To be clear, I did tweak the SWAMPY origin by removing the gangsters blowing up the lab, as it was hard to modernize without basically revamping it so much it was unrecognizable anyway, but the Alan Moore material still happened after the explosion, before Alec crawled out of the Swamp in Brightest Day.
Bottom line: with Swampy, I try to keep as much as I can from the past, and only change what little I think we have better story for now. And b/c so much of the old stuff is great, the Wein and Moore, I've tried to keep a huge majority. So here's a (rough) massive cheat sheet on his status past and present to both explain our time-line, and also to serve as a primer for anyone looking to jump on board! Goes like this now (SPOILERS if you have NOT read #0 yet - stop reading! :))
1. Alec Holland was a human botanist plagued by feelings of connection to the Green. Since childhood, he'd had dreams that he was a monster made of leaves, and felt that the plant world was calling to him, protecting him, waiting for him... What Alec couldn't know was that the Green WAS calling to him, and waiting for him. Because all across the world, there are people born with varying connections to the forces of life and death on earth. The forces (which we focus on in Swampy and Animal Man) are the Red (biological life), the Green (plant life) and the Rot (the force of decay and death). People with tremendous connections to these forces are sometimes chosen to become avatars of the forces - these people are turned into protectors of the forces, defenders of them. If you have a connection to the Green, you might be transformed into a Swamp Thing. The Red, a lame Animal Man. The Rot, an avatar Death and decay.What Alec doesn't realize is that he was born with a connection to the Green that's off the charts... The Green (spoken for by a council of Swamp Things past called the Parliament of Trees) - suspected he might have been destined to become the greatest Swamp Thing of all time, a warrior king.
2. To stave off these ominous feelings, this sense of something waiting for him in the Green, Alec threw himself into developing the bio-restorative formula - a liquid that would help grow plant life in the most arid regions.
3. He had just completed the formula when his Anton Arcane, a powerful disciple of the Rot, and a 200+ year old killer of people with connections to the Red and Green, came for him, and - posing as his wife, wearing her skin - blew his lab up. In doing so, Arcane killed Alec in way which - b/c Alec's skin was burned his skin so badly - stopped him from joining the Green and becoming Swamp Thing, the protector of the Green.
4. Alec's body rotted at the bottom of the swamp and in desperation, the Parliament of Trees broke the order of things and created a Swamp Thing purely out of plant life, drawing what they could of Alec's DNA into this inhuman Swamp Thing. This is the Swamp Thing of the Wein and Moore runs. These runs happen in the 5 years b/ween the explosion that kills Alec and the events of Brightest Day.
5. Then, In Brightest Day, Alec was brought back from the dead, a human, by the forces of life. After the events of BD, he set off to start a new life, far from the Green, alone. [This is where our SWAMP THING #1 starts in the 52].
But when a powerful lord of the Rot was released in the American desert, Alec was pulled back into a war between the forces of life and death...