Why? You think there can't be something missing from the DNA that affects cell replication and repair or some other mechanism that would keep the body free from death? Scripture says there is "another law" at work in our bodies, a law God did not put there, a law we inherited from Adam down the male line, hence the virgin birth. It's why babies die even before they have committed any personal sin of their own.
Romans 7:23
But I see
another law in my members, warring against the law of my mind, and bringing me into captivity to the law of sin which is in my members.
Are you one of those who thinks the God, who "takes no pleasure in death", formed a body for Adam that would die apart from sin? That after giving him strict instructions of how death would result from disobedience that Adam would have died anyway regardless, obey, disobey, it's all irrelevant?
Science only has the flawed, corrupted body to work with in order to work out what is or is not happening and there is no way to obtain a body that is perfect as Christ's was or Adam's before the fall.
You fail to recognise what the physical perfection of animals represented and was meant to teach the Jews regarding the perfect sacrifice. If all God needed was a perfect physical specimen, then any man of such a physique could qualify. It was the perfect
spiritual candidate that was required, the only man without sin, who could qualify to be our substitute.
The only "inconvenient facts" I tend to witness in your posts is your ability to completely miss the spiritual meaning behind God's working.