One of the benefits of human designs is that we can afford failure. If our designs don't work, they can be completely destroyed, and we can just go back to the drawing board, improving on what went wrong.
God's designs do not have this luxury. Death is permanent, and if enough individuals have a particular flaw, they soon become extinct. No respawns, no mulligans, death is permanent.
This is one of many reasons Evolution just cannot happen. Pick any organism you like, they all have certain needs and weaknesses. If these needs are not met, or these weaknesses are exposed, the organism dies. For example, how long can a fish last if it gets caught in a quickly evaporating mud pool? Answer: Not very long at all. Most fish need a lot of water. Taking them out of it for too long kills them rather quickly. And that is in just one generation. It's not like you can take them out of the water, and they won't like it, but after a few generations, the species becomes more suited to its environment. The fish die out of water. Thus, they never get to produce the next generation.
Which, let's face it, would also not be able to breathe air. See, the thing about reproduction is that it is exactly that: re-production. Organisms reproduce according to their kinds. Fish don't produce salamanders, salamanders don't produce lizards, lizards don't produce squirrels, squirrels don't produce monkeys, monkeys don't produce apes, and apes don't produce men. A fish that cannot breathe outside water will produce a fish that cannot breathe outside water.
Obviously, then, a gradual change is insufficient. If you need something now, you cannot wait for future generations to give it to you. This problem gets even bigger when you consider sexual reproduction. Sexual reproduction not only requires one organism to be fully formed, but by astonishing coincidence, also requires another, fully compatible opposite sex organism to be fully formed at the exact same time. If you have a fully formed male, it doesn't matter if there are no females, you're still not getting the next generation. If you have a fully formed female, it doesn't matter if there are no males, you're still not getting the next generation. Even if the fully formed male, or fully formed female, had all the other features they needed to live a long and healthy life, they still couldn't produce the next generation, and Evolution stops with them. Therefore, Evolution had to get sexual reproduction right instantly.
Evolution has far too many "sudden death" scenarios to overcome. Indeed, the transitional forms, which remain missing to this day, would inevitably be fatally flawed, vastly inferior to their alleged ancestors, as well as to their alleged descendants. Evolution, therefore, needs a leg to stand on, yet it cannot evolve it in this generation. So, naturally, the reasonable mind must select against it.
Thankfully for us, our God is a far greater designer than anything from the imaginations of Charles Darwin and his ilk. He didn't need billions of years to make His designs work, He knew exactly what He was doing. Thus, His designs worked, even in a sin cursed world. But therein lies the real problem: Sin. When God first created humans, the entire world was "very good". There were no thorns or thistles. There was no carnivory. No diseases. Most importantly, no death. But God gave the people two commands: Fill the earth and subdue it, and don't eat from the tree of knowledge, lest you die. Sadly, they ate, and death entered the creation.
Today, we continue this rebellion. Every single one of us sins against our Creator, storing up His wrath against us. But though He owes us punishment, all He really wants for us is life. Therefore, He sent His Son to live as a man, a perfect human life free from sin. This culminated in His public execution via crucifixion, where He received the full penalty for sin in Himself. He died, and was laid in a tomb, yet on the third day, He got up, and walked right on out. Because of this, we can be forgiven for our sin, and granted eternal life, as if we had lived like Jesus. All it requires is faith. Confess Jesus as Lord, and believe He rose from the dead, and you will be saved.