Evolution (2001) Part I- "They've Evolved into Primates."

Spoiler Level – Low-to-moderate

The Movie – A meteorite containing simple life lands on Earth. The life quickly evolves and becomes a threat to humanity. An unlikely team of incompetent scientists and students must save the day.

When I was younger, I remember thinking this movie was enjoyable enough. As an adult, I still think it's cute in many ways, but I can barely go five minutes without finding something new about the science that bothers me. I'm going to have to divide this into at least a couple parts, and I'm still not going to be able to cover everything this movie gets wrong. 

The Scene –  Once again, I'm going to discuss a problem with the overall premise of the movie rather than a single particular scene. I wish that I could still be surprised by this sort of thing, but the movie Evolution completely butchers the concept of evolution.

When the alien creatures first land on earth, they are single-celled organisms. In a day, the aliens have evolved into flatworms, and within a few weeks, there are intelligent primates. This is slightly faster than we would expect.

Time Lapse: Somewhere between 18 hours and a billion years. From Evolution.

The Science – First, a short and oversimplified explanation of evolution. There are two main ideas to keep in mind: descent with modification and natural selection.

Descent with modification: Reproduction is imperfect. Every child inherits DNA from its parents, but that DNA also accumulates some mutations that neither parent has. The changes to the DNA, mutations, manifest themselves in physical changes in the child. Mutations are essentially random.

Natural selection: The vast majority of mutations will be harmful or make no difference, but a very small fraction will be helpful. What counts as a beneficial mutation will depend on the environment the organism is in. One mutation could lead to an adaptation that's helpful in one set of conditions but harmful in another. An individual with a beneficial change has a higher likelihood of surviving and reproducing. The mutated gene gets passed on and on and and is present in more individuals of each new generation. When a population accumulates enough mutations, it can be eventually be classified as a different species from its ancestors and distant cousins. However, the line for species distinction is often fuzzy.

Because of these properties, evolution is slow. Generation time is a major limiting factor. The creatures in the movie reproduce quickly but just not quickly enough to justify the movie's timeline. Say the aliens give birth to a new generation every minute. (The early single-celled organisms actually divide even faster than that, but later multicellular aliens are clearly not reaching that rate.) That would be less than 50,000 generations in the movie's span of about a month. Even humans and chimpanzees are separated by more generations than that. So this just isn't enough time to generate the diversity of life seen in the movie.

Not my uncle. Maybe my 250,000 x great uncle. From Evolution.

What bothers me the most in Evolution is that the aliens essentially undergo the exact same evolutionary process that happened on Earth. They begin as single-celled organisms, and we later see flatworms, insects, amphibians, reptiles, and primates. This promotes the misconception that evolution is a sort of ladder, progressing towards a specific goal. That's not the case. With a different origin of life, you would see different random mutations and a different set of environmental pressures. So the resulting creatures would not be the same.

Fixing the Scene – Under no circumstances will evolution be fast as it is the movie. Even if the aliens did nothing but reproduce, they couldn't form that many species in a month. (And that would raise further questions about where they get the energy and chemicals for reproduction, which I won't have a chance to go into.) At one point, the movie skips ahead a couple weeks in time. I would recommend making that time jump years. It probably still wouldn't be enough time, but it would help.

The evolutionary ladder issue is easier. Just don't use Earth-like animals for aliens. Several of the creatures shown are quite creative and not obvious analogs to known animals. The movie should stick to that. It's possible to show increasing complexity without mimicking the the progression of evolution seen on earth. Most of all, just ditch the primates. We're not the pinnacle of evolution. 

Next week – We're going to continue with Evolution to tackle a very different issue: the periodic table and why arsenic is lethal.