jeffspear.bsky.social
@jeffspear.bsky.social
Postdoctoral scholar, University of Chicago, Tsegai lab | I study mammalian locomotor evolution | I approach my research using integration, biomechanics, and phylogenetic methods.
Pinned
A tool to quickly match taxon names between a dataset and a phylogenetic tree, built for folks doing phylogenetic comparative analyses: github.com/spearw/phylo...
GitHub - spearw/phylo-match
Contribute to spearw/phylo-match development by creating an account on GitHub.
github.com
This is great. It's not as in depth as the suggestions here, but at my JC in grad school we always asked two questions at the end: "What is the most valuable thing we can take from this paper?" and "What's the next step we would take related to that most valuable thing?" It was fantastic.
January 13, 2026 at 9:34 PM
A great question about the context of Sahelanthropus from @fossilhistory.bsky.social. Figured I'd share it and my best attempt at answering it, rather than letting it linger in replies.
...but it matters for how the fossils + findings are interpreted, of course.

It’s my understanding that there’s some uncertainty around the fossils’ provenance and dating.

If the dates were revised, for example, how might that change your interpretation of the evolutionary significance?
January 7, 2026 at 3:16 PM
This was one of those exciting papers to write where many of the results genuinely surprised me. I'm proud of the work we did on this one, and huge thanks to Scott for leading and to all my co-authors, as well as the reviewers for important feedback! www.science.org/doi/10.1126/...
Earliest evidence of hominin bipedalism in Sahelanthropus tchadensis
Limb bones of the earliest known hominin, Sahelanthropus, are chimpanzee-like in shape but demonstrate adaptations for bipedalism.
www.science.org
January 2, 2026 at 7:22 PM
If you want to understand the war in Ukraine, watch @anderspucknielsen.dk. For the investment of watching just a few 10-15 minute videos per month, you'll understand the war better than most journalists (and far better than the US administration lol).https://www.youtube.com/watch?v=BiTNUZ2zONY
Europe's great power move: EU secures Ukraine funding
YouTube video by Anders Puck Nielsen
www.youtube.com
December 20, 2025 at 4:37 PM
Reposted
Professional anatomist here. I label this diagram "Job Security."
Given all the recent buzz about how great ChatGPT has gotten, including its prowess with images, I figured I'd check in on its anatomical skills. Nope.
December 19, 2025 at 4:08 PM
This kind of simple, robust, hypothesis-driven test of our existing assumptions is so important for our ability to interpret fossils. We need more of it!
Congrats to our coauthor Joseph Won (PhD Program in Anthropology, CUNY Graduate Center) on his 1st publication.
Curvature of the hand & foot proximal phalanges varies between two orangutan species consistent with differences in their substrate use (all trees vs. some ground use). 🧪
Pedal and Manual Proximal Phalangeal Curvatures Among Pongo abelii and Pongo pygmaeus
Objectives Phalangeal curvature in hominoids correlates with locomotor behavior, with greater curvature associated with arboreality. Prior research using 2D geometric morphometrics (2DGM) demonstrat...
onlinelibrary.wiley.com
December 1, 2025 at 9:41 PM
Reposted
This Thanksgiving, I’m thankful for people who put their data on Morphosource.
November 29, 2025 at 2:49 PM
Reposted
Paleo folks: Please recommend researchers (incl yourselves) interested in phylogenetic reconstruction in deep time, molecular clocks (discord w/ fossil clocks), foundational/methodological issues in phylo/paleo-reconstruction & who'd be interested in hanging w/ historians & philosophers of science ⚒️
November 24, 2025 at 12:02 AM
Angela Collier is fantastic, and this is possibly my favorite of her videos. Highly recommend a watch for a fascinating story about the discovery in insulin and who gets the credit.
who gets the Nobel prize?
watch me weep openly about the discovery of insulin.
who gets the Nobel prize?
YouTube video by Angela Collier
youtu.be
October 11, 2025 at 1:50 AM
Curious whether anyone knows if authors of scientific papers are members of this Class, or whether we signed that away to the publishers? Regardless, it's interesting to see which of my papers were used.
Just a reminder to check for your name in this list of books that OpenAI trained from. If your name is there, they probably owe you several thousand dollars.

OpenAI cried that if everyone eligible author files, the company will go bankrupt, so I'm alerting every author I have ever spoken to.
Search LibGen, the Pirated-Books Database That Meta Used to Train AI
Millions of books and scientific papers are captured in the collection’s current iteration.
www.theatlantic.com
September 7, 2025 at 2:01 AM
First official postdoc paper out in @jexpbiol.bsky.social! We compare different approaches to studying kinematics in a macaque ankle and note that the talocrural joint seems to contribute minimally to dorsiflexion of the foot during stance phase. journals.biologists.com/jeb/article/...
Comparison of ankle dorsiflexion using XROMM and external angular kinematics in a quadrupedally walking macaque
Summary: Different approaches to measuring ankle dorsiflexion capture different underlying kinematics. Evidence indicates that dorsiflexion at the talocrural joint is actively limited during walking i...
journals.biologists.com
September 4, 2025 at 1:12 PM
Reposted
Buried in the regime's political takeover letter of the Smithsonian is the worst bit. Unlike exhibits, which are non-destructive towards primary materials, temporary in nature, and reversible, the foundational collections are irreplacable. They want to be able to throw stuff out.
August 13, 2025 at 1:59 AM
Reposted
I am no constitutional scholar, but I can't help but feel that "the President gets to dictate what every university can teach and what every television station should broadcast" is closer to what the founding fathers were worried about when it comes to free speech than trigger warnings on syllabi.
July 23, 2025 at 4:27 PM
Reposted
One of the marvelous things about the United States - something it shares with Rome, I might add - is that American identity is fundamentally legal in definition and almost totally binary.

Regardless of my politics or his, Zohran Mamdani, naturalized in 2018, is every bit as much an American as me.
June 25, 2025 at 11:34 PM
Using ancestral state reconstructions to generate hypotheses about primate evolution and testing them against the fossil record. urldefense.proofpoint.com/v2/url?u=htt...
This has been in the works a long time and I'm really pleased to finally have it out! Thanks to all who contributed.
Deep-time history of primate behavior and ecology as revealed by ancestral state reconstructions
urldefense.proofpoint.com
May 31, 2025 at 4:45 PM
Reposted
Musing: one side effect of constantly defending (eg an institution or a political party) against disinformation and bad faith criticism is that you can become habituated to ignoring all criticism (as bad faith), which makes it difficult to learn, adapt, grow, and address your actual weaknesses.
May 21, 2025 at 3:18 PM
Reposted
Population wide supplementation as a public health intervention is not new and has yielded incredible health benefits through the years don't let the misguided attacks on fluoridated water fool you.
Why do you think iodide is added to table salt? Since we are intent of forgetting history here is a 🧵
May 15, 2025 at 7:55 PM
Reposted
“And I’m like, what do you mean, you ‘do your own research’? You running a double-blind study in your living room, dawg?”
- A guy walking ahead of me with his friends on a NYC sidewalk in 2021, also my favorite overheard dialogue of the entire pandemic
April 30, 2025 at 11:36 AM
Reposted
PhD Timeline xkcd.com/3081
April 25, 2025 at 3:32 PM
Reposted
TLDR: the administration wants to remove habitat loss from the definition of "harm" for endangered species, which will effectively gut the ESA.

I just commented. If you're in any way interested in ecology, nature, and the protection of endangered species, you should, too. Free daily action!
My friend's student asks me to share:

The administration is trying to destroy the Endangered Species Act from within. Public commenting is basically the only way to thwart this rule before getting to court. If you have a few minutes to comment:

www.regulations.gov/commenton/FW...
Regulations.gov
www.regulations.gov
April 21, 2025 at 6:20 PM
New paper on evolvability in apes, and whether it can help us make sense of the messy evolution of locomotion in that group. My results suggest a feedback effect between integration and the response to selection. We need more research on how integration evolves! link.springer.com/article/10.1...
Integration, Modularity, and Homoplasy in the Forelimbs of Apes - Evolutionary Biology
Covariation constrains and biases the evolution of morphological traits, leading to similar phenotypes appearing repeatedly in certain clades. Here, I test whether this phenomenon can explain the evol...
link.springer.com
April 20, 2025 at 4:14 PM
A tool to quickly match taxon names between a dataset and a phylogenetic tree, built for folks doing phylogenetic comparative analyses: github.com/spearw/phylo...
GitHub - spearw/phylo-match
Contribute to spearw/phylo-match development by creating an account on GitHub.
github.com
April 14, 2025 at 3:11 AM
Reposted
This is how I tend to think about our history, to be honest: the story of American greatness is a story of overcoming the flaws in our republic.

And there are periods of retreat and backlash, but in the past, we've always renewed the quest for that more perfect union.
"I don't want a Disney vacation of our history! I don't a whitewashed history, I don't want a homogenized history. Tell me the wretched truth about America, because that speaks to our greatness" -- 20 hours into his speech, Cory Booker is spitting absolute 🔥
April 1, 2025 at 11:36 PM