If there was a planet somewhere in the universe...?

Question

...with very similar traits to earth (not EXACT of course, that's not possible) .. would the organisms that evolve there look like the ones here?

How does evolution work anyways?

Answer 1

That's a bigger question than can be quickly answered here.

Evolution involves random mutations of the genetic material (the mutations are caused by cosmic rays and natural background radiation of the soil). Mutations that are better adapted to their environment survive and reproduce. Ones that aren't better suited don't.

But even if we started out the Earth exactly as we did the first time, with the exact same ratios of elements, the exact same temperature and pressure conditions and the exact same causes of mutation, we wouldn't end up with humans and birds and crocodiles and elephants.

The number of possible mutations of a gene are a lot larger (by something on the order of a trillion times) than the ones that actually occured.
So another planet that was even a little different from Earth would not have evolved the same life forms.

But form follows function, and there have been some serious studies at several universities to determine what forms life might take in somewhat different environments.
There would be mobile creatures, flying ones, and swimming ones so there would be physical similarities to Earth forms.
For example, the mechanics of walking upright (studied objectively) suggest the best form is to have the legs directly under the centre of gravity, the sensory organs at the top (to take advantage of height), and manipulative members (arms) somewhere in the middle (to reach all areas of the body).

Answer 2

If there was (and there probably is) a planet like Earth then it would be surprising if the life forms there did not resemble those of Earth.
Evolution is the constant mutation of life. This can be caused by a number of factors including cosmic radiation, ultraviolet light , background radiation from mineral deposits or just genetic drift.
The point is that most of these mutations do not help that species survive any better than its parents and will die out, BUT, every now and again one happens that does make a positive difference and the lifeforms carrying that gene will prosper and have more offspring so the gene gets passed to the species as a whole.
The creatures on the other world would have to adapt to a similar environment as us so would probably follow roughly the same lines.
One thing that we can be reasonably sure of is that the dominant species will walk erect and will have forearms adapted to fine manipulation. Its brain would be in a head that is mounted on a swiveling neck.. It will have at least two eyes and they will be situated very close to its brain.
I'll leave you to consider why it would have these features.

Answer 3

How similar? Do you mean gravity, atmosphere composition, star/sun type, distance from sun, and axis tilit are similar. If they're even just slightly off, you're looking at different chemical processes and weather, not to mention a host of other things, too.
So, no, it's unlikely that the organisms on that other planet wouldn't be similar to ours, unless you made very general comments and assessments.

Evolution is defined as "the change in the inherited traits of a population from generation to generation." Natural selection plays a role, too. As a species grows, they develop certain traits that allow them certain advantages that help specie survival. (water-proof feathers, opposable thumbs, larger brains, fur thickness, etc., etc.) Over time, the individuals in the species who are blessed with these traits live on, passing these traits on to their offspring, who in turn pass them on and so on and so on. Meanwhile, the others who didn't have the genetics to adapt as well gradually and slowly diminished or possibly developed in another way (depending on such factors as weather, prey, competition, etc., etc.)

Eventually the species' entire genetic code has been "rewritten" so that all living members of the species now carry these specific traits and characteristics.

Answer 4

I give you a star for this question. I have wondered about that many times myself. You may know that it is not just the starting conditions but several major catastrophic events which have directed out evolution. For example, if the large impact and the subsequent mass extinctions of 65 million years ago had not occurred, would humans have ever evolved? Or would mammals have been permanently relegated to a minor niche under their reptilian rulers? If there had not been a huge earthquake in eastern Africa 8 million years ago, humans probably would not have evolved.

But your question is one which has stimulated much good discussion and speculation over the years. Theories are put to the test and different schools of thought vie for academic supremacy. Thus, we learn. There is a fringe subject called exobiology. That would be the realm of such studies, all hypothetical, of course. But still, they may yield results which are interesting to consider.

Answer 5

definately yes. a good example is as follows:
earth like traits = head (of a coin)
non-earth like traits = tail (of a coin)

try flipping it say 10 times and check out how many times you get head or tail. mathematically it would be 50/50. but since current research shows more tail than head, i would put the probablity at 5 heads/95 tails. still earth-like planets are there somewhere. it exists.

Answer 6

The short answer is, no.