For example, bilateral symmetry. I think we could expect highly evolved aliens to look similiar to life on our planet in that regard.
I tend to highly agree with this statement, but as I thought about it more I am not so sure.
My thoughts are that we do not know what we don't know. If the life evolved on a planet similar to ours I think this is very likely.
But there is the rub. We have no idea of what alien life could be like. Is bilateral symmetry a result of unique circumstances in the evolution of life on this planet?
I think there is a very high likelihood that other life out there exhibits bilateral symmetry, but am very open to the idea that we may find something that utterly astounds us and falls completely outside of any of our expectations.
To put it simply, with the knowledge we have I think you are correct. It is what we don't know that is the wild card.
Edited by Theodoric, : subtitle added
Facts don't lie or have an agenda. Facts are just facts
"God did it" is not an argument. It is an excuse for intellectual laziness.