Chase Brownstein

16/16 Finally, thanks to @lifesciencestudios.bsky.social for the watercolors! I want to say finally that this type of interdisciplinary work is not possible at all without federal funding. Please #standupforscience

15/16 Thanks, as always, to my coauthors, including co-first author Maxime Policarpo, my advisor @tjnear.bsky.social and Richard Harrington, Eva Hoffman, Maya Stokes, and Didier Casane! Thanks as well to the Yale Peabody Museum, Yale EEB and TPG TPG for support!

14/16 The ages of the cave-related vision gene loss logically postdate the caves, so the ages we get are the minimum ages of the subterranean ecosystems! This suggests that some of these cave systems are up to 15 million years old! These systems have been here since the Miocene!

13/16 But we can go further! What about the caves themselves? The ages of eastern North America's iconic karst caves, such as Mammoth Cave, are actually really hard to date using conventional methods. Cavefishes fill the gap! (Photo: NPS)

12/16 Well, most anyways. Some, like species in the genera Amblyopsis and Typhlichthys, actually have pseudogene ages that predate their divergence from other species in each genus! Thus, these genomic markers of cave adaptation came before-these fishes speciated underground!

11/16 As it turns out, the ages we get from examining this pseudogene clock are younger than the divergence times of cavefish lineages from one another! So, they experienced cave-associated degenerative evolution AFTER diverging from other fishes, and thus independently!

10/16 To get to the bottom of this, we used a trick. By estimating generation times since a gene was pseudogenized, and then multiplying that by years per generation, we can estimate how many millions of years ago a cavefish, well, became a cavefish!

9/16 The problem is that, for single species diverging from a surface-dwelling ancestor, cave colonization and adaptation could have happened anywhere along the branch on the tree leading to the living cave dweller. This is because its closest surface relatives might be extinct!

8/16 We noticed that the number of pseudogenes might be associated with the age of cave lineages themselves. For example, Troglichthys rosae, the first obligate cave-dweller to diverge, pseudogenized 25 vision and light related genes ancestrally!

7/16 What's more, no loss of function mutations appear ancestral to lineages including multiple obligate cave-dwelling amblyopsid genera, nor are none present in Forbesichthys! This indicates independent cave colonization and subsequent gene function loss. But there's more!

6/16 Different sets of vision-related genes, including several involved in human disease, lost functionality in different lineages of obligate cave-dwelling amblyopsids! Not only that, but the loss of function mutations themselves are not identical among lineages!

5/16 Although the similarities of obligate cave-dwelling amblyopsids are not just skin deep (they have all elongated their skulls and bodies, deossified their circumorbital series, and reduced or lost pelvic fins), comparisons of their genomes show these fishes are convergent!

4/16 A clue is that eyed, pigmented species in Forbesichthys are deeply nested within blind, obligate cave dwelling amblyopsids, suggesting multiple origins. By using genomes, personal examination of key fossils, and CT scans, we built the most comprehensive tree yet to do so!

3/16 Most amblyopsids have degenerated their eyes and lost external pigment to become obligate cave-dwellers. Yet, the different ways in which the eyes of different species have degenerated has led to a 125-year debate about how many times these fishes invaded caves! (Photo: NPS)

2/16 Amblyopsids are one of North America's most obscure and most interesting vertebrate lineages. Endemic to eastern North America, they are part of a species-poor lineage that also includes pirate and trout perches and originated 80 million years ago!

1/16 🚨🚨 New paper!! I am thrilled to share our study that uses fossils, genomes, and a bit of geology to investigate how many times cavefishes evolved, and how they can help us figure out the ages of caves themselves! Link: academic.oup.com/mbe/advance-...

Checking genbank for an obscure clade

Pulling up to #Evol2025

Anytime a fish has stripes or spots, they all have to be painted on at the end, after I’ve nearly completed the painting. It always makes me nervous!

This is Percina caprodes, the common logperch.

#teamfish #sciart

A large proportion of these canceled awards are focused on broadening the participation of underrepresented groups in STEM, which NSF was mandated to do by Congress. At what point does Congress plan to act to restore the balance of power?

Connecticut has long been a cash cow for the federal government. But now the federal administration is threatening to withhold funds we are legally entitled to - in defiance of court orders.

If they do, we should return the favor and stop collecting money for the feds.

Phylogenomic and Population Genomic Analyses of Ultraconserved Elements Reveal Deep Coalescence and Introgression Shaped Diversification Patterns in Lamprologine Cichlids of the Congo River Abstract. Understanding the drivers of diversification is a central goal in evolutionary biology but can be challenging when lineages radiate quickly and/o

Awesome new paper from @prosanta.bsky.social, Melanie Stiassny, et al!
academic.oup.com/sysbio/advance-article/doi/10.1093/sysbio/syaf032/8129685?login=true

Immigration policy in my two countries, 2025:

🇺🇸No longer give me your tired, your poor, your huddled masses yearning to breathe free, only white people who didn’t like that apartheid ended

🇬🇧Stay away all of you squalid strangers

Even the Trojans weren't stupid enough to get IN the horse.

It’s sobering to reflect on the words of Anne Frank from 1943 and recognize the haunting similarities to some of the challenges we face in society today. She wrote: “Terrible things are happening outside. Poor helpless people are being dragged out of their homes. Families are torn apart. Men, women, and children are separated. Children come home from school to find that their parents have disappeared.” – Diary of Anne Frank, January 13, 1943 These words, though written during one of the darkest chapters in human history, echo eerily in our modern world. Stories of displacement, family separations, and the marginalization of the vulnerable persist, reminding us of the importance of empathy, advocacy, and action in the face of injustice. Anne Frank’s diary serves as a timeless reminder of the consequences of indifference and the necessity of standing up for humanity. It calls on us to reflect on how we treat one another and to ensure that history does not repeat itself. It is our responsibility to build a society rooted in compassion, understanding, and unity.

Diary of Anne Frank, January 13, 1943

These words, though written during one of the darkest chapters in human history, echo eerily in our modern world.

💔A timeless reminder of the consequences of indifference and the necessity of standing up for humanity.

So weird that they're just letting everything fall into the sea - the NHS, universities, people with disabilities, civil rights. They've locked in their own failure. There absolutely was coming back from 2010, 16, 19. Then they got elected and nailed shut their own coffin from the inside.

I am outraged by the unjust arrest of Newark Mayor Ras Baraka earlier this afternoon outside of Delaney Hall in Newark.

I am calling for his immediate release by federal law enforcement.

Antisemitism crisis on campus? 85% of political scientists say no. Plus, a rich new weekly roundup of scholarship on the Middle East. As regular readers know, Shibley Telhami and I have for several years been tracking the views of Middle East academic experts about ...

85% of political scientists say antisemitism not a major problem in their campus - in line with the results of our MESB survey - and over 90% see pressure on universities over it as a threat to democracy

abuaardvarkghost.ghost.io/antisemitism...

Thank you for spotlighting our work!!