The example is :
SETI scientists are trying to find a life form that resembles humans (in many ways).
What is the subject of the adverbial phrase in bracket? Is find or resembles?
As the comments suggest, we want to put modifying phrases where they belong.
So, if scientists are using a variety of techniques to discover intelligent life elsewhere in the universe:
SETI scientists are trying in many ways to find a life form that resembles humans.
If scientists want to find a creature that walks upright, has two eyes, a brain, uses language, produces live offspring, and so forth:
SETI scientists are trying to find a life form that resembles humans in many respects.
(Using the word "respects" makes it even clearer that the phrase refers to qualities or characteristics; "ways" could refer to a manner of undertaking; but the position at the end of the sentence should be enough to let the listener or reader know that it modifies "humans".)
The adverbial "in many ways" here adverbially modifies the verb "resembles". To see why, note that it answers the question "How is it supposed to resemble humans?". If it was intended to modify "try" or "find", it would be much better to use "by many ways" to preclude construing it with "resembles", but it is certainly possible if the context points towards that, since "in" can be used for indirect agents.