Speculating about what aliens might look like has inspired artists and film producers over the years , If aliens do exist would they look similar to
us? Unfortunately, we can’t study extra-terrestrial life to answer this question. But we can study 4.6 billion years of Earth’s history, All
existing life on earth had a single origin 3,5 Billion years ago which started to randomly diversify into more complex organisms until super
intelligent humans eventually came into being.
But what if we turn back the clock and allowed life to evolve again? Most likely we would not look the same. If you change one small thing in the
early stages of evolution then the consequences will magnify through time.
In the version of history we know, The 2 eyed Haikouichthys survived and ultimately gave rise to fishes, amphibians, reptiles, mammals and ultimately
If it had perished and some other group like the 5 eyed Opabinia had given rise to intelligent beings then chances are you would probably be reading
this with five eyes rather than two.
Evolution of humanoids
To understand the evolution of humanoid lifeforms we need to look at how primates evolved here on earth. All primate species possess adaptations for
climbing trees. although not all species are arboreal. Some characteristics of primates are possessing large brains, claws that have been modified
into flattened nails, only one young per pregnancy, stereoscopic vision, and a trend toward holding the body upright.
The first primate-like mammals evolved in the early Paleocene Epoch (65.5-55.8 mya) at the beginning of the Cenozoic Era and were roughly similar to
squirrels and tree shrews. During the Eocene epoch these tree dwelling critters would later evolve into prosimians (such as lemurs and tarsiers) and
during the Oligocene Epoch (40 mya) Prosimians would then evolve into monkeys.
There are two types of monkeys known as “Old world monkeys” from Africa and ‘New world monkeys’ from South-America. Apes evolved from old
world monkeys in Africa midway through the Cenozoic, approximately 25 million years ago , Around 7 million years ago these apes would later evolve
into Hominids that had the ability to walk upright.
Sometimes evolution repeats itself with different species independently converging on similar outcomes this is known as Evolutionary convergence.
examples of convergent evolution are Australia’s extinct, marsupial wolfs that have a kangaroo-like pouch , There are also marsupial moles,
marsupial anteaters and marsupial flying squirrels. Other striking cases of convergence include dolphins and extinct ichthyosaurs, which evolved
similar shapes to glide through the water.
Some prehistoric mammals like Chalicotherium , Anisodon and Archaeoindris have also evolved somewhat similarly to great apes with extremely long
limbs yet none of them are related to anthropoid primates.
Building stone tools contributed a lot to our intelligence which required a large brain and apposable thumbs. Apes have managed to developed tool use
to a great degree. This is at least partly the result of walking on two legs, which frees up the front limbs, and because of the dexterity of our
fingers, If this evolutionary process worked for hominins it should work for other animals as well.
Popular Types of aliens
Humanoid Aquatic Aliens
Most people forget that marine mammals like dolphins and whales evolved from land mammals that had adapted from an aquatic environment.
According to the “Aquatic ape theory” ancestral apes were forced by competition to leave their natural habitats and feed on the seashore searching
for oysters, mussels, crabs, crayfish where they would have spent much of their time foraging under water.
There are so many hypothetical scenarios where early hominids would be required to adapt an aquatic lifestyle. But what are the anatomical changes
that would follow?
• Like most aquatic marine mammals the aquatic humanoids will develop 18-20% body fat which will mainly consist of blubber for insulation to survive
in cooler waters. Unlike normal fat Blubber is much thicker and contains many more blood vessels than the fat found in land animals. Since hair would
serve no purpose for thermal regulation the sweat glands would disappear , the outer layer of the skin would then become thick and smooth to allow
better movement through water.
• Partial feet and hand webbing with additional fins would also help to move through water much faster.
• Through natural selection carnivorous teeth would enable the aquatic humanoids to successfully pass on their genes as a result of selection
pressures for resources.
• Like all marine mammals , aquatic humanoids would develop muscular flaps around the nostrils to cover the respiratory tract ensuring water does
not enter lung activity.
• Increased volume of red blood cells would store more oxygen enable long dives for prey
• The movement of the ears closer to the eyes is also part of the evolution process
Humanoid Insect aliens
What about the large brained and intelligent creatures that might be capable of crossing interstellar distances? Insects are by far the most species
rich group on Earth: why shouldn’t aliens look more like them?
Unfortunately, having your skeleton on the outside makes growth difficult, and requires periodic shedding and regrowth. Since Insects have
exoskeletons made out of chitin the composed material could cause the exoskeleton to become more brittle and more likely to break , insects larger
than 3 feet would become extremely vulnerable and would become too slow to even move. On Earth-like planets, all but relatively small terrestrial
animals with chitin based exo-skeletons would eventually collapse under their own weight during moulting.
There are two ways reptiles could evolve into humanoids.
They could either start climbing/swinging on trees like primates and start developing long fore limbs and a bulky torso like apes or through the
process of convergent evolution they might evolve into the shape of an ape and gradually start walking upright.
Whether reptiles unlike mammals have the brain capacity to start using stone tools is debatable. Scientists have proven that some dinosaurs like
Troodon had a brain that was gradually increasing in size. But the rate at which a reptile’s brain evolves is much slower than in mammals. Some
scientists like Dale Russel have speculated that If the Troodon dinosaur survived the mass extinction event 60 million years ago and was alive today
it would have had the brain capacity of 1100cm which is the same size of a small human. Since there are no intelligent reptiles alive we can only
Would aliens also have lips like us?
When we compare human lips to those of our nearest relatives, there are several differences: the existence of a philtrum and the "fleshy" red lips
which is covered with mucose instead of skin.
It’s still a mystery how humans still have a philtrum since it serves no purpose
edit on 8-1-2020 by Time4Nostalgia because: (no reason given)
edit on Fri Jan 10 2020 by DontTreadOnMe because: edits per OP