New preprint up! We sequenced hundreds of samples from across one of Earth's oldest living organisms - the Pando aspen clone - to understand how mutations accumulate and spread in long-lived clonal organisms. Our results were…surprising. 1/30 This work represents a massive collaboration, led by @PineauRozenn and @ZachGompert, with crucial help from Karen Mock, Jesse Morris, Vachel Kraklow, Andrea Brunelle, and Aurore Pageot. This team brings together expertise in evolution, genomics, botany, and paleoecology. 2/30

New preprint up, showing how snowflake yeast overcome one of the greatest limitations on the evolution of multicellularity: diffusion. They do so by leveraging emergent biophysics to rapidly flow media through their bodies, like a sea sponge. 1/28 This work is the result of a great collaboration with @stpalli and PhD student @nishantnaraya15, who realized something funny was going on in 2022 when @ozan_g_b sent them MuLTEE strains to study size-based metabolic scaling laws (spoiler…there weren’t any!). 2/28

1/42 New preprint: turns out MuLTEE is not only the longest running multicellularity evolution experiment (1000 days and counting), but also the longest running polyploidy evolution experiment! It reveals how whole-genome duplication (WGD) arises and impacts long-term evolution. 2/42 You can check out the preprint here:

Or just read this detailed thread.biorxiv.org/content/10.110…

Hey, we have a new paper out proposing a new hypothesis to explain why bacteria and archaea have never evolved "complex" multicellularity.

pnas.org/doi/10.1073/pn… For a full discussion of the paper (improved nicely by the peer review process), please go to this thread on the preprint here.

https://x.com/wc_ratcliff/status/1724491350756724965?s=20

We have a new preprint up. This one is a hypothesis paper, addressing one of the bigger unanswered questions that people have been asking me for the last 15 years: why has complex multicellularity only evolved in eukaryotes, never in prokaryotes? 1/33

biorxiv.org/content/10.110… “Complex multicellularity” is a term of art, but people use it to mean large organisms with many cell types: animals, plants, red algae, brown algae and fungi. No prokaryotes have evolved complex MC, despite the fact bacteria have been MC for a long time (> 3 GYA in cyanos). 2/33

I’m delighted that our paper on the Multicellularity Long Term Evolution Experiment (MuLTEE) has, at long last, been published. This paper establishes the foundations of what I’d like to work on for the rest of my career. 1/25

Free, full access link: rdcu.be/dbPA9 In short, we’ve established an open-ended LTEE exploring the evolution of multicellularity. Over 600 rounds of selection, we observe the evolution of macroscopic multicellular groups, which are 10,000x tougher as a material than their ancestor. 2/25

OK,so I realized today I needed to correct for background brightness. Did that, plus have 2 more days of data. And what do you know, this looks reasonably linear.

Methods: All done with Roche "Pilot" tests. Pics taken haphazardly in my kitchen with an old iPhone. Not scientific Despite the definitively post hoc and crude approach, I'm reassured. That tick up at day 11 wasn't the herald of a rebound...it was just an outlier. Maybe I got more gunk from my nose on the swab that day. Or maybe it was the work of the minions advent calendar used as a backdrop

I am teaching a 5-class piece of a course entitled "Frontiers in Molecular and Cellular Biology". It's a reading course for new grad students.

My section will be about mutualism and major evolutionary transitions. But you know, MCB flavored.

Here are the 5 papers I chose. 1. @pgodfreysmith's "Darwinian Individuals".

Yep, I'm leading off my MCB paper reading list with a decade-old philosophy paper. But biological details are meaningless without a conceptual framework, and PGS's paper is crisp and accessible.

petergodfreysmith.com/wp-content/upl…

Just submitted one of my favorite papers. If you’re interested in learning about how a small difference in the life cycle of early multicellular organisms can have massive implications for the long-term evolution of multicellular complexity, read on. 1/37
biorxiv.org/content/10.110… This work is led by the incomparable @jt_pentz, in collaboration with @KAMacGillivra, @JGA_DuBose, @peterlconlin, former undergrad Emma Reinhardt, and @SFI_elibby. 2/37

The longer I've been a professor, the more I feel like grades are bullshit.

I just want students to engage with the material, apply themselves, think hard, and collaborate. I am infinitely happier when they make unique connections than check a box, but grading favors the latter Grades might make more sense for for technical certifications (showing someone has x, y, z skills), but are maladptive for deeper learning. It changes how we teach, and how our students learn. We are all trained to focus most on the least important part of the whole process.

One of the sustained rays of light over the last two years has been editing a book on the evolution of multicellularity with @peterlconlin and @xprinceps. Our goal with here is to provide a broad overview of the topic- a one stop shop for those entering the field. 1/32 I’m happy to say that our book, “The Evolution of Multicellularity”, is now officially available for preorder (shipping this spring) here: routledge.com/The-Evolution-…. The preorder is 20% off, too. 2/32

Well, this has been a long-awaited day- the first paper on our multicellularity Long Term Evolution Experiment (LTEE) is on the BioRxiv. Ever wonder how simple multicellular organisms evolve to become larger and more complex over thousands of gens? 1/35

biorxiv.org/content/10.110… TLDR: Over 3,000 generations, snowflake yeast evolved macroscopic size, increasing from ~100 to ~450,000 cells / group. This required sustained biophysical adaptation: individual snowflake yeast went from being weaker than gelatin to as strong and tough as wood. 2/35

I just got tenure, and dropping the 'don't rock the boat' mentality has taken some getting used to. Anyway, I got an email from a textbook salesperson today, and told them why I don't use textbooks in my classes. This is a classic collective action problem, but if more of us demand industry reform before buying textbooks, I think we could have an impact!