Evolution (2001)

This was a very comical movie that kept you laughing throughout the fictional plot. The basic premise of the movie is that a meteor crashes in a desert and lands in an underground cavern. After taking samples, they determine that its an extraterrestrial being that evolves very fast. This is pretty much where the science ends. They discover that the aliens evolve extremely fast and develop traits that were not already introduced into the genome. The first organisms they discover resemble flat worms and reproduce exponentially through mitosis. These organisms reproduce very fast, much faster than possible in real life. They are viewing one worm under a microscope and then another guy goes to view the worm and it already split into around 4 worms. This is a highly unlikely speed of reproduction. After returning to the cave only the next day, they find that the flat worms are also surrounded by fungi. One of the constraints on natural selection proposed by Darwin states that the trait that will be changed must already be in the organism. Or simply, a human could never produce claws like Wolverine, or shoot lasers from your eyes like Cyclops from the X-men comic. therefore, these round worms could not evolve so quickly into a different type organism. Soon, after returning to the cave, they find it teeming with life that resembles a rainforest. They discover that all the aleins are unable to breathe oxygen and is lethal to them. Soon, there are dinosaur-like creatures that are able to fly, but as one enters the oxygen, she dies, but as she dies she spits out an egg that hatches into another  alien dinosaur that is able to breathe oxygen. This almost supports a Lamarack idea that a trait influenced by the environment can be passed on to the next generation. This process would be much slower, but due to the increased evolutionary characteristics these aliens have, it makes sense that this would happen so fast. Eventually, the army steps in and ignites all the aliens with napalm. They then all combine to form a super large creature that resembles a giant flat worm. This creature is so large and would not be able to function metabolically. It would be unable to take in the amount of food necessary for all the metabolic reactions necessary for survival. They determine that the worm is most likely poisonous to selenium which is found in Head and Shoulders shampoo. They then in a funny way kill the alien with Head and Shoulders and save the day. In conclusion, the movie was entertaining, but did not show much scientific thought. The evolutions depicted in the movie were unlikely, and the mutations occurred extremely fast, almost never skipping a generation.