To tackle this subject without first looking at the history of our planet and our own evolution is to ignore the only examples we possess which can
even begin to illuminate our thinking.
Our own Evolution
The Earth as a recognisable planet is thought to be about 4.5 billion years old
. It would
have been a molten swirling mass unrecognisable from the blue, green planet we know today.
As the earth cools we see the first biochemical evidence around 3.85 billion years ago
, and the oldest microfossils date to around 3.5
billion years ago
. There are many different theories as to what catalyst set the wheel of life in motion they range from a meteorite strike
bringing with it the building blocks of life to intelligent design, the most widely held theory is that life on Earth may have emerged in undersea
thermal vents in oceans. Most scientists now agree that heterotrophic bacteria were probably the first life on Earth. They absorbed the organic
material that was being created by the reactions of Earth at the time including amino acids, the building blocks of life, which created new organisms
and also acted as a food source.
Evolution is never static and with the first life came constant change, adaption, and colonisation.The autotrophs absorbed carbon and light while
excreting Oxygen thus changing over millions of years the enviroment they inhabitted.
It would be over 3 billion years later
at the beginning of the Cambrian geological period, around half a billion years ago, that the first
multi-cellular organisms began to appear, particularly in the form of sponges. It was not long after that that the first primitive animals evolved
leading in time to worms, molluscs, corals, anenames, and starfish.
Arthropods are the next step in marine animal evolution they are characterised by possessing jointed limbs and an exoskeleton. Crustaceans are a very
good example of the first Arthropods which were also the first species to exhibit more advanced receptors in the form of eyes (photo-receptors).
At this time plant life in the oceans is abundant and it is able to colonise the shoreline after it evolves the ability to bio-synthesize lignin, a
chemical process that allows the formation of a plant cell wall which retains moisture and counters the effects of gravity on land. The Arthropods
evolve themselves to take advantage of this new food source and an environment with few predators. These first land animals were probably similar to
millipedes. Fossil evidence dates the first land Arthropods, millepedes, to 428 million years ago
. From this point land plant life and
Myriapods, Arachnids and later insects colonise the land interior. The plants to avoid light and land competition, the insects to take advantage of
the expanding food source and the Earth begins to resemble the blue, green planet we know today.
Meanwhile, back in the oceans the first fish are evolving. These are invertebrates (without a backbone) which have evolved from primitive crustaceans.
Later vertebrates (with backbone) evolve after the evolutionary innovation of cartlidge.
From these fish vertebrates the first Amphibians evolve and with the first primitive lungs continually evolving they spend more and more time on land.
Once again they take advantage of the new untapped food sources on the newly colonised land. Amphibians, though they venture on land, rely on water
still to spawn and the young do not leave that water until adulthood.
Two evolutionary adaptions are needed before these Amphibians evolve into the first true land vertebrate, the Reptiles. waterproof skin (so that they
do not lose moisture) and shelled eggs (which provide a moist, nutritious, and relatively safe environment as opposed to the oceans teeming with
The first distinct dinosaurs occurred within the beginning of the Triassic Period, around 230 million years ago
. Dinosaurs, were the most
advanced reptiles of all time, due to the fact they were allowed to occupy as many ecological niches as they could without much competition in any
But even as dinosaurs became more and more diversified and became in some cases bigger and stronger, a new classification of species was evolving that
would usurp the dominent dinosaurs. These were the first mammal like creatures it was not less than 200 million years ago
that the first
distinctive differences were being noticed in species. But it was not until only 65 million years ago
that the first true signs of mammals were
to appear as a distinct class of species (probably small vole like creatures). They were warm blooded, not cold blooded like the reptiles and
dinosaurs and they did not lays eggs but carried the young inside them until birth.
Coincidently, or not, 65 million years ago
is also the time at which we see the disappearence of the dinosaurs. Whatever the cause of their
extinction it's clear that the mammals quickly filled the ecological vaccume left by the dinosaurs.
Continuing on our journey to our own present it was between around 6 to 8 million years ago
that the first hominids diversified from the apes.
This evolution from apes to hominids is not defined by any increase in intelligence but by the development of bipedality (an upright, two-legged
As you can see by the diagram above the hominid evolutionary tree leading to Homo-Sapiens is not without redundant branches.
Australopithecus, which was definitely bipedal is dated to around 4.2 million years old.
Australopithecus afarensis existed between 3.9 and 3.0 million years ago.
Australopithecus africanus evolved around 2.9 million years ago
. The cranial capacity of A africanus varied from 375 to 500 cc.
Both Australopithecus boisei and Australopithecus robustus are redundant branches of the hominid evolutionary tree which existed between 2.2
million years ago to 1 million years ago
. Both had an average brain size of about 530 cc.
Though also a redundant branch, Homo habilis marks the first example we have of a hominid with humanlike abilities. It is distinguished from the
australopithecines by evidence of tools found with him. Homo Habilis existed between 2.4 and 1.5 million years ago
. The species is still
primitive looking, but the teeth are smaller and the brain size is much larger that in australopithecines at 650 cc. The brain shape is also more
humanlike and Homo Habilis likely was capable of rudimentary speech.
Please note from the diagram above that around 1.9 million years ago
it was possible that at least 5 different and distinct species of Hominid
were contemporaneous. Hominids may have been competing for survival.
A similar competition existed as little as 400,000 years ago
when as many as 4 hominids, including Homo sapiens, were contemporaneous. Homo
erectus lived between 1.4 million and 300,000 years ago
. It was a successful species for a million and a half years. Early examples had an
average brain size of 900cc later examples are larger at about 1200cc. The species definitely had speech. Erectus developed tools, weapons and fire
and learned to cook his food.
Homo neanderthalensis Pre-existed Homo Sapiens by 200,000 years but lived contemporaneously with the Modern man for at least 90,000 years until the
Neanderthal disappeared 30,000 years ago. The Neanderthal is similar to Homo erectus except having a larger brain of around 1,500 cc, slightly larger
than modern humans which have an average brain size of 1350 cc. Thus proving that it isn't the size that counts but what you do with it that
The dawn of Modern man has not halted evolution within our own species. There has been a trend towards smaller molars, decreased robustness, less body
hair, and even an evidence of greater head circumference of newborns due to advancements in midwifery.
Evolution is in general driven by two distinct motors. Sex and Survival, although there are cases that the two appear to overlap. The Survival Motor
has produced the most marked evolutionary changes since life began but it is dependent on small gene pools either surviving in isolation or taking
advantage of new environments. This needs to be explained a bit more carefully. Small isolated gene pools are more likely to throw up genetic
mutations many of these mutations would be redundant but a few might be advantageous and those that are advantageous are more likely to be perpetuated
until a distinct new species has evolved. The Survival Motor is the most powerful force for evolutionary change but, relying as it does on the real
possibility of extinction, it is dangerous and acts sporadically only when breeding population numbers are small and survival is threatenned. The
Survival Motor is the great stride as opposed to the slow shuffle of the Sex Motor.
The Sex Motor, on the other hand acts continuously, it is relentless and can even be seen in the choice of spouse you choose to have children with.
Attractiveness is not just a question about asthetics. It is a complicated choice where subconsciously we calculate the health, and childbearing,
childcaring, or provider abilities of a mate.
But there is another evolutionary motor which only we, and perhaps our most recent Homo ancestors, possess. This is the Intelligence Motor, a
distinctly different evolutionary driver which steps over the line between natural selection and into artificial improvement. The increase of head
circumference of newborns is a good example. This is knowledge changing our own biology. Midwifery, from it's primitive beginnings right up to the
high tech scanners and surgery of today is allowing the gene pool to extend artificially.
That brings us up to the present day and it's a good place to stop and start looking at alien
evolution. It is impossible to comprehend in what other environments life might start but what we can be sure of is that life is possible in similar
environments to Earth's. This may appear to show a lack of imagination on my part but it is a sound beginning to tackle this question. Remember also
that the Earth, when life first started, was extremely inhospitable. When the autotrophs first absorbed carbon and light and excreted Oxygen 3.5
billion years ago they started a process of climate change which transformed the Earth into the green and lush planet it is today. Without them, and
the multi-cellular plants that followed, the Earth would have no oceans, no atmospere, and no hope of supporting life.
There are, no doubt, life groups other than the ones here on Earth (Bacteria, Fish, Insects, Amphibians, Reptiles, Birds, Mammals, and Marsupials)
others may evolve in the future, some, because of circumstances, never had the opportunity to evolve so let's look at those we know and see if they
might have evolved into the position we hold today if the circumstances had been different.
We'll take 4 evolutionary markers as our guide. The first is basic life (Which all achieved on Earth), the second is land domination, the third is
sentience, and the fourth is space exploration (a marker we have only recently passed).
It might seem a little unfair to set as my second marker land domination when fish have dominated the
lakes, seas and oceans for over 400 million years but without it there can be no fire and without that no metal working. Yes, it is possible that
volcanic vents could offer an alternative but fire must be controled before it offers any advantage. Fish have dominated our waters for over 400 years
and in that time made no visible steps towards intelligence. If they haven't done it by now it's hard to see how they could get there given that
they already dominate a huge environment with very little competition.
Insects only had a relatively short time on land before Amphibians and Reptiles joined them. If they
had had longer could they have evolved to dominate the land ? Quite possibly, yes. There would have had to have been a number of evolutionary steps
but it's not hard to see that given no competition animals descended from Insects might have filled every ecological niche on land and increased in
size. It's not hard therefore under these circumstances to imagine an insect descended tree dweller following a similar evolutionary path as us.
Insectoids (not a term for simply giant insects but a term for an animal group one or two evolutionary steps beyond insects), might well have evolved
both intelligence and eventually the ability to leave Earth.
Ants milk aphids for a sweet secretion known as 'honey dew'. The first picture (left) show an ant moving an aphid to a new 'pasture'. The second
show an ant tending and milking an 'herd' of aphids
From history we know that reptiles/dinosaurs dominated the Earth, infact, it was only after their
demise, 65 million years ago, that mammals had their chance. The range of dinosaurs filling every niche and more that mammals occupy now makes it hard
to imagine that a Reptoid (again not giant reptiles but an evolutionary branch from them.) could not have followed the same evolutionary path as
humans and so they too might have evolved into an intelligent, space faring species.
An intelligent species descended from Marsupials ? It's not impossible. They evolved quite along way
in isolation from mammals in Australasia and under different circumstances on another planet could evolve to become the dominant animal type.Could
Kangeroos already bi-pedal and surpringly dextrous have been the ancestors of an space faring species if circumstances had been different ?
If we exclude our own species from the picture might another mammal with a different evolutionary path
have filled the vaccume left by us. Bears for instance have evolved into many sub-species some often stand on their hind legs and use their
forelegs/arms to undertake tasks that require dexterity like fishing. Without primate competition mightn't they have become an intelligent species
given enough time ?
There are two more classes of aliens that I want to go on to explain. The first is a new animal type
that might evolve if humans and other land animal became extinct. The ancestry of marine mammals especially the more advanced ones like porpoises and
whales is quite remarkable. Having left the oceans as amphibians, followed our own evolutionary path through reptiles and mammals, they once again
took to the oceans and adapted the four limbs they would have had on land so that today they are atleast the equal of anything else in the ocean.
Intelligence-wise they are far ahead of any fish and locomotive-wise they are atleast the fish' equal. If the land became inhospitable for a short
period so that higher life forms became extinct and if these marine mammals survived might they not return to the land once more to take advantage of
the new opportunities that would arise there ? And if so might these masters of evolutionary adaption with their already well developed intelligence,
given time, evolve to equal our own achievements ?
How could a parasite become a space faring species ?
Let's take an example here on Earth. The sheep-liver fluke, Fasciola hepaticaa
. A fluke is a wormlike parasite that is evolved from the
flatworm and related to the tapeworm.
Until 1963 it was generally accepted that this animal used only the mud snails as intermediate host. However, it was discovered that the fluke
as a cercarian [larval or immature] form does not willingly leave the snail's body. It is ejected.
The snails embed the cercariae in balls of mucus and expels them. These balls of mucus are devoured by another intermediate host, the ant.
In this insect they encapsulate in the abdominal cavity and mature to the form that is so dangerous to the sheep's liver. The question is, how do
they get from an ant's stomach to a sheep's liver?
Clustered together, the infected ants hang for hours, offering themselves to be eaten by sheep or cattle, who of course oblige.
By a very strange process indeed. A single cercaria works its way to the brain of the ant and "takes over." Henceforth the ant is an automaton of a
kind it was not intended to be. Under the direction of the primitive creature dominating its nerve center, the ant is compelled to do things it would
never dream of doing. It climbs to the very tips of grasses and weeds and waits there. Clustered together, the infected ants hang for hours, offering
themselves to be eaten by sheep or cattle, who of course oblige.
An advanced and even intelligent parasite might not have to evolve physically as we have had to do. It could control the body of a physically well
adapted animal instead. This relation may well become symbiotic after time or each host animal might just be a stepping stone as better suited hosts
Ergonomic: The applied science of equipment design, as for the workplace, intended to
maximize productivity by reducing operator fatigue and discomfort. Also called biotechnology, human engineering, human factors engineering.
The process of evolution is designed to find the best answers to every environmental situation life encounters.
Before looking further at the question of alien evolution it is well to point out that natural evolution given enough time often comes up with the
similar answers to the same environmental conditions. The eye (often the bête noire of creationists) has evolved no less than 8 times independently,
if we include serviceable image-forming eyes (photo-receptors) then that figure goes up to between 40 and 60 times that we know of. This is a prime
example of nature, when faced with a blank page and from different starting points, finding the same solutions to the same problems. It is not just
possible that alien life form would have eyes it is highly improbable that they would not.
Another example of evolution finding similar solutions to the same problem is found in Seals and Sea lions.
The Leopard Seal, above left, is thought to be descended from otter-like ancestors whereas the "eared" seals like the sea lion, above right evolved
from bear-like ancestors. This is a very good example of nature, starting from completely different points finding the same answers to the same
environmental problems. So much so that most people can not tell the two apart and would be surprised to find out that their only common ancestor was
probably one of the earliest vole-like mammals. They diverged for millions of years before re-converging to adapt and survive in a the same
Primates evolved into hominids when they became bi-pedal. This freed our upper limbs so that we could undertake tasks that required greater dexterity
at the expense, it must be said, of speed of locomotion. Other mammals, marsupials, or reptiles would almost certainly have had to make this same
innovation. Insectoids needn't of become bi-pedal. With six limbs they could have evolved to be quadrapedal and still have been able to free up two
limbs which could evolve into arms and hands (of a sort). Or they might have freed up four limbs for this purpose and become bi-pedal like us.
Arachnoids with 8 limbs might have thrown up several combinations of multiple legs and arms.
On meeting an alien we may well be so overwhelmed by it's physical unfamiliararity regardless of any
physical similarities to ourselves (NB: we still react subconsciously to other human beings with different colour skins or a physical disability) that
we will fail to understand how instinctively different they will be to ourselves. Having spent upwards of 200,000 years in isolation from other
species with a remotely comparible intelligence we would face the biggist culture shock of our existence. Our natural assumption would be that a
common bond should exist between two intelligent species when they met.
However, we may not only look different we will almost certainly think differently. Our evolutionary origins define us still as a species today. We
are still apes, even if we are sophisticated apes and there is still considerable disparity between our instinctive behaviour and an ideal utopian
social order. We may say that we do not wish to live in an ideal utopian order because it might restrict indivuality but safeguarding that
individuality is instinctive in itself.
As a species we have tried grand social experiments which are the product of high intellectual thought, like communism, and found them contrary to our
ape instincts. On the one hand we can understand the benefits that such a social order could bring but on the other we are unable to live within them
on a day to day basis.
We are a schizophrenic species struggling to adapt to a global society continually changing in part due to our own accelerated technological
achievements while still carrying the instinctive baggage of our primitive primate ancestry.
Our laws may seem sometimes to be an effective restraint on some of our more base instincts but those laws are designed not to impinge too heavily on
them incase all order might be lost.
An alien species which has evolved from a quite different type of animal other than an ape will have quite different instincts concerning issues such
as breeding, feeding, rearing young, and fighting. We fight for monkey values. Insectoid values would be quite different almost to the point where it
is useless to try and speculate what instincts an insectoid might retain despite intelligence and technological advancement. An alien descended from
ants might have a rigid social heirachial structure and little regard for individual life but what about a preying mantis, cockroach, or a wasp ?
The differences might appear illustratively stark when we compare ourselves to a possible Insectoid race but they will be no less complicated if the
alien species were to be descended from bears.
If our different individual country's perspectives are defined by our history, what differences might there be if our evolutionary ancestry were so
The Intelligence Evolution Motor
I've already touched on this issue in passing above as regards midwifery and
newborn head circumference but now it's time to look at it more detail.
What defines us as modern mankind is our use of tools but we have approached a different era of our species where the tools are beginning to define
us. Our quickly accelerating technological achievements are changing our biological make up. Whether it's fast food, advanced medical techniques, or
global communication we are beginning to change, atleast in the devoloped industriaised areas of the world.
Global communication means that cultural and linguistic diversity is diminishing and we are becoming homogeneous. We have a very large gene pool and
so, excepting in the event of a terrible global disaster, the Survival motor of evolution is not noticable. Instead our technological achievements
are, on the one hand, making us a weaker biologically becoming more and more unsuited to survival unassisted in the environments we inhabit, while on
the other hand fascilitating our future biological evolution.
Much has been said about alien races who if they were to make the journey to Earth would have to be more intelligent than humans. But it is important
to make the distinction between intelligence and advancement. An alien race with a longer history might well be more advanced but that does not mean
they are more intelligent. Imagine stepping into a time machine and going back 1000 years into our own past. You would seem more intelligent to those
you met. Now come back to our time bringing with you a newborn and put it in school. It is highly probable that after twenty years of learning there
would be no discernable difference between the child you brought back and his youthful peers.
Einstein once said that he was "Standing on the shoulders of giants." He was ascribing his revolutionary thoeries to the value of accumulative
knowledge. The appearence that you might be more intelligent than the people in the 11th century is only because you have a better understanding of
what is possible.
We have artificial hearts, hips, kidneys, and limbs. Those that normally would die live and perpetuate their genes. This means that we will probably
become more and more dependant on science and technology. It's difficult to imagine how an alien race would be physically effected by the prolonged
effects of the intelligence motor just as it's difficult to imagine how it will effect ourselves in the future.
But effects there will be.
Perceptions of Aliens in Popular Culture.
No one would have believed in the last years of the nineteenth century that this world was being watched keenly and closely by
intelligences greater than man's and yet as mortal as his own; that as men busied themselves about their various concerns they were scrutinised and
studied, perhaps almost as narrowly as a man with a microscope might scrutinise the transient creatures that swarm and multiply in a drop of water.
With infinite complacency men went to and fro over this globe about their little affairs, serene in their assurance of their empire over matter. It is
possible that the infusoria under the microscope do the same. No one gave a thought to the older worlds of space as sources of human danger, or
thought of them only to dismiss the idea of life upon them as impossible or improbable. It is curious to recall some of the mental habits of those
departed days. At most terrestrial men fancied there might be other men upon Mars, perhaps inferior to themselves and ready to welcome a missionary
enterprise. Yet across the gulf of space, minds that are to our minds as ours are to those of the beasts that perish, intellects vast and cool and
unsympathetic, regarded this earth with envious eyes, and slowly and surely drew their plans against us. H. G. Wells, War of the
Now would be a good place to stop and look at how Alien life forms have been portrayed in popular culture over the last 50 years or so. As you will
see these perceptions say more about us than they do about extra-terrestrial life but it is interesting none the less.
Invasion of the Body Snatchers 1956 (left) and Invaders From Mars 1953 (right)
Both these films were heavily influenced by the American political climate of the time. They are as great a political comment about McCarthyism and
the Communist threat as 'The Crucible' by Arthur Miller. In both average people are turned into either have their identities stolen or become alien
'Body Snatchers' terrified an already paranoid American public and is still a scary concept today. It has been remade twice. In it the world is
replaced by alien doubles created in pods who are imperceptable from the originals people. This might be a good example of a parasitic alien.
'Invaders from Mars' is slightly different. In it probes are inserted into the necks of victims who then are controlled by the alien.
The interesting thing about this film, for our purposes, is that the main alien (pictured) has evolved using technology and appears to be unable to
function biologically without that technology. It is served by drone-like aliens. These drone-like aliens could be either victims from a previous
conquest or the product of genetic engineering undertaken by the superior alien race.
The Day The Earth Stood Still 1951(left) and The Blob 1958 (right)
Two of the sillier sci-fi creations. A bi-pedal robot and a giant predatorial gelatinous blob.
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Star Trek 1966. Spock: Vulcan (left), Klang: Klingon (centre), and Balok (right)
The imperative for how these aliens looked was the human body. Though Balok only appeared on the monitor screen and looked like a puppet rather than a
man in makeup and a suit. Vulcans and Klingons played a regular part in the series and they couldn't be too complicated. If evolution does find
similar solutions to similar problems then they may be closer than they initially thought. Balok looks so much like a 'Grey' that it would be silly
not to comment on it. He only appeared in one episode but a still was used in the credits. It may be that witnesses of 'Greys' may be
subconsciously recalling the image they regularly saw on TV in childhood.
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ET 1982 (left) and Star Wars 1977 (centre and right)
Over a decade on and the creators of fictional aliens are starting to think more about how their aliens evolved. ET is a quaint botanist but he
doesn't strike me as convincing. Neither do I find the Star Wars aliens convincing. It's difficult for me to put my finger on it but although great
strides have been made in credible alien physiology their character difference from humans is not imaginative enough probably because I've met people
like Chewbacca and Attila the Hutt.
Predator 1987 (left) Alien 1979 (centre) Independence Day 1996 (right)
These are amoung our most realistic interpretations of what aliens may look like. The big game hunter Predator appears to have evolved from a kind of
Insectoid it is technologically superior to humans. A very realistic portrait.
Alien, a non technologically advanced alien race with a vicious and uncompromising survival instinct. It is only space faring because some advanced
species visited it's home planet. Probably an insectoid.
Independence Day alien. Another technologically advanced Insectoid with an exoskeleton.
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Star Trek, The Borg 1996 (left) Terminator 1984 (centre) and Matrix 1999 (right)
OK, before you say anything only one of the above is alien but there is an important reason why I've included the others. Could the next rulers of
the Earth be the very technology we create ? We are making great strides in Artificial Intelligence but what might happen if machines become self
aware and taking over. Will they be as eager to exploit us as we are to exploit them ? Artificial Intelligence seems to me to be a legitimate
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The Grey (left), The Reptillian (centre), and The Nordic (right)
The most common aliens described by 'witnesses' and 'abductees'
All are credible as far as evolution is concerned.
So Why Haven't We Been Visited By Aliens Until Now ?
As you can see from the map below we are on the fringes of
the Milky Way galaxy. Nearer the congested centre different alien life forms are probably interacting aalready.
*We are nothing special.
*We have no resourses of value (atleast that would merit the journey)
*We're not on the way to anywhere interesting either.
Other species may have encountered intelligent life on planets in their own solar system. Imagine if Mars was a twin of Earth. That would be a huge
headstart for any Intelligent species.
Some space faring races may never have left their own planet if it had not been for visitors. Therefore artificially accelerating their
Personally, I like living in the quiet part of town. You just don't know your neighbours might be.
[edit on 22-6-2005 by John bull 1]
[edit on 22-6-2005 by John bull 1]