delur said:
Can you prove the intelligent designer doesn't exist? (i.e. the intelligent designer of the universe and the biological and physical world)
One all-powerful, benevolent entity creating the entirety of the biological world? Sure.
1. Suboptimal and dangerous anatomy; who among us
hasn't heard of a person having appendicitis surgery? How many car accidents and deaths have been caused by our blind spot, which
squid and octopi don't have?
Other animals have far fewer problems with birth than we do; the comparatively large size of our infants' heads and narrow pelvis for bipedal locomotion are a recipe for disaster. , and this can be accounted for by our bodies being suboptimal for a bipedal, highly intelligent lifestyle.
2. Parasitism; leprosy, and tuberculosis, and the Plague, and
blood-feeding fish that crawl up unsuspecting people's urethras,
worms whose sole purpose is feasting on the eye's interior and causing blindness,
ants that crack open the head of their own larvae and feast on the liquid inside, crustaceans
that eat the tongue of a fish and hook themselves in its place to steal additional food, etc.
The Tongue-Eating Isopod, which sucks blood from a fish's tongue until the structure atrophies and dies. The isopod then hooks itself into position (shown above) as a 'replacement' tongue, getting first dibs on all food the fish obtains. One of God's greatest hits? You decide!
3. Biological arms races; these include anything from immune systems and their subversion countermeasures, to sharper teeth vs. thicker hides, to more efficient systems of chasing down and tearing apart prey vs. faster legs and better evasion techniques.
This can get quite amazing at times, such as when a snake has massively toxic venom while its prey has massive resistance to venom. The curious result can be poison that quickly kills a large animal with one droplet of injection, or a mouse-sized critter that can resist doses of ordinary venom that would kill a blue whale, for example.
This, unfortunately, often has consequences outside of the immediate area. Well-adapted teeth are just as good at tearing apart human throats as that of a gazelle, for instance... so is snake and spider venom, which can have unexpected physiological effects, including mind-numbing pain, depending on which species is on the receiving end.
If there's a biological weapon, there's a countermeasure somewhere in nature. And if there's a countermeasure, there's a way to subvert it. Nature is the ultimate arms race, red in tooth and claw, not the Utopia which could be expected to exist if "The Designer" did (at least assuming "The Designer" was sane and not sociopathic). However, the state of the world remains very probable if many designers, each with competing goals and dislike for the designs of others, were responsible. Score one for polytheism and the experimental-alien-war-zone hypothesis!