Sam Raimi's Spider-Man, starring Tobey Maguire, celebrates its 20th anniversary today. The film, which helped kick off the superhero movie craze, told the story of Peter Parker's transformation from regular high school student into the friendly neighborhood Spider-Man. While in the original comics Peter got his powers when he was bitten by a radioactive spider, the film version of Peter Parker gets his powers from a genetically modified spiders that reconfigures his DNA. When Peter awakes the next morning, his vision has been fixed, he's swole, and he has some of the abilities of spiders, including wall crawling and silk production.

Making the switch from radioactivity to genetic engineering pushed Spider-Man a little closer to reality, but how realistic is it really? Can one species transfer its DNA to another?

DNA TRANSFER THROUGH ATTACK

The only superpowers you're likely to get from a spider bite are involuntary scratching and, depending on the species, the incredible ability to shake, vomit, and swell up. None of those are very good for crime fighting.

Spiders use their bite to deliver venom from specialized glands. Those venoms are as varied as the species who use them, but they typically have similar goals. It's likely that venom in spiders initially evolved purely as a means of external digestion. The venom of some spiders still consists mostly of digestive enzymes intended to liquify a meal before a spider slurps it up like the world's most disgusting smoothie.

Other venoms are made of various neurotoxins which kill or immobilize prey, making it easier for a spider to consume them at their leisure. Most spider venoms aren't very dangerous to humans and even those which are, usually aren't fatal. At worst, they're likely to cause painful reactions or tissue death around the site of the bite. They do not, unfortunately, transmit any superpowers or modify your DNA in any way.

That said, there are organisms that have attacked you or your ancestors and left some of their DNA behind. You may have heard of them; they are called viruses.

Most of the time, when a virus shows up, it invades a cell and hijacks its machinery to start making copies of itself. As a result, you get sick and your body fights to expel the invader, often infecting other people in the process. Sometimes, a specific class of virus known as a retrovirus, gets novel DNA into our chromosomes during the process of converting its RNA.

If the cells it infects are reproductive cells — sperm or eggs — that DNA can be passed down and become a lasting part of the human genome. It's estimated that today roughly 8 percent of the total human genome was acquired in this way, and it's not all bad news. It's possible that viral DNA was responsible in part for the development of the mammalian placenta.

That's not a superpower in the strictest sense. But, also, it sort of is.

ANIMALS (BESIDES SPIDERS) WITH SPIDER DNA

While a spider bite won't transmit spider DNA into your body or the body of anything else, we have managed to make non-spider animals with some spider DNA, through the magic and wonder of science!

Pound for pound, spider silk is roughly five times stronger than steel, making it an ideal material for all kinds of things like sutures and impact resistant fabrics. The only problem is that spiders are difficult to farm. Most species don't like hanging out together and getting enough material to do something with is a challenge. So, scientists got weird with it.

Using genetic engineering, scientists have created transgenic goats and mice which produce spider silk proteins in their milk. While mouse milk hasn't yet hit the alterative milk scene — let's all pray to Crom that it never does — milking animals is something humans are pretty good at. Getting spider silk in this way is a lot more effective than getting it directly from spiders.

While the Amazing Spider-Goat would make for a fun addition to the next Spider-Verse movie, scientists have also looked a little closer on the evolutionary tree of life for the next transgenic spider animals. Most of the silk that humans harvest comes from silkworms which build their cocoons from the material. Farming silkworms results in enough material to sustain the global silk trade, but it doesn't have the same material strength as spider silk.

In order to combine the prolific nature of silkworms with the strength of spider silk, scientists at the University of Wyoming produced silkworms with spider DNA which spin hybrid silk. If production of hybrid spider silk could be appropriately scaled, it might make a good alternative for artificial ligaments. In a roundabout way, that means we might end up with spider parts in our bodies after all. Twhip thwip!