Jonathan Lambert

Phil and his colleagues argue no. Those researchers think that Luca was actually part of a complex ecosystem of microbes that have since gone extinct. They don't have evidence for this since any traces of those lineages are long gone, but essentially they argue that something as complicated as their version of Luca couldn't have evolved in isolation.

Phil and his colleagues argue no. Those researchers think that Luca was actually part of a complex ecosystem of microbes that have since gone extinct. They don't have evidence for this since any traces of those lineages are long gone, but essentially they argue that something as complicated as their version of Luca couldn't have evolved in isolation.

Yeah, it's really hard. And so they turned to genes. So all genes mutate over time. And the tick, tick, tick of those mutations can serve kind of like a molecular clock. And the researchers calibrated their clock with fossils.

Yeah, it's really hard. And so they turned to genes. So all genes mutate over time. And the tick, tick, tick of those mutations can serve kind of like a molecular clock. And the researchers calibrated their clock with fossils.

Yeah, it's really hard. And so they turned to genes. So all genes mutate over time. And the tick, tick, tick of those mutations can serve kind of like a molecular clock. And the researchers calibrated their clock with fossils.

Right, right. And so then they estimated when Luca lived by looking at all the genetic differences that its descendants racked up. And their clock put Luca living about 4.2 billion years ago.

Right, right. And so then they estimated when Luca lived by looking at all the genetic differences that its descendants racked up. And their clock put Luca living about 4.2 billion years ago.

Right, right. And so then they estimated when Luca lived by looking at all the genetic differences that its descendants racked up. And their clock put Luca living about 4.2 billion years ago.

It was really rough. So about four and a half billion years ago, a Mars-sized planet collided with Earth to form the moon. And scientists think it likely would have taken like one or 200 million years after that for the planet to settle down enough to support life. Hmm. And in the years following, scientists think the Earth was getting continually bombarded with asteroids.

It was really rough. So about four and a half billion years ago, a Mars-sized planet collided with Earth to form the moon. And scientists think it likely would have taken like one or 200 million years after that for the planet to settle down enough to support life. Hmm. And in the years following, scientists think the Earth was getting continually bombarded with asteroids.

It was really rough. So about four and a half billion years ago, a Mars-sized planet collided with Earth to form the moon. And scientists think it likely would have taken like one or 200 million years after that for the planet to settle down enough to support life. Hmm. And in the years following, scientists think the Earth was getting continually bombarded with asteroids.

So in general, this period was once thought probably like too harsh for life to emerge.

So in general, this period was once thought probably like too harsh for life to emerge.

So in general, this period was once thought probably like too harsh for life to emerge.

Yeah, it really isn't. And that makes some researchers skeptical that this dating was accurate.

Yeah, it really isn't. And that makes some researchers skeptical that this dating was accurate.

Yeah, it really isn't. And that makes some researchers skeptical that this dating was accurate.

Right, right, right. But other researchers think that it makes a lot of sense. And if it's true, it has some pretty profound implications.

Right, right, right. But other researchers think that it makes a lot of sense. And if it's true, it has some pretty profound implications.

Right, right, right. But other researchers think that it makes a lot of sense. And if it's true, it has some pretty profound implications.