Theoretical biologist and advisor to data scientists at the University of Arizona. Mostly theoretical population genetics and molecular evolution, but I've also published in biochemistry, infectious disease, aging, economics, education. Opinions are my ownhttps://bsky.app/profile/joannamasel.bsky.socialhttps://bsky.app/profile/joannamasel.bsky.social/post/3ms7m5ahwps2hWe derive a working hypothesis for how the genetic code evolved, by assuming LUCA-depleted amino acids came early, using codons we infer via the 2-1-3 rule. We validate with independent data and a control ordering https://ecoevorxiv.org/repository/view/14173/ @seekingluca.bsky.social @hanonmcshea.bsky.social 1/1303 Aug 2026 23:01 +0000at://did:plc:5uvs2pasxffbzonmc5bqvoix/app.bsky.feed.post/3ms7m5ahwps2hhttps://bsky.app/profile/joannamasel.bsky.social/post/3mrnfpso3as2vOur paper on how better amino acid substitution matrices trained on cleaned alignments improve gene tree inference, and on best practice for cleaning MSAs more broadly, is now out https://academic.oup.com/mbe/advance-article/doi/10.1093/molbev/msag182/8742306. New options in both IQTree and Muscle5. @phylowheeler.bsky.social [contains quote post or other embedded content]27 Jul 2026 17:19 +0000at://did:plc:5uvs2pasxffbzonmc5bqvoix/app.bsky.feed.post/3mrnfpso3as2vhttps://bsky.app/profile/joannamasel.bsky.social/post/3mot4ehpskc2vSo the #SMBE2026 conference app seems pretty unusable. You can only star whole sessions not individual talks, and you can't see which talks are on at the same time. Before I burn CO2 feeding it to an AI agent to produce a usable spreadsheet, does anyone already have one?21 Jun 2026 19:32 +0000at://did:plc:5uvs2pasxffbzonmc5bqvoix/app.bsky.feed.post/3mot4ehpskc2vhttps://bsky.app/profile/joannamasel.bsky.social/post/3mnfa74k7xk22Our new paper https://doi.org/10.1098/rspb.2026.0600 on long-term genetic threats to small populations finds that "mutational meltdown" (bad mutations fixing) is less of a problem than "mutational drought" (too few good new mutations) @wmawass.bsky.social @uliseshmc.bsky.social @jeremyjberg.bsky.social 1/503 Jun 2026 13:38 +0000at://did:plc:5uvs2pasxffbzonmc5bqvoix/app.bsky.feed.post/3mnfa74k7xk22https://bsky.app/profile/joannamasel.bsky.social/post/3mlwjha3gh22gOur paper unpacking "fitness" is out https://doi.org/10.1093/genetics/iyag090. How to define fitness depends on what question you ask. Selection acts on organismal vital rates, longer-term outcomes make sense for genetic lineages, models link them. "Invasion fitness" = speed, but sometimes probability matters more. [contains quote post or other embedded content]15 May 2026 23:48 +0000at://did:plc:5uvs2pasxffbzonmc5bqvoix/app.bsky.feed.post/3mlwjha3gh22ghttps://bsky.app/profile/joannamasel.bsky.social/post/3mlr6gnmzrk2qWe are failing the hantavirus drill. But even this great @dwallacewells.bsky.social article doesn't discuss frequent PCR tests for those quarantining at home. High viral load would trigger strict isolation before most transmission. Testing beats quarantining in a facility. Yes, it can be done. https://www.nytimes.com/2026/05/13/opinion/hantavirus-covid-pandemic.html?unlocked_article_code=1.iFA.yyhA.FBWf8SH0gbsc&smid=url-share13 May 2026 20:48 +0000at://did:plc:5uvs2pasxffbzonmc5bqvoix/app.bsky.feed.post/3mlr6gnmzrk2qhttps://bsky.app/profile/joannamasel.bsky.social/post/3mjlbh3y4ic2kWe (with @dornhaus.bsky.social) finally wrote up our class on how to teach modeling to biologists, which ends up being a non-trivial exercise in understanding the roles that theory plays in the scientific method. We hope others will use our class, or simply enjoy the manuscript! [contains quote post or other embedded content]16 Apr 2026 01:35 +0000at://did:plc:5uvs2pasxffbzonmc5bqvoix/app.bsky.feed.post/3mjlbh3y4ic2k