Jeff Groh

Quantitative system drift https://www.biorxiv.org/content/10.1101/2025.09.17.676933v1

Please share broadly: I am looking for a postdoctoral fellow to work on a collaborative project on the temporal population genomics of invasive Capeweed (using contemporary and herbarium genomics), with ‪‪@shaky-dingo.bsky.social‬ and colleagues

tskit_arg_visualizer: interactive plotting of ancestral recombination graphs Summary: Ancestral recombination graphs (ARGs) are a complete representation of the genetic relationships between recombining lineages and are of central importance in population genetics. Recent brea...

Excited to share our new preprint for the tskit_arg_visualizer Python package! ARGs can sometimes feel like a black box, so
@yanwong.bsky.social and I have been developing a method to programmatically drawing these graphs.

🔗 arxiv.org/abs/2508.03958

1/6

Shift in NSF GRFP award by field. The color shows the field, and the proportion of grants awarded is shown by the slope and weight of the line.

Fields like Computer Science, Physics/Astronomy, and Chemistry saw the largest increases in NSF GRFP awards in 2025.

Meanwhile, Life Sciences, Social Sciences, Psychology, and Mathematical Sciences experienced the steepest declines—marking a major departure from historical funding patterns.

Looking forward to #Evol2025! I’ll be presenting on the genetics of a balanced polymorphism for sex timing in hermaphroditic plants in the Reproductive Systems session on June 22 at 11:15 AM

NSF, NASA and NIH budgets per year, inflation adjusted from 2000-2025 along with the proposed cuts. NSF includes research component only. Massive cuts across all sectors, well below support spanning 25 years.

How bad will it be? Catastrophic.

Proposed cuts to #NSF, #NIH, and #NASA will set the US R&D landscape back 25 yrs+, cause economic and job loss now, and undermine innovations to come.

But, this is the WH's *proposed* budget.

Speak up now before it is too late.

(inflation adjusted $-s below)

Congrats!!

Increased rates of hybridization in swordtail fish are associated with water pollution Biodiversity loss can occur when disturbance compromises the reproductive barriers between species, causing them to collapse into a single population through hybridization. Recent research has documen...

1/9 Excited to share the preprint for the second half of my PhD with @mollyschumer.bsky.social: Connecting human environmental impacts to hybridization in swordtail fish through genomics, GIS, water chemistry, and histology. Thread below!

#SciSky

www.biorxiv.org/content/10.1...

New Academy Members Elected in 2025

Congrats to my wonderful PhD advisor @gcbias.bsky.social on being elected to American Academy of Arts & Sciences! www.amacad.org/new-members-...

Biologist Jeff Groh wrote home to Hummelstown PA 🚜 to lay out the many costs of cuts to American science infrastructure. “Let’s not ruin a good thing” 🧪🏠

Inspired by others on here I wrote a short op-ed in support of federal research funding for a local newspaper in small town PA where I grew up

Photos: Nationwide Protests Against Trump and Musk Images from some of the hundreds of anti-Trump demonstrations across the country.

More than 1,200 demonstrations were held across the country on Saturday against the policies and actions of President Donald Trump and Elon Musk. See images from some of the protests in California, Florida, Washington, D.C., and more.

Thanks! It certainly seems that a common theme is structural DNA variation affecting allele-specific regulation of flowering genes to regulate timing. In this case, we don't find evidence that the mechanism directly involves the 3' UTR

We would love feedback on a new NCBI-BLAST service we are launching today: sky-blast.com

Under the hood it's the same BLAST executable and databases provided by NCBI, with a replica of the NIH's interface - providing an alternative to the US gov service that's less congested, faster & more reliable

updated link to their preprint www.biorxiv.org/content/10.1...

Grateful for the support from co-authors including Gracie Ackerman (UCD undergrad), PhD advisor @gcbias.bsky.social , M Wenzel of Sonoma Bot Garden, and USDA Wolfskill germplasm collection

We discuss the implications of our findings for evolution of heterodichogamy, and turnover vs stability of the genetic systems that control it.

Similar haplotype structure for heterodichogamy in both Pterocarya and Cyclocarya, and gene expression patterns of GFAFL in Cyclocarya flowers

Heterodichogamy in Cyclocarya involves a distinct pair of alleles at GFAFL with a reversed direction of dominance. The alleles are specialized in unisexual flowers and expr again implies a trans interaction. Parallel genomic structure to the Pterocarya locus suggests a similar mechanism in both

In work done independently from ours, a separate group identifies the same locus and expression patterns with complementary methods, and provides direct evidence for regulation by small RNAs. doi.org/10.1101/2025...

In Pterocarya the trait maps to a narrow region of balanced polymorphism containing a single flowering gene, GFAFL. Allele-specific GFAFL expression patterns in flowers imply existence of a trans-acting mechanism which we hypothesize to involve small RNA based on structure of the dominant haplotype

Pictures of two dichogamy morphs in Pterocarya trees, a graph visualizing flower dimorphism, and a phylogeny of the Juglandaceae family showing divergence times and origins of genetic systems for heterodichogamy.

I'm excited to share our new preprint on the molecular evolution of heterodichogamy in two wingnut genera of Juglandaceae. Heterodichogamy features two morphs synchronously alternating male and female flowering phases in time to generate disassortative mating.
doi.org/10.1101/2025...

Allelic turnover and dominance reversal at a single-gene balanced polymorphism controlling heterodichogamous flowering in wingnuts (Juglandaceae) https://www.biorxiv.org/content/10.1101/2025.03.10.642504v1

Stand up for science flyer, happening on March 7th in DC & nationwide with more information at www.standupforscience2025.org

WHERE WILL YOU BE TOMORROW?

Evolutionary lability of a key innovation spurs rapid diversification - Nature A study shows that the rapid diversification of cichlids in African lakes is driven by their ability to evolve between having simple or complex teeth.

1/10 *** New paper out *** (on behalf of Nick Peoples who is not on Bluesky). I am beyond excited to present our new paper out now in @Nature! Here, we show that rapid gain and loss of tooth complexity accelerates diversification in fishes! www.nature.com/articles/s41...

Horticulturalists, Biologists, Engineers: Federal ‘Bloat’ or Valued Experts? President Trump’s effort to remake the government is a direct challenge to a decades-long effort to build a civil service stocked with experts. Critics say it will backfire.

This one hits close to home. Rachel was one of the collections managers for a nat'l germplasm repository in Winters, CA where I've done a lot of my research. Invaluable resource that that will take a big hit from this www.nytimes.com/2025/03/02/u...

🤯

I usually reserve this account for my personal views; but today I want to represent my position as President of @asn-amnat.bsky.social to post a message that will shortly go out to the membership of the American Society of Naturalists from the ASN Executive Council

same! 2 weeks after yours :0

Here's a couple I used

Postdoc jobs in the Gaut lab! Brandon isn't on here, so I can be frank: he is fantastic. I did my postdoc with him and he is not only an amazing scientist but one of my favorite humans. I would have happily stayed in his lab forever if that was feasible. recruit.ap.uci.edu/JPF08999 #plantscijobs