted (upper) line are true. what might be one result of the population change?

A really dramatic drop in world population like the dashed line can only be caused by something like war that is not localized (a worse war than WWII.) or a plague or famine. It would have to be something really grotesque.

I always like to tell people about the fruit flies my classes used for genetics. We ordered in about 100 fruit flies. They were kept in a huge pickle jar at the back of the lab. At first they were healthy because they were well fed and we did nothing to hurt them. But then something did happen. I don't know what it was. There were about 1000 fruit flies -- 10 times the original population. We all speculated on what the problem could have been, but no one knew for sure.

At first the only symptom was inactivity. They had plenty of things to eat and some variety. Still many of them did not fly. then they started dying. More and more of them died until there were only a few left. We did our best to keep them alive, but they went too.

What happened?  It wasn't food. It wasn't war. It wasn't space problems. In the end we guessed it was contamination. They died of disease caused by contamination. They couldn't get rid of the waste, and neither could we. Sound familiar? It should.

The red line has no explanation that we can surmise other than the cities will become too crowded and the rural areas won't be able to grow what is needed for their survival.