So, let's take the minimal case of 'complex' a system of two cells vs a system of only one cell.
Any animal from the 'other' branch that observes this 'complex' life from made of two cells and another one nearby made of only one would have the choice between two bites for the price of one and one bite.
So new 'complex' life would not be around for very long because the ohter branch has presumably already reached a higher level of evolution.
It would have be a very successful mutation to stick around long enough to have enough offspring to take on higher organisms than itself by having some survive in spite of being predated on.
The lowest level organisms best defense against extinction is their enormous numbers or symbiotic relationships by evolving in tandem with higher order forms, a brand new attempt at complexity would not have that advantage yet.
The same goes for another carbon based evolution scenario, after all, if there could be two independent complex branches of life it would not be too much of a stretch to think that over the last billions of years a second life form would have come in to existence. But it would have found each and every niche already occupied by 'our' kind of life and likely not survive long, and likely not leave any trace of its existence.
Any animal from the 'other' branch that observes this 'complex' life from made of two cells and another one nearby made of only one would have the choice between two bites for the price of one and one bite.
So new 'complex' life would not be around for very long because the ohter branch has presumably already reached a higher level of evolution.
It would have be a very successful mutation to stick around long enough to have enough offspring to take on higher organisms than itself by having some survive in spite of being predated on.
The lowest level organisms best defense against extinction is their enormous numbers or symbiotic relationships by evolving in tandem with higher order forms, a brand new attempt at complexity would not have that advantage yet.
The same goes for another carbon based evolution scenario, after all, if there could be two independent complex branches of life it would not be too much of a stretch to think that over the last billions of years a second life form would have come in to existence. But it would have found each and every niche already occupied by 'our' kind of life and likely not survive long, and likely not leave any trace of its existence.