According to the comics, Peter Parker was bitten by an irradiated spider (in the movie it was a genetically modified spider). As a result, his body changed and he developed extraordinary abilities. Unfortunately it must be said that his abilities - as they are shown in the comics and movies - wouldn´t work in reality. Although science has already dealt with this subject, a logical explanation could not be found:

Strength: Gene doping is a method by which one can use cells, genes, genetic elements, or the modulation of gene expression to increase physical performance. The problem is that the human body has limits. A spider can lift eight times its weight (depends on the spider). This means: Peter Parker could lift 592 kg (a car weighs about twice). To give Peter a new body tissue and organs, new genes are necessary. An adult human body consists only of adult stem cells, which means they can not be differentiated. Only embrionale stem cells have the property to transform into any body cell. If the body tissue is overloaded, then it tears or breaks. In the comics he can lift 15 t - 25 t.

Spider silk: If Peter Parker has spinnerets, the amount of silk is limited, regardless of whether he uses webshooters or spinnerets on his wrists. The latter would need very strong contracting muscles which do not fit the wrists.

Climbing: Peter uses microscopic hooks to climb on walls. Spiders have hundreds of thousands of tiny hairs on their feet. There is an electrostatic force between each of these hairs and the surface it touches. It is a close-range atomic attraction called the van der Waals force. This force grows from electrical attraction between nearby molecules. But spiders are small and light. They make use of an anatomical trick with which the adhesive legs can elegantly stand out from the surface again. The hooks have a special joint that they can be folded away when needed. A person weighing 74 kg could not use this power, at least not when the hooks would be too small. Spider-Man wearing gloves; how can the microscopic hooks have contact with the wall? And what about the boots?

Spider sense: Spider-Man's "spider-sense" manifests in a tingling feeling at the base of his skull, alerting him to personal danger in proportion to the severity of that danger. How does it work? Does he have a radar system in his head? Spiders don’t have ears, they can “hear” you with their leg hairs, called trichobothria, from the pressure waves created from flying insects, and others can sense tiny vibrations in the ground to help locate walking prey. Other setae branch into smaller bristles called setules, which increase the effects of two forces - “capillary adhesion”.

Are there other explanations for Spider-Man's abilities? And if so, what should be changed? Of course, one can not avoid fundamental changes, Of course, one can not avoid fundamental changes, above all, if the comic book character should at least work in the science fiction field. Here are a few changes and adaptations:

The origin of Spider Man: Peter Parker is bitten by a genetically altered spider. The spider has been bred in a secret laboratory and is genetically capable to put the cells in human embryonic state and to determine in which type of cells they should be transformed. The course of story is the same as in the movie "The Fly" (Jeff Goldblum). Peter Parker gradually turns into a big spider. He loses his hair and fingernails, his skin burst and he turns into a disgusting lump (a type of cocoon or spider egg). The spider breaks out of that lump and builds a funnel-web (in a in a ceiling corner of a large, abandoned industrial building; Peter lives in a loft). The spider captures people who enter the building, wraps and appends them to the ceiling. Also his girlfriend is captured, but only because he/it loves her. The police will be informed and there will be a fight. The woman and the victims are freed and the spider is shot and falls off the roof. A secret organization brings the spider in an underground facility to study it. Then the unthinkable happens: grows inside the spider Peter Parker approach (he is born again). The genetic program of the spider turns its body into an uterus. Peter is fully restored, his whole body, his brain, his personality and all his memories. However, some things are different. His internal organ system is changed:

• Digestive glant: food utilization
• Spinnerets at the wrists and below the buttocks (latter to rappel and wrapping of enemies and objects)
• Grappling hooks on his hands and feet (they are longer than in the movie and can retract and extend)
• A spider silk organ, a bag-like organ that produces spider silk. It is connected by a vessels system. The organ pumps the spider silk to the spinnerets. Thus there is always a perfect pressure. A strong muscle in the forearms presses the silk out of the spinnerets. There is a spider that can spit tiny webs. It´s called Spitting Spider. Scytodidae catch their prey by spitting a fluid that congeals on contact into a venomous and sticky mass. Remarkably, though it is produced in venom glands in the chelicerae, the fluid contains both venom and spider silk in liquid form. The speed with which the silk shoots out is 8 m/s.

• Liver, spleen and gall bladder are absent and are replaced by a specialized intestine.
• A special skin that can be formed when it is necessary. It is slightly thicker than human skin and very resistant (bullets can not penetrate). The skin replaces his suit. In addition, it has the capacity to change its color: skin color and black (black might be a good camouflage in the night). With the spider silk he can lubricate a mask on his face quickly.
• Durable body tissues: The bones, ligaments, tendons and muscles are extremely strong
• Extraordinary agility: Peter can bend his limbs in all directions. This allows him a better and faster climbing and moving. In addition, he can crawl around on all fours like a spider with high speed.
• Organic light protection retina: Peter has a second retina, which falls over his eyes, when light blinds
• Unique pattern on the back: Under great mental and nervous strain or danger a pattern appears on his back:

What do you think: acceptable or nonsense?

(Sorry if my english is faulty, I´m german.)

Oh GOD. NO!

NO! NO! NO! NO! NO!

You go back to Hulk, Zardu! We are quarantining you there! BACK! BACK I SAY!

WE WILL NOT ALLOW YOU TO SPREAD ANY FURTHER! ESPECIALLY NOT TO SPIDER-MAN! GO ON! BACK!

Y'know what? If you really intend to continue down this path, take a stab at Martian Manhunter. I'd like to see what you can come up with for him. Stick to lesser known or more alien characters, and you might not receive such backlash. Stop trying to mess with super powered relatively human looking dudes.

The climbing hooks are only present in the movies. The explanation given for the ability to climb surfaces, taken from the Peter Parker Spider-Man: Back in Black tpb, reads like this:

"Spider-Man can mentally control the inter-atomic attraction between molecular boundary layers. The ability to affect the attraction between surfaces is limited to his body and another object with an upper limit of several tons per finger. This attraction has been concentrated in his palms and soles; however, since his rebirth, this attraction is enhanced throughout the rest of his body."

While this description is from when he had his Other powers, the nature of the ability wasn't changed by them, only enhanced. The reason it works through his clothes is the same as why Superman's costume isn't torn apart by bullets. I.e. the ability extends out just enough to include a thin-ish layer of clothing.

@jonsmith: I prefer objective arguments.

He can't possibly do more damage than Slott...

I AM (relatively) objective. I said 'especially' Spider-man, because while science was originally the source of his powers, over the years there have been magic connections made to his powers. Like his Spider-sense has been explained as a small connection to the 'Web of Life', the web that connects the lives of all creatures. And the explanation for why he runs up against so many animal themed adversaries (Rhino, Kraven, Vulture, Doc Ock, Lizard, Vermin, Scorpion, etc.) was because he's a 'totem' of the spider, so false totems like them seek him out. While it's REALLY unclear how much of it is legit, trying to apply science to anything even tangentially connected to magic is a Sisyphean task. You're better served going after things that are very solidly rooted in science fiction.

And as long as you're going after popular characters, trying to alter the characters to make them this different in the service of making them realistic kind of sucks the fun out of 'em, and you're going to get a ton of backlash as a result.

Hence why I said to stick to lesser known or more alien characters, like Martian Manhunter. Look him up and see what you can make of him. Since he's a very alien looking alien, and a shapeshifter at that, you might not raise as much ire as with Hulk and Spider-man.

Magic gets boring. The more scientific and logical superheroes can be explained, the more interesting they are. Look at Superman: from the beginning they have used scientific explanations for his powers, just as Spider-Man, Iron Man and many others. If everything is always explained only with magic, then the whole thing drifts off into fantasy. But Spider-Man is not The Lord of the Rings. Comic character are constantly changed. When I hear the word Spider-Man, I think of a person who is partially fused with a spider and not of a high school nerd with a red-blue costume who swings through New York. Sometime every cliché is worn.

I´m not interesting in alien characters.

Thats what people said about Joe Quesada...