There are animals without any brains or hearts at all. Jellyfish, flatworms, etc. Pumping blood and organizing nerve impulses from a central location are nice but clearly not required for life to exist. In ours and most other cases they evolved over time because they were beneficial in some way. As I have said, those who disagree with evolution typically do so because they don’t understand it. How many time have I heard the argument that certain organs must have just popped into existence without having evolved from something simpler? It simply implies a lack of understanding.
You do know that only about 1 in 100 mutations are neutral or beneficial. “Paramecia” could and still cannot not see, hear or pump blood. Yet, you expect me to believe that there existed a step by step process whereby fish, birds, insects, cheetahs and man evolved into being. Sorry, I lack the faith necessary to become a disciple of Darwin.
Still love ya’, FRiend!!!