Here's the critical reason Bill Nye the Science Guy changed his mind on GMOs

Bill Nye used to think genetically modified organisms weren't a great idea.

His concern, as he outlined in a chapter of his 2014 book, "Undeniable: Evolution and the Science of Creation," was that scientists didn't have a clear picture of what they could do to the ecosystem.

But starting in February, his tune began to change. Late that month, Nye visited Monsanto, a corporation known for genetically modifying agricultural products. Around that time, Nye told Real Time's Miles Leicher that he had "revised [his] outlook."

Nye stepped in for his friend and radio host Neil deGrasse Tyson on this week's edition of StarTalk Radio to discuss his changed views on GMOs. He explained that what changed his mind was a fateful visit to the lab where scientists do the actual gene modification. There, he watched them scan the entire genetic sequence of the crops they wanted to modify.

The process, he saw, was startingly precise - far more so than it had been 20 years ago:

"This is what changed my mind, is being able to do [sequence genes] 10 million times faster than they used to be able to do it … and being able to eliminate the ones not suitable for farming and susceptible to diseases and so on. We're farmers, and we want them to come out the way we want them."

Nye also saw firsthand how scientists select the genes they are going to alter in a plant. Typically, he said, it takes 10 years from the time a gene is selected to the time it makes its way into commercial planting:

"Then they plant the promising ones in super-controlled sterile greenhouses, and the ones that have suitable qualities they propagate and it takes about five years of that and then the FDA or the Department of Agriculture does another three years, sometimes five years, then they agree it's worth planting."

When a company like Monsanto has filed for USDA approval in the past and received it, the process has generally taken about 3-5 years, so Nye is spot-on.

Monsanto, the often-criticized company known for creating chemical herbicides that run the gamut from lethal Agent Orange to Roundup, is one of the main researchers of genetically modified crops in the US. Nye's connection to Monsanto has been controversial, especially since his views on GMOs appeared to flip right after his visit to their headquarters. He alluded to this in the podcast, and assured listeners that the company isn't what changed his mind.

The crux of Nye's new opinion on GMOs is this: We are a society of farmers, and for thousands of years, farmers have been doing everything in their power to get the most product from their labor. Genetically modified crops are a way to do that.

Listen to the hour-long podcast (apologies in advance for the groan-worthy jokes from co-host Chuck Nice).