Thinking about Origins-of-Life

Last week I was at the ISSOL 2017 conference. Unlike the huge American Chemical Society national conference, this one only had 250 attendees and no concurrent sessions. The schedule however was jam-packed with talks, posters and panels in the morning, afternoon and the evening. ISSOL is the International Society for the Study of the Origin of Life. The international conference takes place once every three years. I was at ISSOL 2011 in Montpelier, France, just as I was shifting into origins-of-life research, but I missed the 2014 meeting in Japan due to other commitments.

The conference was hosted by UCSD, home of the Sun God, a prominent art piece commissioned by the Stuart Collection. Students organize a Sun God festival every year. I could have attended back when I was a postdoc at UCSD, but I chose to skip it. The Sun God featured prominently in the ISSOL 2017 conference logo. Here’s a picture from the tote bag I received at the conference. At the opening of the conference, one of the main conference organizers explained the appropriate significance of the logo. The Sun God is perched at the coast. Interfaces of rock and water are likely environments from the origin of life on Earth. The prominent sun featured on the chest of Sun God represents the solar energy influx that drives the non-equilibrium process of life. And if you look closely at the ocean waves, you can see a succession of water droplets that could represent protocells increasing in number!

I did the usual conference things: presented my work, met new people, reconnected with people I’d met before in the field, and learned a lot of the latest development in prebiotic chemistry, molecular evolution, exoplanet hunting, and Mars missions. I took a bunch of notes on my ISSOL notepad with my ISSOL pen (also stamped with the Sun God logo) and I’ve been slowly perusing them this week back in my usual office digs. While I won’t divulge any actual scientific details (since I haven’t sought permission from other presenters), here are some of my personal highlights and observations.

1.     I had several ideas for new projects that are related to current projects. I’m excited about the new prospects and feel re-energized about research explorations. I also see some potential collaborations down the road.

2.     While there were no earth-shattering breakthroughs, there was significant headway made in addressing a number of thorny origin-of-life conundrums. In particular, the community is moving away from staking out one’s turf of genes-first, metabolism-first, or membranes-first. Rather there was a strong sense of exploring co-evolution in these areas.

3.     There was a growing recognition that “messier” experimental conditions combined with state-of-the-art analytical techniques lead to more interesting results. Thermal and hydrative cycling, pH variation and buffering, and just some clever chemistry were featured.

4.     If you’re sending a probe to another planet or moon, there is a lot of very clever technology that must be developed that is lightweight, durable, and multi-tasking. Having recently finished reading Wonderland, I see echoes of how the sense of curiosity leads to technological breakthroughs. Astro-research isn’t strictly a necessity for life on Earth, and some would argue that the money should be directed elsewhere, but it’s amazing to see the creativity in technological development that takes place.

What constraints does chemistry place on the development of biology? That’s the subject of A World From Dust, a book by Ben McFarland. The catchy subtitle How the Periodic Table Shaped Life might relate to origin-of-life chemistry, although that’s not what the book is about. I read McFarland’s book over the last couple of weeks in concert with my preparing and attending the ISSOL conference. Introducing the book, the author states his aim of exploring Stephen Jay Gould’s famous analogy that replaying the tape of life would lead to organisms vastly different from what we see today in our sample size of N=1. While he thinks that forms of the organisms may vary, chemistry and environmental factors provide strong constraints on what may emerge and the evolutionary paths ‘explored’.

The book’s content is mainly focused on the metals and their role in life, predominantly as active centers in enzymes, with vignettes related to ion-channels and nucleic acid stabilization. McFarland strongly utilizes the work of the chemist R. J. P. Williams who published a book titled The Chemistry of Evolution: The Development of our Ecosystem. I read Williams’ book some years back and it is geared more towards scientists while McFarland’s is for a more general audience. Increasing entropy via maximizing energy rate density and increasing oxygenation of the biosphere are also linchpins supporting McFarland’s narrative.

McFarland spends much of the book discussing examples of metallo-enzymes, in accordance with his background as a biochemist and professor at Seattle Pacific University. There are many examples, and I think highlighting fewer with a little more depth would have made for less choppy reading. I skimmed certain parts but I found his book much more readable than Life’s Solution by Simon Conway Morris. McFarland’s book has the same overall thrust – chemical rules constrain and therefore lead to convergence of biochemistry – while Conway Morris attempts to throw the kitchen sink at you with example after example of convergence in biology. Being a chemist, I found McFarland’s vignettes more interesting. However, missing from the book, except for occasional allusions, is the diversity of organic chemistry. Carbon, Hydrogen, Oxygen and Nitrogen (or CHON) are the main constituents of the molecules in extant life. Sulfur and Phosphorus and the metals are also important, perhaps in the processes of life and less so in terms of structural diversity. That’s a good thing to keep in mind because the ISSOL conference also featured discussion on molecular organization to effect the chemical reaction cycles of living systems, and not just focusing on building molecules of the right “structure”. Systems chemistry is important.

I’ve also been playing the new commercial version of Bios Genesis this month. I suspect thinking about the conference and origin-of-life questions was a motivating factor! I should probably post another replaying-the-tape session report with the new components. While I generally kept track of final player scores at the end of the game, I didn’t pay as much attention to tracking the early parts of the game when life first emerges. (I kept close track when playtesting to see if there were any biases due to the asymmetric powers of each player.) From what I recall, the blue (genes) and yellow (specificity) players had earlier starts at ‘creating life’ in my games this month. One might playfully refer to this genes-first or membranes-first (as opposed to metabolism-first or entropy-control-first) Of course in the game, having ‘chromosomes’ in all four colors are important for your organisms to survive so they’re all important if you don’t want your newly created organism to die off in a turn or two.

In my most recent game, parasites were excluded from the game. While I see their potential importance scientific-theoretically, and that they allow for some interesting gameplay options, I’ve found my games bogged down by parasites simply preventing life from flourishing and making it hard to get to some of the interesting later stages. I find that less fun and a bit more tedious from a gaming perspective. Certainly when introducing new players to the game, I think parasites should be left out (a suggestion I made to the designer). In the games I’ve played, parasites were essentially used in a ‘take-that’ strategy to slow down other players. Perhaps I need to think about other strategies where they can be used.

It’s been a great month for origin-of-life thinking: a conference, making good progress on one of my research projects, reading a lot, and playing Bios Genesis! I’ve ignored class prep for the upcoming semester, so this morning I started doing a little bit while the computational cluster was down for some updates.