I have been facinated with Stephen Hawkins "Into The Universe" on the Discovery Channel. It is the most incredible program I have ever seen on Television and has opened my mind to the mysteries of Space. I am also at a transitional period in my life where I am questioning if there is a God or purpose to life so this is all very new and interesting. There are billions of Galaxies which contain hospitable planets similar to our own. I wonder if the laws of evolution partain to other worlds and if some of the higher forms of intelligence evolved into humans who look and act similar to ourselves. If modern Humans on Earth have only existed for roughly 100,000 years I would be curious to see Humans on other planets several million years ahead of us. That is if they hadn't already destroyed themselves by then.



Edited 2 time(s). Last edit at 05/19/2012 02:29AM by turnonthelights.

have all made statements of personal opinion that they think it is likely if not inevitable that life, and sentient life, occurs throughout the universe, and probably follows the same patterns of evolution we observe on earth.

Evolution repeatedly arrives at what Dennett calls a "good trick". Things like bilateral symmetry, wings, eyes, appendages, neurosensory function, motor function, etc., occuring more than once independently in our own biosphere. There seems to be naturally efficient forms for any given environment, and evolution naturally moves toward it.

One case study: the Tasmanian tiger. It was a wolf-like marsupial that evolved independently from possum-like ancestors, while wolves in the rest of the world evolved separately. They both arrived at a similar morphology matching their similar roles, even though there was no crossbreeding between them at all.

However, these gentlemen are also adamant that so far there has been ZERO evidence of life anywhere else, and that any/all such claims should be scrutinized with utmost skepticism.

turnonthelights Wrote:
-------------------------------------------------------
...
> if some of the higher forms of
> intelligence evolved into humans who look and act
> similar to ourselves.
...


The answer to your question may depend upon how far you
are willing to stretch the meaning of the word "similar."

Carbon-based organisms vs silicon-based organisms? -- or
Anaerobic organisms vs Aerobic organisms? -- warm-blooded
animals vs cold-blooded animals? -- animals with lungs? --
animals with gills? -- animals with wings? -- what?

Highly evolved intelligent entities that live in a liquid
environment (such as sea water) might not look much like
human beings at all. I'm thinking an octopus body, maybe.

I wouldn't expect for us to encounter Vulcans and Klingons,
nor blue-skinned Na'vi -- if that's what you're thinking.

On the other hand, if the number of galaxies in the
cosmos approaches infinity, then I guess there would
be quite a few humanoid populations, even if they only
constitute an infinitesimal percentage of advanced entities.

UD

Oxygen is what has allowed pretty much all complex life to evolve. It's like rocket fuel for life, without it the metabolism of life would be something like 40 times less efficient. Unless our anaerobic friends on another planet have stumbled on some other rocket fuel it's unlikely they would have evolved a brain complex enough to form a civilization.

I don't know, we do have life on our own planet that doesn't intake oxygen - plants. I don't see why aliens couldn't use photosynthesis or something similar instead of breathing oxygen.

Edit: I just looked it up and you're absolutely right.
"Because aerobic metabolism generates 18 times more energy (ATP) per metabolic input (hexose sugar) than does anaerobic metabolism, the engine of life became supercharged. This sequence of evolutionary steps enabled the emergence of complex, multicellular, energy-efficient, eukaryotic organisms."
http://www.pnas.org/content/98/5/2170.full

Amazing stuff.



Edited 1 time(s). Last edit at 05/19/2012 10:25AM by sexismyreligion.

A VERY small fraction of the Earth's biomass looks at all like us. Why would we expect life on distant planets to look like us?

As it was said, they might find a way to develop things like eyes or ears that we could identify as such, but it is unlikely they would look like anything we have ever observed. It's not going to be like Star Wars where you walk into a bar, and have a bunch of different alien species with the same number of appendages, all located roughly in the same place.

that we arrived out for ours, i.e. two hands, two legs, one head, etc. but it definately won't be human.

Why not Zoidberg!? Sorry I had to. . .

One thing any advanced life will need to be able to do is develop a way to record knowledge in an external format that can be easily shared. If humans had not invented writing I doubt we would have ever been able to achieve what we have. Which is why I doubt a water dwelling species like a Dolphin would ever evolve to the point where they could invent computers, or spaceships.

If our species ever does colonize the nearby planet of Mars, people who are born and grow up there are going to evolve differently than we do here on earth. Within the first generation there will be changes to their physiology that will be different than we are who stay here. It will only become more significant with each succeeding generation. I believe, and this is only Doctrine according to Dennis, FWIW, that at least some of the different life forms in the bar scene in Star Wars have common ancestors. Of course there is the fact that star wars is Doctrine according to Lucas, FWIW.

You are probably right. Unless the is frequent travel between the two planets with people from one moving to the other and interbreeding. But that will probably a limited set of people. They may even intentionally manipulate their dna in a way that allows them to survive on that planet.

We are tubes with holes at each end and appendages. So are insects, reptiles, bony fish and many other life forms. Not all intelligent, mobile lifeforms are tubes, but I don't picture star- and jellyfish types building vehicles for travel. Not any time "soon" at least.

Quite literally we are each a living torus. Like a donut!

Did you know that in the future a despot will punish you by teasing a small, very tough filament into your mouth, down your throat, through your stomach and intestines, and out your anus. Then that filament will be used to pull an increasingly larger line along that path until there's a rope strong enough to hold your body's weight and then you will be strung up and left to die: hanging mouth to anus, swinging in the wind...

It's true, I read it in a future magazine!

Remember when you first saw a tardigrade?

Check out these six nearly immortal creatures...

https://www.youtube.com/watch?v=W382U0baxVA


I think there's a bigger chance we'll find the remains of intelligent dinosaurs before we find Zarahemla.

If they look anything like Terry Ferrell did in Deep Space Nine I'm in....

The laws of the universe are universal.

The elements found on earth are very likely to be the majority of all elements found in the remainder of the universe and all other universes.

Other evolved systems on other planets would probably be similar to us because they would have the same elements available to them to develop and evolve and they would also have the same types of environments and lengthy time spans where those environments were stable as well as need the same advantages (senses, ambulatory, intelligence, etc.) that fauna on our palnet needs. Since their environments would probably be similar and they'd be carbon-based with DNA and need water for life, their flora would probably be similar as well.

Science currently offers theoretical evidence for the existence of a multiverse.
If such a thing exists, not only have Homo sapiens evolved independently many times on many planets, but so have the English language, the internet, and you yourself with brown eyes instead of blue on one planet Earth, green eyes on another planet Earth, etc.
In the multiverse, every possible reality exists.

Talk about inspiration...this afternoon, before I saw this thread, I was thinking about alternative forms that humanity could take. In particular, I was thinking of two extremes--either exoskeletons or external mucous membranes instead of skin.

Well that settles it then... It must be "true".

http://www.staff.science.uu.nl/~gent0113/huygens/huygens_ct_en.htm

"Nor does it follow from hence that they must be of the same shape with us. For there is such an infinite possible variety of Figures to be imagined, that both the Oeconomy of their whole Bodies, and every part of them; may be quite distinct and different from ours. How warmly and conveniently are some Creatures clothed with Wool, and how finely are others deck’d and adorn’d with Feathers? Perhaps among the rational Creatures in the Planets there may some such distinction be observ’d in their Garb and Covering; a thing in which Men are apt to envy the happiness of Beasts, tho perhaps without reason. For men might be born naked, only perhaps for the employment and exercising their Wits, in the inventing and making that Attire that Nature had made necessary for them. And ’tis this necessity that has been the greatest, if not only occasion of all the Trade and Commerce of all the Mechanical Inventions and Discoveries that we are masters of. Besides, Nature might have another great Conveniency in her eye, by bringing men into the World naked, namely, that they might accommodate themselves to all places of the World, and go thicker or thinner cloth’d, according as the Season and Climate they liv’d in required. There may still be a greater difference between us and them; for there is a sort of Animals in the World, as Oysters, Lobsters, and Crab-fish, whose Flesh is on the inside of their Bones as ’twere. What if the Planetarians should be such? O no, some body will say, it would be a hideous sight, so ugly, that Nature has not made any but her refuse and meaner Creatures of such an odd Composition. As for that, I should not be at all moved with their ugly shape, if it were not, that hereby they would be deprived of that quick easy motion of their Hands and Fingers, which is so useful and necessary to them."

Christiaan Huygens, Koσµoθεωpoσ, "Cosmotheoros" (1698)



Edited 3 time(s). Last edit at 01/31/2015 12:10AM by anybody.

Life forms here on Earth that we see are the result of environmental conditions, niches that were available, mutations that happened at various times that altered forms, and contingency.

I think it would be highly unlikely other life forms would be like us. They may not have circulatory systems based on oxygen concentrations we have. They may not have evolved with the same gravity, sunlight, etc. Mutations and opportunity could lead the development in ways they did not here. The timing would have to be right. Contingency could have impacted the process- did they have a near extinction, a catastrophic event, etc.

It's a fascinating topic. Looking at all the stars, I would think opportunity would exist somewhere else. However, the events that shaped us would likely be different.

When I look at much of the life that evolved on earth and see how different I can be even evolving on the same planet, I think it likely that it would not be the same.

This..

I've thought about this for years. Obviously, when TV or movies depict aliens, they usually make them a bit human-like so we can relate to them. My own guess is that alien life would most likely be carbon based like ours, as that is a chemically likely scenario. Carbon is so versatile. Being bilaterally symetrical seems to be a trend that evolution followed as well. The other thing is that any intelligent and technically able life form would have some sort of dexterous "hands." They'd have eyes that could see what the hands were doing, and be able to alter their environment. This still leaves a lot of room to look different than humans, though. I think they would not have the same form. One special thing that happened to earth is that it got an oxygen rich atmosphere, allowing turbo-metabolism Among animals. This is probably a rare and fleeting condition. We are probably not the only intelligent life in the universe, but we are a rarity in both time and space. Thats why we haven't yet found ET.



Edited 1 time(s). Last edit at 01/31/2015 08:33PM by rationalist01.

No, it wouldn't have.

Evolution by natural selection is simple statistics: stuff that works (for survival and reproduction) sticks around and spreads, stuff that doesn't, doesn't.

Mutations get offered up all the time, which ones are selected is largely (though not entirely) based on the conditions the organism finds itself in -- its environment. For life on other planets to evolve just like life on earth did, the conditions would have had to have been identical...and that's *extremely* unlikely. Especially over the billions of years evolution has been operating on living things on earth.

Things that are at least likely to be similar, though...carbon-based life (for very good periodic-table reasons), use of or reliance on water, a few other things. But not even DNA as information storage is all that likely to be similar.

You mean, like tall chimps who lost most of their hair?

Dolphins are intelligent too. Why not like them?

Maybe they look like the insects from Starship Troopers.

but that didn't stop crazy Mormons from trying to set up a colony on one their planets ;o)

According to the CULT, Kolobians looks like they are from earth.. perhaps Kolobian could answer this? Kolobian?

Missed making a post on time, but just to broaden the discussion with some people's experiences from their subconscious mind...

Some(?) spiritists believe there are many planets people have reincarnated on. Some where 'intelligent life' reincarnated beings live at the bottom of the ocean. People that have dreams were they are able to breathe underwater supposedly lived on those type of planets.

Other spiritist believe there are planets where 'intelligent life' flies through the air. People that have dreams where they are able to fly supposedly lived on those type of planets. Note flying is different than going instantaneously from one location to another as the latter is an attribute of the spirit world (life between lives/heaven/with God).

Along with other planets that people can reincarnate on spiritists believe there are also different dimensions. The spirit world would be one of those other dimensions.

I got the impression/feeling/dream 'intelligent life' that can fly or live under the ocean may resemble but more likely not be that close to humans.

Just wanted to expand the discussion ------ with some thing more that just conjecture. Some spiritists claim to have experienced/drawn these things from their subconscious. As for me I recently did a guided meditation where I was directed to my 3 'latest' past lives (glimpses only) and they were definitely all on this planet (Europe (1) and US (2)).

. . .it finds itself.

That includes

--oxygen-absent conditions:

http://mmbr.asm.org/content/76/2/444.short


--and various other kinds of extreme conditions:

http://www.iflscience.com/plants-and-animals/life-extreme-environments


Given the unique factors of those environments, there's no guarantee that the lifeforms which emerge in response to the stimulant conditions in those particular settings will look anything like us.



Edited 4 time(s). Last edit at 02/02/2015 11:32PM by steve benson.