What a way to oversell the discovery.

The reality is:

    * Different brain regions have different functions: ancient knowledge.
    * Different regions contain distinct cell types and molecular programs: also well established.
    * Anterior and posterior brain structures may trace back to fundamentally separate progenitor lineages that were independently specified very early in evolution and development: that's the interesting new result.

The headline should have been: "Human forebrain and hindbrain arise from distinct embryonic progenitor lineages" - not that we have "two organs" in the brain.

Though I agree with the detailed differentiation, still for the headline purpose a generic one that resonates with people easily isn't a bad choice

Lying is always a bad choice. The paper in Nature says

"Hence, we postulate the brain is a composite organ emanating from two lineage-restricted progenitors; these dual progenitors may be evolutionarily conserved across 550 million years from hemichordates to mammals."

Given the parallel example cited in the article of jellyfish having two spatially separate organs, & the subsequent speculation that our own ancestors could also have had spacially separate anterior & posterior masses, the title doesn't really seem unreasonable in its hyperbole.

While it might not be perfectly accurate it's hardly misleading.

I found the title confusing, at the very least because it can be argued that the two brain hemispheres are two organs already, as they operate independently when severed from each other.

I mean, I learned a bunch of neat new stuff, so I’m excited!

> They identified two different brain progenitor cells. One, which expresses a gene called Otx2, is destined to become the forebrain and midbrain. The other, which expresses a gene called Gbx2, is committed to forming the hindbrain. They showed that these two cell populations never overlap; they are mutually exclusive from the earliest stages of development.

Very cool. Never thought the brain could have two completely different ancestors

Fun fact: the hindbrain progenitor cell is shaped like a little lizard.

and from another post on the front page right now https://news.ycombinator.com/item?id=49735541 :

"Nervous systems are typically defined as networks of neurons that communicate across synapses. But Burkhardt’s lab found something unique in ctenophores: Beneath the animal’s outer surface is a nerve net (pink mesh in this 3D reconstruction) whose neurons are connected by continuous cytoplasm — but with no synapses between them. “I don’t think any other animal has a nervous system like that,” Burkhardt said. Because ctenophores are one of the earliest branches of the animal family tree, the finding indicates that evolution may have crafted nervous systems twice: in ctenophores, and separately in jellyfish and all other animals."

Funny thing when reading that is as a human I read „crafted nervous system twice” like it would be done over a week or two.

We fail to imagine how much time takes to „craft a nervous system”.

Super scary how small are we in big scheme of things.

I think the fact that the sentence says we share the nervous system with jellyfish gives a good indication of that.

The really exciting thing in this article is that this research led them to a new technique for growing brain stem cells in vitro, which has been very difficult until now. If that isn't being oversold, it's big news. That's going to make future research into diseases like ALS a lot easier.

bioRxiv preprint July 2025 [0]

The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY 4.0 International license.

[0] https://www.biorxiv.org/content/10.1101/2025.07.02.662771v2

PDF is free to download.

Related https://www.newscientist.com/article/2589739-our-brain-evolv... https://news.ycombinator.com/item?id=49755533

We are going to have to deprecate an idiom or two. "I'm in two minds about something" now gives the wrong meaning.

Not to mention the gut brain-- That's the organ I blame for the ice cream I just ate

The best way to stop eating ice cream is to stop buying ice cream. If it's in the freezer, it'll be eaten.

I think there is a better way: The colder something is, the less sweet it will taste. if you warm-up ice cream and taste how sickeningly sweet that soup is, you won't be having so much for a while...

I went to see Michael Gazzanigga talk about hemispheric separation some years ago. Fascinating. The two hemispheres can operate separately.

I can see how one of these is the gut feelings origin, and other bodily feelings.

The title is factually incorrect and is not what the research actually found:

https://www.nature.com/articles/s41593-026-02433-7

Title: "Two parallel neural ectoderm progenitors contribute to the developing brain".

"Hence, we postulate the brain is a composite organ emanating from two lineage-restricted progenitors; these dual progenitors may be evolutionarily conserved across 550 million years from hemichordates to mammals."

A bicameral mind cool

It's cool, but the headline is really pretty misleading.

The new result seems to be that researchers have identified different progenitors for fore/midbrain vs. hindbrain and have found that they can be identified by some specific developmental gene markers. That's genuinely cool.

However, organs are not typically defined by a single tissue characterized by a progenitor that can be labeled with a single gene marker. I suppose it's fine if on a functional and anatomical level you want to split the fore/midbrain and hindbrain into two different "organs", but whether you think of the brain as 1 organ or 2, it really doesn't change much in terms of how you would think about these regions.

It isn't at all surprising that different regions of the brain have localized functions; some of the earliest evidence of this was how focal injuries (like strokes) have characteristic deficit patterns depending on brain region affected, and obviously there has been a lot of work since then further showing the organization, function and development of different brain regions.

This isn't peer reviewed, just a press release. 10 other "papers" will be published in the next 2 weeks counterfinding anything in this post.

Science moves forward yet again with a few backward steps.

Here is the peer reviewed publication in Nature Neuroscience:

https://www.nature.com/articles/s41593-026-02433-7

The peer reviewed publication is linked to from the press release. The press release's headline does somewhat overhype up the actual finding though. The actual finding is that different parts of the brain arise from different neural ectoderm progenitors, which explains why it’s so hard to get a forebrain neuron to behave like a hindbrain neuron and vice versa in the lab. The paper then postulates that this difference in progenitors resembles being two different organs evolutionarily, but this is not really the most important part of the paper.

BTW I suspect that this finding comes as completely unsurprising to biologists and the medical field generally. I'm not in either field, but even in high school biology we learned that the brain stem is behaviorally and structurally radically different from the rest of the brain, to the point where it seems almost obvious in hindsight that it's a different cell line and potentially has a different evolutionary history from the rest of the brain.

I thought the PR article did a decent job or saying just that, except maybe for the title

Yeah, agreed. It's mostly just the title that is overhyped.

no idea what you're talking about.

watson and crick's paper was not peer reviewed, neither were darwin's papers.

not sure what you think happens in peer review but it's probably overrated.

The problem right now is that there aren't enough peer reviewers.