What do aliens look like? Inundated as we are with science fiction movies, where aliens come in all different shapes and sizes, one wonders what form a real extraterrestrial would take. You need only look at the diversity of life on our own planet, from bacteria to humans to oak trees, to get a glimpse of what might be possible. The variety is amazing, even though all known life forms have pretty much the same biochemistry and all are based on DNA. Sci-fi directors might look further for inspiration, to extinct species like trilobites or the giant shark Megalodon. But the real pool of possibilities is surely many times greater.
Of course, we are most interested in how intelligent aliens would look — ones we might meaningfully communicate with. On our own planet, that would include apes, dolphins and whales, birds like crows and parrots, invertebrates like squids and octopuses, and elephants. If we throw in the smartest of dinosaurs, we can add troodons — small to medium-sized theropods with long, grasping fingers, a tooth-filled snout, and a relatively big brain.
Looking at our list, no particular body plan seems to be favored, but all are symmetrical in their anatomy. The evolutionary reason, according to a recent study, is that symmetry requires less information for DNA to encode and allows more flexibility to develop future traits that may be advantageous. Even if aliens were to use another genetic carrier besides DNA, the same principle should hold.
To read more, click here.