lol, sorry, im not trying to be a pain or anything, the alien comparison just irks me.
The Alien answer is a viable one in the following division:
Was life on Earth caused?
>Yes
>>Was that life created by intelligent or mindless processes?
>>>Intelligent
>>>>Was that life Divine(Supernatural) or Natural?
>>>>>Divine
>>>>>>Then a God created life on Earth
>>>>>Natural
>>>>>>Then other life created life on Earth. Please start again and follow the division for that life. That life in turn might have always existed or might have been created by Abiogenesis, other Life or a God.
>>>Mindless
>>>>Then life would have developed according to some natural law. (Abiogenesis)
>No
>>Then life on Earth always was. (that would be weird and refute most of what we believe about the Earth but it is possible.)
Or the short version
Life
>Was not created
>Was created by natural processes
>Was created by a God
>Was created by earlier life (recur through the choices for that previous life)
TLDR:
The possibility that some life was created by ID by Aliens does not commit the origin of the first life to ID. However since Abiogenesis is investigating Life on Earth and not All life at this time, ID by Aliens might be true for the local lifeforms.