That is not the brave way out. You ought to give an honest try at explaining what fusion is in a few words. Your whole cases about the OP rests on that.
You cannot piggyback your fantasy past on the coat tails of actual reason and current reality.
When Noah kicked the ball, did gravity and no other balancing forces exist, and did it exist precisely at the same strength? How in the world would you know???? Let's be clear the issue is NOT how a ball behaves when you kick it here. Time to be more grown up.
Speculation. You are in essence claiming that a same state past had to exist, but perhaps with a few quirks. How in the world would you know??
When we talk of heaven, and the afterlife we would be using the spiritual in every conversation. When we talk of a different past before this world existed or the universe, we also would not be straitjacketed to present state rules alone. Likewise, when we are talking about the recorded different past, there is NO reason to limit our models and thoughts to current laws. THAT has been the fatal flaw in man's wisdom, and it is the clear mark of inspiration. Better than fingerprints. Distinctive and clear markings of direct Satanic inspiration and source.
Gen 3:
Yea, hath God said, Ye shall not eat of every tree of the garden? 2 And the woman said unto the serpent, We may eat of the fruit of the trees of the garden:
3 But of the fruit of the tree which is in the midst of the garden, God hath said, Ye shall not eat of it, neither shall ye touch it, lest ye die.
4 And the serpent said unto the woman, Ye shall not surely die:
You are refusing to show what fusion is according to you. Therefore it is you that are asking us to believe that whatever it may be, it was the same in the past. I prefer to operate more from a position of knowledge.
No problem. Show us what fusion is then, of the chromosomes in the OP. We can look at the actual forces and laws that cause it.