Convergent Evolution and Alien Life

The latest episode of the Skeptics' Guide to the Universe features an interview with evolutionary paleo-biologist Simon Conway-Morris. Dr. Conway-Morris participated in the Royal’s Society recent symposium on alien life. In the interview Dr. Conway-Morris discusses his talk on convergent evolution in regards to alien life. Dr. Conway-Morris theorizes that aliens may not appear “alien” but will have many similarities to humans. This does not necessarily mean they will be bipedal and humanoid. Conway-Morris says that looking at life on our planet, we see nature tends to find the optimal solution to challenges faced by life. Even in distantly related groups the same sorts of solutions can be found. Based on this, Conway-Morris speculates the same may hold true on other worlds. Life on these worlds may find the same solutions to challenges that life on Earth does, although the details of how these solutions are achieved may be different. Conway-Morris also discusses extremophiles in regards to the evolution in alien life. He believes that extremophiles represent not only the limits of terrestrial life but all life, and life on other worlds may need similar to conditions to our own to thrive. However, Dr. Conway-Morris cautions that we are working with only one data point and cannot test these theories until we find an alien bio-sphere.

Those interested in listening can find the Skeptics' Guide on iTunes or at their website.

Good Post

I've always thought, according to the traditional scientific view on the possibilities of extra-terrestrial life, that life on other planets would be quite similar to ours.

Seeing as how traditional science limits it's search possibilities to "Earth-like planets"; i.e. same distance from star, same type of star, same atmosphere, ect., it would only make sense that life would adapt to such a similar environment in the same way it adapted to Earth's environment.

Of course, as the article states, this wouldn't mean identical species, but simply similar evolutionary traits.

Originally posted by Monts
Good Post

I've always thought, according to the traditional scientific view on the possibilities of extra-terrestrial life, that life on other planets would be quite similar to ours.

Seeing as how traditional science limits it's search possibilities to "Earth-like planets"; i.e. same distance from star, same type of star, same atmosphere, ect., it would only make sense that life would adapt to such a similar environment in the same way it adapted to Earth's environment.

Of course, as the article states, this wouldn't mean identical species, but simply similar evolutionary traits.

Surely you understand the need for "traditional" space science to evolve beyond looking for life we would recognise? There could be races of beings living in the gaseous expanse of jupiter that you and I would mistake for mere clouds, or silicone based lumps of rock that have the intelligence of a thousand einsteins living on Mars under the soil. We wouldnt know how to examine one for life signs, but whos to say there isnt life of an unrecognisable nature out there!? The scientists need to start thinking outside the miniscule little box they have been poking around in for the last god knows how long!

reply to post by TrueBrit


thank you TrueBrit

i completely agree with everything you said there and IMO it's ridiculous to even think life found elsewhere in the universe that evolved on it's own would resemble humans. not saying it's impossible but the chances of E.T. life developing in a completely different biosphere and turning out like us is slim to none.

i believe we will never find another planet that is exactly like Earth.


[edit on 8-2-2010 by easynow]

Originally posted by TrueBrit
Surely you understand the need for "traditional" space science to evolve beyond looking for life we would recognise? There could be races of beings living in the gaseous expanse of jupiter that you and I would mistake for mere clouds, or silicone based lumps of rock that have the intelligence of a thousand einsteins living on Mars under the soil. We wouldnt know how to examine one for life signs, but whos to say there isnt life of an unrecognisable nature out there!? The scientists need to start thinking outside the miniscule little box they have been poking around in for the last god knows how long!

You are making a massive contradiction. You admit such speculative life would be unrecognizable as life and have no idea how to even begin searching for it. Then you bash scientists for taking the pragmatic path in the search for life.

While you are right, such life may exist, we have no evidence for it. We do, however, have evidence that life can arise on Earth-like planets, even if that evidence amounts to only one data point. While we should explore the possibility of extreme types of alien life form, it makes no sense to sacrifice what we know, what we have evidence for, in exchange for speculatives we have no evidence for.

convergent features in evolution we see on earth suggest tech intelligence will be rare.

an obvious convergent feature is eyes. we see eyes in millions of species on earth nature just loves them. If we found complex life on another planet its likely they will have eyes of some sort.

So we can ask the question- is tech intelligence a convergent feature of evolution? The answer is a resounding no, its happened once in 2 billion years out of billions of species nature just doesnt seem very interested in intelligence. So i think to say tech intelligence is common in our galaxy is just plain wrong.

Originally posted by yeti101
So we can ask the question- is tech intelligence a convergent feature of evolution? The answer is a resounding no, its happened once in 2 billion years out of billions of species nature just doesnt seem very interested in intelligence. So i think to say tech intelligence is common in our galaxy is just plain wrong.

I don't think the answer is so cut-and-dry. Though I do agree with you, there is so much we do not know. For instance, what definition of "common" are you working with? And before we can answer your question, we should also ask if intelligence is inevitable? That is, allowed to thrive and given enough time, will life evolve intelligence?

Originally posted by easynow
reply to post by TrueBrit

 

thank you TrueBrit

i completely agree with everything you said there and IMO it's ridiculous to even think life found elsewhere in the universe that evolved on it's own would resemble humans. not saying it's impossible but the chances of E.T. life developing in a completely different biosphere and turning out like us is slim to none.

i also think we will never find a planet that is exactly like Earth.


[edit on 8-2-2010 by easynow]

Considering we havent found a planet like ours yet doesnt preclude them NEVER being like our own... we've only just started to find them and only within the limit of our technology.

For all we know planets might evolve convergently just like life, planets in the Goldie Locks zone may for the most part be all similar to Earth, not exact, but displaying an environment or multiple environments similar to some parts of Earth, in that they are hospitable and recognizable. A desert world within the safe zone of its star, like Earths sahara would/could still have life like that found in the Earth environment equivalent, should life have developed on it to begin with of course. We know Mars had water and it sits in the same habitable zone earth does in relation to having a possible environment suitable to life, for all we know it may have been extremely similar to earth in its early days. If our nearest planetary neighbor can or used to be Earth like then id say expect to find ALOT of Earth like worlds out their, or worlds that once were Earth like.

Now, will life for the most part from a world similar to ours be recognizable... and by that I mean, you could sit their and say, 'Hey you look a little like something we have back home', or 'hey golley gee youve got fingers and toes similar to mine'. To my mind, of course it would... as to extreme forms of life, of course they will be there as well, no ones saying they wouldnt exist. Their saying life will be like our own, plus. Your saying life will only be like the plus.

Its just that planets like our own, once we find them, give us the highest chance of recognizing life like our own. First thing we need to establish is are we unique?, and the easiest way to find out is to find others similar to ourselves (and by similar I mean if we found a communal rodent like creature on a world where it built rudimentary structures from dry mud and it displayed some form of culture that would in my mind constitute sufficiently similarity) , once we establish that THEN start looking for life in the extreme range, such as sentient rocks and gas clouds... if you go the other way around, you might spend centuries showing glowing rocks Rochette diagrams only to find out it was nothing but a glowing rock.

Originally posted by yeti101
The answer is a resounding no, its happened once in 2 billion years out of billions of species nature just doesnt seem very interested in intelligence. So i think to say tech intelligence is common in our galaxy is just plain wrong.

Only if you think of it from a Human perspective, of course from a human ideal of 'intelligence' everything else is an animal... watch a spider build a new web, watch it work out where a good location for a web is, watch it work out where it needs to lay down the starting strands between the available branches for the best bracing, then counter braces these, then every thing else. Kind of reminds me of something I read where they had taught a gorilla sign language (wasnt Coco I dont think), it was asked questions and one involved a choice between a house or a tree as a dwelling... the gorilla choose the tree, and they crowed that it wasnt intelligent enough to recognize the benefits of the house. The thing is, why would a gorilla want a house?.. they judged its intelligence based on a human ideal... it was intelligent, they just didnt understand how it reasoned.

I live with 9 cats (ive lived with multiply animals all my life), I watch them daily interact with human and non human alike... their intelligence is no different than our own, its just taken from a different set of rules, rules that work for them.

As to the billion years and only man has risen to the top, you do realize that over that period of time, life on earth has been wiped out 3-4 times to the point where virtually nothing was left?.. if some other life form had developed to an early form of civilization as we understand (or accept) it or even higher, very little if any of it would remain... only to be trodden under by the rise of new life that came afterwords. Man went from effectively an 'animal' to space rockets in a few hundred thousand years... which is nothing but an insignificant fraction of the time our Earths been spinning.

For all we know 'human' intelligence may be one of a thousand previous ones like it on earth... to think otherwise in my mind is arrogance. If that is the case... what of life every where else in the universe.


[edit on 8-2-2010 by BigfootNZ]

reply to post by BigfootNZ

Considering we havent found a planet like ours yet doesnt preclude them NEVER being like our own... we've only just started to find them and only within the limit of our technology.

i didn't say there are no planets exactly like Earth, i said we will never find one. it's certainly possible to find one that has some similarities but the chances of finding one (with our current methods) that has the same type of atmosphere with a oxygen and carbon mix and temperatures exactly like ours that is breathable to humans is IMO less likely.

that could be one of the reason the ET's that have visited this planet don't land on the Whitehouse lawn or interact with humans the way we think they would. if there was alien life living in the Oceans of Europa and they visited Earth , where is the more likely place they would go or for lack of a better term, be more comfortable ? if something like that were the case then i would speculate that the Oceans on Earth would be more suitable for them and that might explain why there have been so many USO/UFO/UAO sightings of craft coming out of the water.

Your saying life will only be like the plus.

i said it's not impossible , didn't i ?


[edit on 8-2-2010 by easynow]

reply to post by DoomsdayRex


SETI goes for common and they put a minimum of 10k civs in the galaxy. Even then the closest is 1000ly away. They never mention a maximum these days.

Rare would be 10 civs max.

Is intelligence inevitable? I dont think so. It took 3 million years for our brains to evolve from primitive ape like creatures. The dinasaurs had 150 million years but didnt evolve an intelligent species. I still hope complex life might be common but i think it will mostly be no smarter than a monkey. Hopefully lots of planets for us to colonize

reply to post by BigfootNZ


it would be cool to have all those earth-like planets but i think only a precentage will have complex life.

For all we know 'human' intelligence may be one of a thousand previous ones like it on earth... to think otherwise in my mind is arrogance. If that is the case... what of life every where else in the universe.

that would be nice but we have no evidence of any previous civilization. We could find the signs like primitive tools or weapons, we have fossils hundrends of millions years old from alot of species none has the brain big enough to be intelligent. Humans already have left a premanent mark on earth even in billions of years you would find a layer of concrete in the rock strata, we find no anomolies like this when we look today.

it looks like we are the first intelligent civ on earth.

[edit on 8-2-2010 by yeti101]

Originally posted by easynow
I didn't say there are no planets exactly like Earth, i said we will never find one. it's certainly possible to find one that has some similarities but finding one that has the same type of atmosphere with a oxygen and carbon mix and temperatures exactly like ours that is breathable to humans is IMO less likely.

While I will agree with you, ill also disagree with you. From a human stand point we're a very adaptive bunch (along with most life), we lived and still do, in very primitive existences in the frozen wastes and the baking deserts for thousands of years. If sentient alien life is in anyway just as adaptive then I think the habitable zone for life like our own is far larger than we give it credit. As such I think that the term 'earth like worlds' can be just as broad, a frozen world like a global Siberian tundra is still habitable, livable and still Earth like, just more narrower, extreme yes but not impossible.

Atmospheres I sort of ignore, since alien life could be like us but have a completely different system for breathing, environment extremes (minus atmosphere) are in my opinion the bigger clinchers, although atmosphere can play a big roll in molding the environment. What about an Earth like world where oxygen due to the atmosphere or some other system, is pooled into pockets within valleys and other similar places... is such a world sufficiently human habitable?, its not perfect but it has micro earth environments, the thing is could we ever detect it, or brush it off as a world with a thin or non existent atmosphere. Life like our own, doesnt require all the systems we have on earth. Which is what I was arguing, I got the vibe that you were saying, since the chance of finding other planets like our own is so small the chance of find life that evolved similar to our own on these worlds is just as rare. Im stating that the boundaries of what constitutes a world like Earth can be stretched a good distance, as such theirs alot more habitable (but hardly comfortable) worlds than we think.

Originally posted by easynow

i said it's not impossible , didn't i ?

Yes sorry about that I was being a little absolute when reading your post, I tend to sit on the fence on things like this, since its so large I go with the middle idea that every thing is possible to a degree. I wont say alien life is only going to be human like or their never gonna be human like. Although from my own opinion I lean more to the they'll be more similar than not similar, although similar can be quite broad . As such for me, people on both ends of the spectrum are both wrong ... I guess thats me being lazy.

Originally posted by yeti101

that would be nice but we have no evidence of any previous civilization. We could find the signs like primitive tools or weapons, we have fossils hundrends of millions years old from alot of species none has the brain big enough to be intelligent. Humans already have left a premanent mark on earth even in billions of years you would find a layer of concrete in the rock strata, we find no anomolies like this when we look today.

it looks like we are the first intelligent civ on earth.

[edit on 8-2-2010 by yeti101]

The problem with that idea is that what we have in terms of fossils, just a small number of the total whole, we base everything on a small (and it is small when you think about it) number of fossils from a small number of sites around the world. yet attempt to paint a broad picture of prehistory of the globe. The only way you could be totally sure is if you scoured every inch of the surface of the earth, which just isnt going to happen.

As for proof (or at least possible evidence) of past extreme ancient civilizations, there are some... stone tools found at one site where found on or in a coal seem, in strata that placed them long before humans supposedly even existed. You then have the collection of metal ringed spheres that if you go with conventional dating basically put them as existing before life even started on earth!. You then have the fossilized finger case and the fossilized pick hammer that was found incased in rock, that was made of very pure metal that doesnt rust. If man kind was wiped out, in a million years nothing of ours would remain, or at the least nothing recognizable, we have no examples of million year old concrete so to say such things would be around as proof at that time is unfounded.

I also didnt say civilizations of our level only, but life may have gotten to 'cave man' status thousands of times in the past, and little of theirs would survive even 10 thousand years, let alone millions, if we even found it in the first place.

As for brain size to intelligence, that is a rather out dated concept. All things are intelligent, just to varying degrees. Perfect examples to me is a breed of spider I saw on a nature doco, not sure of its name. It hunts other spider species, and it learns and remembers through experience how to entice other species of spiders out of their webs through trial and error by plucking their webs, it remembers its successes and uses them on the corresponding species the next time it finds them... yet its brain is smaller than a pinhead. Id call that intelligence... hardly human, but its still analytical thought on its part. Also not to mention the tool use of Octopi and the learning capabilities of cuttle fish.

I still think the OP is correct, life on worlds similar (which doesnt necessarily mean exactly, or even mildly the same) would evolve along similar lines. Earths own environment has been different through out its life, yet every age of life that has lived through these variations in the global environment has thrown up creatures similar to one another in other ages for the most part.

Actually the latest Keppler data indicates there may be many, many planets that are very much "just like Earth".

Springer...

reply to post by BigfootNZ

Atmospheres I sort of ignore

the atmosphere is probably the most important thing to consider and imo it would dictate what kind of life would evolve on a Earth like planet.

i believe there are planets that are "Earth like" just as Springer has mentioned about the Kepler telescope supposedly finding but Earth and "Earth like" are two different things and it's highly unlikely that the atmosphere of these newly found bodies is composed of the same exact mixtures and ratios of oxygen, carbon and temperatures etc. found here and that means life will be different on all scales.

we might find hundreds of planets with oceans and a atmosphere but i am willing to bet any life existing on them won't look like us. of course i could be wrong



[edit on 8-2-2010 by easynow]

reply to post by BigfootNZ


I totally agree with you, I've always said that isn't it funny that in 2 billion years that all the animals predators and prey a like didn't form an intelligent society or culture but only the hominid/human did. I never bought that. I've always believed that over the course of live on this planet, there may have been more than just humans that became intelligent. I think that a form of dinosaur may have developed intelligence long before we dug out from our little mammalian holes, then they where wiped out and then something else or another group came along. I think that when we do find intelligent life or life in general it will be shaped by it's environment and the chances of fate (mass extinction, solar flare, Nova (never know) etc etc.).

reply to post by Monts

I've always thought, according to the traditional scientific view on the possibilities of extra-terrestrial life, that life on other planets would be quite similar to ours.

The usual arrogance of human being... What else could I say about the pathetic attempt of earthling scientists, to put an Earth-like standard to define other intelligent life forms among zillions of galaxies?? It's RIDICULOUS!!! It's just a silly way of handle with their fears. The fear of unknown, the fear of the different. "extraterrestrial life quite similar to ours"... WTF is that mean?? We evolved from primates, but just tell me what prevents intelligent beings evolving from felines, canines, insects, reptiles, amphibians or whatever??? Since a planet have environmental conditions to provide complex organisms and to increase their development to any possible biological direction, where's wrote in the "alien lifeforms handbook for dummies", that "intelligent lifeforms have to be similar to earthling humans"???? And when I say "environmental conditions", not necessarily have to be equal to the Earth, varying in gravity, atmospheric pressure, temperature, influence of different types of solar radiation, influence of one or more satellite's gravity, etc, etc, etc.
People are you serious??? What load of disinfo!! That's the same BULLSH*T propaganda made during the age of great navigations to (de)qualify those who weren't caucasians: "If your aren't European and caucasian, you aren't human." Now the same crap is being applied to extraterrestrial lifeforms issue. This makes me sick!!


[edit on 8-2-2010 by ucalien]

Anyone familiar with Dr. Crick? I was a student of Biology and Dr. Crick paired with Dr. Watson were the first to recreate the beginnings of life in a controlled environment. It was a beautiuflly designed experiment.

Originally posted by yeti101
SETI goes for common and they put a minimum of 10k civs in the galaxy. Even then the closest is 1000ly away.

Isn't that number not a minimum-maximum of total civilizations in the history of the galaxy but the number of communicating civilizations at any given moment?

Originally posted by yeti101
Is intelligence inevitable? I dont think so. It took 3 million years for our brains to evolve from primitive ape like creatures. The dinasaurs had 150 million years but didnt evolve an intelligent species...

I don't mean inevitable for a species but inevitable for a planet. It may have took 3 million years for primates to develop intelligence, but it took 300 million for mammals to develop intelligence. So, let me rephrase the question; presented with the same environmental stimuli that allowed for the development of intelligence here, is the development of intelligence on other planets inevitable?

From Conway-Morris' theory, we can extrapolate that it is an inevitability. Evolution will find a way. I think Dr. David Grinspoon makes much the same argument in his book Lonely Planets.

reply to post by TrueBrit


Yes, I agree with you completely to think that its narrow-minded to think that all extra-terrestrial life must occur in environments like earth. That is why I said "according to the traditional scientific viewpoint", which is what the article is based on.

That is why I noted that life would obviously be similar on earth-like planets; because they are very much like earth!

As others have noted, and that which I also think is true, is that it is extremely narrow-minded to think life only exists in the conditions that are "earth-like". There could be all sorts of life-forms that are not based on carbon (as we are).

Carbon is assumed to be the best element for life, seeing as it has the highest amount of bonds combined with the lowest amount of protons/electrons.

Silicon would be the second most optimal element for organic base, but nitrogen, methane, and even fluorine could also work.

There could also be basis for life that we can't even imagine yet, and life could literally be staring us right in the face in different forms that we can't even perceive or recognize.

Of course this is all speculation, but speculation is the path to discovery!