Hello everyone and welcome to the Mindscape Podcast. I'm your host, Sean Carroll.

N equals 1. That's fighting words in scientific circles, where N means the number of data points you have,

and 1 is the smallest number of data points you can have that is more than zero.

When you're looking for trends or features of scientific systems and you only have one data point,

it's tempting to say things of sweeping generality, but it's very hard to know that you're on the right track.

Sadly, there's a famous case where we're stuck in some sense with N equals 1, which is the origin of life here on Earth.

Not only do we only have one example of life in the universe, namely life here on Earth,

but as far as we know, life only began once, or if it began multiple times,

the evidence has been wiped out of everything else.

So what can we do about this if we want to understand things like what is the likelihood of life elsewhere?

And if it is out there, how do we go looking for it?

So today's guest, Betul Kachar, is an astrobiologist and synthetic biologist,

who studies paleogenomics.

So I think that's how you pronounce it.

I never know how many syllables are in these biology words, but the idea is to learn about early life,

not just by looking at fossils, because many fossils that we would like to have just don't exist,

or all the interesting information has been wiped out,

but to look at current life, to compare the genomes and the proteins and other things going on

in different contemporary organisms, and learn about their commonalities, look in detail at their

family trees, right? That's the phylo in phylogenomics, and try to reconstruct what it was like in the past.

What are the structures that we all share?

And the great news is that this kind of approach moves us from N equals 1 to N equals quite a few,

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