question regarding evolution and other planets

If we found another habitable planet with life, then wouldn't it's evolutionary process result in completely different classes of life?

Like instead of our flying lifeform birds, another planet's flying lifefroms would be ferps.

[edit on 19-8-2007 by wildcat]

of course they would all evolve differently. animals have evolved differently even here on earth. like the difference between animals on other continents, or islands. each separate climate, natural or new predator can direct the creature to adapt and change or cease to exist. you don't need it to be on another planet but on another planet we may find an entirely different class of species classification all together. jelly like creature that gives birth to its off spring. plant life that walks and talks. who knows?

Yes I was wondering if we would ever find animals similar to those on Earth. Such as similar properties like feathers and scales.

I think finding a whole new kingdom would be unlikely.

[edit on 19-8-2007 by wildcat]

We will most likely find planets with animals that have taken a similar evolutionary
path traitwise, and we will probably be able to label them in familiar groups,
but we're not going to find Tigers and Elephants or such on other worlds.


Also, I do think we will find new classifications of life not only on Earth like planets,
heck we are still doing that to some extent even today, but especially on planets
that are different than Earth.


For instance, we might find something with multiple tentacle like appendages,
four legs and colourful feathers.

wildcat said..."Yes I was wondering if we would ever find animals similar to those on Earth. Such as similar properties like feathers and scales.

I think finding a whole new kingdom would be unlikely"



Actually I would be very surprised if we didnt find new kingdoms. You need to consider our frame of reference for life is all based on Earth lifeforms. For life elsewhere to evolve in a similar fashion as here on Earth it would have to have almost identical conditions as here. Air density, pressure, gravity, sun spectrum, chemical makeup of the atmosphere, ground, and oceans, stability of its orbit, protection from cosmic rays/ interstellar radiation and so forth. Its an awful lot of variables to expect to be repeated very often.

As for scales and feathers, all the variables I listed above contributed to their evolution as well. Scales of some sort may transfer well as a protective evolutionary development from planet to planet. Feathers may be different though, they developed under the Earths own air makeup, density and gravity. For example on a planet with a thinner atmosphere or high gravity, flying may use too much energy to be useful, or batlike wings of large membranes might be needed for enough lift. On a planet with an extremely dense atmosphere maybe jellyfish like creatures could use lighter gasses for bouyancy.

The possibilities are endless.

Unimaginable

On our planet, every nook and cranny teems with life. There are bacteria floating among the clouds; microorganisms living deep inside the earth; and entire ecosystems that have evolved around the hellish, toxin-spewing vents in the ocean floor known as black smokers. And this life comes in an astonishing -- literally unimaginable -- variety of shapes and forms. All the more astonishing when we realize that it is all based on the same type of chemical blueprint, DNA.

Now there are those who believe that Earth is unique, the only place in the universe where life exists. I don't see that. I don't see one good reason to believe that there's anything special about Earth, except of course that it's special to us.

Neither do I believe that life is rare in the rest of the universe. Observing the profligacy and ubiquity of it on our planet, I am encouraged to believe that the universe is positively lousy with the stuff.

And given the multiplicity of forms it takes on Earth alone, I don't think we can even begin to guess at the variety that's out there. Boggleplex to the power of infinity.

Walking, talking trees? Feathered tentacles? Come on, guys, take your imaginations out of the sandbox.

Imagine what a creature that lives in the methane fog of a gas giant must look like. Imagine what it takes to survive and thrive in the vacuum between the stars. Think of what an advanced civilization evolving on the surface of a ball of rock, constantly being scoured by gamma-ray blasts from neutron star collisions, might look like. Think of what might live on the satellite of a super-earth in the middle of a globular cluster, where the night sky is a single sheet of light.

Impossible, you say? Life couldn't evolve under such conditions, you say? Well, maybe you're right. But I'm betting the other way -- and going on current form, I reckon I'll win.

[edit on 21-8-2007 by Astyanax]

I take a slightly different view. Here on earth, nature has experimented with many different body forms and the more bizarre types have been tried and discarded.

Why is it that so many mammals have four legs ?

Why not eight or six legged tigers ?

Why not two legged rhinos ?

In aviation there is a saying about how form follows function. During the Cold War USA and the USSR developed several essentially similar forms with aircraft. Eventually Russian airliners ended up looking quite similar to Western ones by the break up of the soviet Union for the simple reason that after much experimentation, there was an economy of effort from developing along fairly logical lines.

I think we will find nature does the same on other planets. So long as the environment is similar and the chemistry the same, I expect evolution after a comparable period of time will roughly resemble earth's.

Just one example of what I mean:

Mini subs which have dived to deep geothermal vents on the seabed have found crabs, anemones and shrimps whose food chain is entirely based on the chemicals from these vents.

These are life forms which are entirely alien and unrelated to crabs, shrimps and anemones in shallow coastal waters, yet their forms are roughly similar . Recognisably so. These are aliens on our very own planet yet form follows function for them too.

Even their body chemistry is totally alien, yet we recognise them.

reply to post by sy.gunson


Further to that, so many creatures have 2 eyes 2 ears 1 mouth and most vertebrates have 5 digits on each limb. Would this also develop elsewhere or are these atributes only beneficial here?

It's a mystery to me how anyone can call himself an exobiologist, when life has been found nowhere else. All the principles of life on Earth, carbon-based, DNA-based are probably inapplicable in general. So what do we know?

Originally posted by VIKINGANT
reply to post by sy.gunson

 

Further to that, so many creatures have 2 eyes 2 ears 1 mouth and most vertebrates have 5 digits on each limb. Would this also develop elsewhere or are these atributes only beneficial here?

That could all be related to the great portion of DNA that we all share.

I'm not a biologist though.

None the less, I'd expect that aliens from similar planets to ours would be be similar to life here but only in a very broad sense. IE: wings, limbs, and a head. The details are all up in the air. Life on Earth has changed a lot since it first arouse.

I wouldn't say four legs is at all ideal considering many species of dinosaur did fine with only two. If the gravity was a little less and the oxygen a little thicker we might have buffalo sized beetles. So who knows...

I wouldn't say four legs is at all ideal considering many species of dinosaur did fine with only two.

Yes. but we all have 4 limbs. four legs or 2 arms/wngs and 2 legs

If the gravity was a little less and the oxygen a little thicker we might have buffalo sized beetles. So who knows...

Sounds lke an episode from Futurama (bugalos)

[edit on 29/4/2008 by VIKINGANT]