It's #NationalFossilDay here in the USA, so here's a photo of our T. rex brain endocast based on a US national fossil—AMNH 5117. The surprise was to see it on exhibit in Japan at the Fukui Prefectural Dinosaur Museum. Feel free to print one of your own: skfb.ly/Mqsq ! 🦖

Thrilled to share that I’ve successfully defended my PhD thesis on human brain evolution at @humantechnopole.bsky.social 🎓 A heartfelt thank you to everyone who has been part of this journey. Excited for what comes next!

One motivation behind this review was that recently, I learned that neurobiologists knew of Ludwig Edinger while paleontologists knew of Tilly Edinger, his daugther. It made me realized how much, we had been disconnected from one another. I hope that this review brings these fields closer again ☺️

New paper out! It was an honor to collaborate with the legend Leah Krubitzer on this review to show that paleontologists and neurobiologists working together can only improve our understanding of brain evolution 🧠 www.nature.com/articles/s44... Full access to the paper: rdcu.be/eK167

2025. From nociception in aneural animals to human suffering: toward a comparative biology of pain url: journals.biologists.com/jeb/article-...

Can Only Meat Machines be Conscious? New paper in Trends in Cognitive Sciences, free download until November 26 with this URL: authors.elsevier.com/a/1luwh4sIRv...

Homo no-lead-i. ... in seriousness, this is an interesting new paper! www.science.org/doi/10.1126/...

New online! The functional adaptations of mammalian brain structures through a behavioural ecology lens

Excited to share our new #biorxivpreprint: “Sexual dimorphism in the complete connectome of the Drosophila male central nervous system” www.biorxiv.org/content/10.1... We describe the #connectomics reconstruction and analysis of an entire adult #maleCNS #drosophila central nervous system. 1/10

Evolution of intelligence in our ancestors may have come at a cost www.newscientist.com/article/2499...

Ancient Lead Exposure Influenced the Evolution of the Human Brain bioengineer.org/ancient-lead...

Evolution may have capped human brain size to balance energy costs and survival www.psypost.org/evolution-ma...

Moreover, AGI might also require social interactions to become a reality, where cultural evolution (and extended mind) play a major role. It is not by chance that brain and culture evolved together, allowing complex minds to emerge @anilseth.bsky.social @mitibennett.bsky.social

An evolutionary perspective is much required to truly understand consciousness, how it originates and what clases we might find. We proposed a space of possible cognitions and did a comparative analysis

Can general artificial intelligence emerge by not following the evolution of complex brains? In this 2022 paper with @brigan.bsky.social we argued that embodiment, mind reading (mirror systems), mental time traveling... are necessary conditions www.mdpi.com/1099-4300/24... @anilseth.bsky.social

Thanks to Arendt group: Detlev, Leslie, Tobi, Nico @galicae.bsky.social and Phil. My amazing students @gulceserka.bsky.social, @anaverbanac.bsky.social,Maite and Dori. Huge thanks to the Kaessmann lab for all their support and fruitful discussions @kaessmannlab.bsky.social @evo-and-devo.bsky.social

We now have a unique opportunity to keep developing cartilaginous fish models. Throug their study we will be able to explore how these and other features evolved across vertebrates and uncover the molecular mechanisms driving brain evolution. Stay tuned for more discoveries and tool developments!

Our study moved the postulated origin of several developmental pallial features back to the jawed common ancestor. We hypothesize these features likely contributed to the increased complexity of their brains coincident with the emergence of predation.

Using the plasmid, we showed that the dorsal pallial area gives rise to a layered structure aligned with the positions of Reelin and CRs. Moreover, this structure corresponds with a complex anatomical region that brings together glutamatergic and GABAergic neurons, likely forming a complex circuitry

We developed a protocol to label shark neural tissue with a reporter plasmid- First time this is achieved in a Cartilaginous Fish! Impossible without (bluesky-less) Maite Boersig, Isabel Rollán, Dori Torres-Sabino and Rami Reshef. The coolest shark team ever!🦈💙

Till recently, bony fish have been the main fish reference group for comparative purpose, but contrary to cartilaginous fish, they are evolutionary speedsters, with brains that have taken unique paths.

In our lab we study the evolutionary origin of neurons and nervous systems. For this we use #choanoflagellates & #ctenophores as model organisms. Enjoy this beautiful ctenophore Mnemiopsis leidyi filmed in our facility in Bergen: www.uib.no/en/michaelsa... #evolution #origin #neuron

Another key finding of our work is that nervous systems may have became centralized EARLIER than previously assumed 🤩. We found that the ctenophore aboral organ is tightly associated with a condensed SYNCYTIAL nerve net. See below: comparison of regular vs. condensed nerve net.

The aboral organ of a 1-day-old ctenophore is composed of ca. 900 cells, encompassing 17 distinct cell types 🤩. Below are examples for each cell type. #cilia #sensory #vesicles #diversity #neuron

13. Gabi et al. 2010, Brain Behav Evol, doi:10.1159/000319872

9. Cunha et al. 2022, Front Neuroanat, doi:10.3389/fnana.2022.1048261 10. Teles et al. 2012, J Comp Physiol A, doi:10.1007/s00359-012-0721-6 11. Zupanc 1999, J Exp Biol, doi:10.1242/jeb.202.10.1435 12. Zupanc 2021, J Exp Biol, doi:10.1242/jeb.226357

5. Olkowicz et al. 2016, PNAS, doi:10.1073/pnas.1517131113 6. Kverková et al. 2022, PNAS, doi:10.1073/pnas.2121624119 7. Herculano-Houzel et al. 2011, Brain Behav Evol, doi:10.1159/000330825 8. Herculano-Houzel et al. 2015, Front Neuroanat, doi:10.3389/fnana.2015.00064

Bibliography: 1. Jerison 1973, Evolution of the Brain and Intelligence, Academic Press 2. Marhounová et al. 2019, Evolution, doi:10.1111/evo.13805 3. Herculano-Houzel et al. 2007, PNAS, doi:10.1073/pnas.0611396104 4. Herculano-Houzel et al. 2014, Front Neuroanat, doi:10.3389/fnana.2014.00077

Over generations, step changes → cohorts diverge in brain, body & neuron number. Some clades (primates, parrots, songbirds) evolve bigger brains with more neurons; others (rodents, sauropsids, mammals) grow brains faster than neurons → lower density 3-6,13. 👉 Plasticity drives brain diversity.

Across cohorts (different densities): 🐟 Larger fish → larger brains with up to 20× more neurons. Neuron density = constant or decreasing. 📐 This mirrors well-known interspecies scaling patterns, even though all fish came from the same stock.

Reaction norm model: 🌍 Environmental step changes (like density) shift whole cohorts into new scaling regimes. 🧬 Within a cohort, individual-level factors (genetics, epigenetics, microenvironment) decouple body, brain, and neuron numbers.

This pattern contradicts the “numerical matching” hypothesis, which predicts body, brain, and neuron number should always scale together 11, 12. Instead, brain size and neuron number may be regulated by different mechanisms.

Within a cohort (same density): 🐟 Larger fish → larger brains, but not more neurons. Animals with more neurons had higher neuron density instead. ⚡ This extends to fish the brain-scaling pattern seen within individuals of the same species in rodents and birds.

Across vertebrates, bigger species → bigger brains with more neurons 1-6. But within a species, this often breaks down 3,7-9. Tilapia are ideal to test: they keep growing + have adult neurogenesis 10. Researchers raised them at low vs. high density → up to 30× body size variation in same-age fish.

🚨 New in J. Comp. Neurology: "Larger Fish Have Larger Brains With More Neurons Across but Not Within Cohorts Raised in Different Growth Conditions" 🐟🧠 DOI: doi.org/10.1002/cne.... #Neuroscience #BrainEvolution #ComparativeNeurobiology #Fish #Plasticity

Here’s the first paper I contributed to: “Expression of SATB1 and SATB2 in the brain of bony fishes: what fish reveal about evolution” DOI: doi.org/10.1007/s004...

Stabilizing selection in an identified multisensory neuron in blind cavefish www.pnas.org/doi/10.1073/... "The most striking aspect, and potentially warning for the study of the evolution of neuronal cell types, is how clearly all predictions failed"

𝘏𝘰𝘮𝘰 𝘧𝘭𝘰𝘳𝘦𝘴𝘪𝘦𝘯𝘴𝘪𝘴, nicknamed "Hobbits," challenges theories about human brain evolution. These 3-foot-tall ancient relatives had small brains but were likely highly capable, crafting tools and hunting pygmy elephants.

Excited to share our recent study on human-specific features of the cerebellum and the unexpected, novel role of zona pellucida protein 2 (ZP2) in synapse development. Grateful to the Sestan lab and all our collaborators for their outstanding contributions. www.biorxiv.org/content/10.1...

Together with my other wonderful 2025 PI fellows @biologists.bsky.social @dev-journal.bsky.social, I offer a perspective about the future of my respective field. Have a read - spoiler alert: its about brain evolution and neural lineages (I know - SHOCKER). journals.biologists.com/dev/article/...

New pop sci article on the hobbits of Flores! Their wisdom teeth provide evidence that they got small by slowing growth after birth. https://theconversation.com/hobbits-of-flores-evolved-to-be-small-by-slowing-down-growth-during-childhood-new-research-on-teeth-and-brain-size-suggests-261257

Great to see this article on Kamilla's amazing work!

'Give me the head!' Neuroscientist inspires whale and dolphin research in Brazil www.npr.org/2025/02/15/n...

As the saying goes The bigger the thumb, the bigger the...um... brain Human dexterity and brains evolved hand in hand 🏺🧪 www.nature.com/articles/s42... Emphasizes role of manipulative abilities in brain evolution and reveals how neural and bodily adaptations are interconnected in primate evolution

New review on how changes in cell type composition in and outside the brain contribute to the evolution of behavior. 🧪 authors.elsevier.com/a/1lihM,LqAZ...

Paul Katz on recognizing neuronal homologues across species in the Evolution of Brain Cell Types seminar.

Our lab is 2.5 years into #ERC funding✨ Grateful for the support that enabled us to uncover the syncytial nerve net in a ctenophore - a discovery reshaping our understanding of nervous system evolution. Stay tuned for more exciting discoveries to come @erc.europa.eu www.youtube.com/watch?v=1DAE...

Let's start a conversation about brain evolution!

Maria Antonietta Tosches on Cajal-Retzius cells and the evolution of homologous cell types in the Evolution of Brain Cell Types seminar.

We invite you to connect with the TIBBE community on Mattermost, an open-source platform for real-time discussion and collaboration. This is a great space to share ideas, ask questions, and engage in conversations around the Integrative Biology of Brain Evolution. tibbe-network.github.io