Lakes not Oceans

http://news.yahoo.com/s/livescience/20090727/sc_livescience/oldestanimalfossilsfoundinlakesnotoceans

After reading the article about the earliest animals on earth coming from lakes not oceans I began to think about this:

The humanoid bent over his campfire next to the lake and watched the moon rise. Though there were already plants and trees he wondered why animals and other species hadn't evolved yet. His timespace saucer stood next to the nearest tree. Before he got back in after a restful nights sleep next to the lake he had been happy that there was absolutely no wildlife to worry about.

Before he left he deposited excrement next to the lake. He wondered if this was a mistake because other humanoids sometimes brought life to a planet in this way by accident. "So be it!", he thought. If taking a crap next to this beautiful lake brought life to this planet so much the better. His superiors would never know, after all, because he wasn't filming this activity. He climbed aboard his time space saucer and soon instantly was at another timespace and back home on his home planet light years away.