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deadbeeves | 2 years ago
An appeal to incredulity is not an argument.
>These explanations are always full of "must have" and "must have been".
Any explanation that starts with "must have" requires that there is a single theoretical framework that could possibly apply to the world as we see it today. Since you reject this necessity, you must think there's an alternative framework that accounts for all observed phenomena (or that accounts at least as well as the theory of evolution). What is that framework?
TravisCooper|2 years ago
It IS strange, using the evolutionary framework itself, that useless mutations will hang around for thousands or millions of years (countless generations) before dropping perfectly into an extremely complex system, that itself is but a small part of a larger complex system.
Evolution teaches that small, immediately useful mutations build upon one another, reinforcing the beneficial nature of the mutation. It's impossible to build large, complex life systems (with a large number of prerequisites at each step) this way. For example, the Heart, Blood Vessels and Blood. They're each extremely complex but useless without the other two.
How would evolution slowly evolve a heart with no blood or blood vessels?
How would evolution slowly evolve blood but no blood vessels or heart?
How would evolution slowly evolve a network of blood vessels but no blood to carry or heart to pump?
deadbeeves|2 years ago
Yes. Now. Not when they first emerged.
>but useless without the other two
Unsubstantiated assertion.
>How would evolution slowly build a heart with no blood or blood vessels? How would evolution slowly build blood but no blood vessels or heart? How would evolution slowly build a network of blood vessels but no blood to carry or heart to pump?
You start with a fluid-filled body cavity where oxygen is transported by dissolution from the outside to the inside. This fluid already contains oxygen-transporting cells. Then you section off part of the cavity to enable oxygen-transporting cells to move more efficiently. At this point the OTCs are completely separated, so the fluid inside the conduits can be called blood. The animal can pump blood by squeezing its body during its normal locomotion. Eventually muscle cells are added to the circulatory system to enable oxygen circulation independently of the animal's movement, as well as to circulate it even more effectively. Later on the muscle cells become centralized as it's more efficient, not to mention that a big single muscle can pump more strongly than a distributed system of tiny muscles. Each step of the way you have a functional organism and each form performs the function of transporting oxygen more effectively.
I know you're going to say that this is a "must have" explanation, but you merely asked for an explanation. The above is a plausible series of events that could have led to the circulatory system as we see it today, so if you want to argue that the circulatory system couldn't have evolved, you'll need to argue why this explanation isn't plausible.
EDIT: Also, I can't help but notice you ignored the question I asked in my last paragraph.