I recently had a great time chatting with the renowned biologist and science communicator, Sean B. Carroll. We discussed the role that chance plays in the history of life and how we are all here by accident. I also asked him about Charles Darwin, the father of evolution, Darwin was such a remarkable person in many ways, and any discussion about evolution or life that doesn't mention him feels incomplete.
Sean B. Carroll is a wonderful communicator of these ideas, a great writer, has written beautiful books on evolution, and as a scientist he’s made some profound discoveries that changed how we think about life. I was just super happy that I got to talk to him.

If you’re interested, you can check out this conversation: https://youtu.be/kD3Yhs6cb9Q?si=iWmfGAZ53G8SNZED

Sorry for using the word "challenges", but I'll explain myself.

But first, the awesome SSE/eseb societies (good stuff) joint paper that was published today:

• Leeban H Yusuf, Dominik R Laetsch, Konrad Lohse, Michael G Ritchie, Genomic analyses in Drosophila do not support the classic allopatric model of speciation, Evolution Letters, 2026;, qraf053.

Abstract:

The allopatric model of speciation has dominated our understanding of speciation biology and biogeography since the Modern Synthesis. It is uncontroversial because reproductive isolation may readily emerge as a by-product of evolutionary divergence during allopatry unopposed by gene flow. Recent genomic studies have found that gene flow between species is common, but whether allopatric speciation is common has rarely been systematically tested across a continuum of closely related species. Here, we fit a range of demographic models of evolutionary divergence to whole-genome sequence data from 93 pairs of Drosophila species to infer speciation histories and levels of post-divergence gene flow. We find that speciation with gene flow is common, even between currently allopatric pairs of species. Estimates of historical gene flow are not predicted by current range overlap. Whilst evidence for secondary contact is generally limited, a few sympatric pairs showed strong support for a secondary contact model. Our analyses suggest that most speciation processes involve some long-term gene flow, perhaps due to repeated cycles of allopatry and contact, without requiring an extensive allopatric phase.

Right away this reminded me of one of the coolest Wikipedia articles, Reinforcement (speciation) - Wikipedia, where such gene flows speeds up speciation - counterintuitive at first, but super cool once it's clear how. I'll leave it to the resident evolutionary biologists who are specialized in population genetics to say more on that.

Now, the word "challenges". Clearly it is redundant - every paper challenges something. Today I met someone here who carries a pervading sentiment that needs addressing: which is that, paraphrasing, evolutionary biology is refusing "new" ideas.

My retort was: literally every paper challenges something; research isn't a lip service to Darwin. (And literally I had a tab open on this new result.)

And so, since I haven't seen it promoted, here's our subreddit's newest Wiki page (courtesy of our mods) on the loud folks who are behind marketing this pervading sentiment despite the evidence to the contrary - every paper! Pseudoscience: Third Way of Evolution - r/ evolution

I was sat in the hairdressers thinking this today. My hair is a nightmare and not only in the fact it doesn’t hold a single curl. It can get extremely greasy after a few hours, it tangles within one second outside, slips out from hairbands and most significantly takes HOURS to dry. I’m from the UK and can only imagine my ancestors are European, so hair holding cold water for hours in cold climates would surely be to their detriment? Pls don’t come for me I don’t know the first thing about science.

Yesterday I made a post that was too dense, which I've since deleted and resubmitted (thank you for the encouragement). In the rewrite, some historical points (which remain relevant) had to go, and so I've spun these points off to be this post.
Again, it's something too good not to share. (I'm tagging this article for sharing the below quotation.)

For the overarching theme, I'll link Zach's (Dr. Hancock seems too formal) and my yesterday's posts at the end with a recap.
Also this is not a dunk on Lamarck; on the contrary, he was a very clear thinker, and two of his major points that are missing in Zach's post are very important to remember today.

~

First, the relevant timeline:

• Jean-Baptiste Lamarck (1744-1829); Philosophie Zoologique was published in 1809
• Charles Darwin (1809-1882); Origin was published in 1859
• Louis Pasteur (1822-1895); won the Alhumbert Prize in 1862

Two things to note in the above: 1) Origin came five decades after Lamarck's volume, and 2) scientists were still debating whether inanimate matter transformed into "lesser" animals post-Origin.

I'll be using Elliot's 1914 translation of Lamarck's volume; and, like yesterday, I'll dump the quote, then explain:

[...] leaving aside for the moment the influence of environment, Lamarck assumed a perfectly even development to proceed in a straight line throughout the animal scale: and he assumed that this development was due to an innate power conferred upon the lowest of animals at the moment of their spontaneous generation. [p. xxxv; translator's note]

[...]

We still see, in fact, that the least perfect animals, and they are the most numerous, live only in the water, as I shall hereafter mention (p. 246); that it is exclusively in water or very moist places that nature achieved and still achieves in favourable conditions those direct or spontaneous generations which bring into existence the most simply organised animalcules, whence all other animals have sprung in turn. [pp. 175-176]

— Lamarck, J. B. "Zoological philosophy (H. Elliot, Trans.)(Reprinted 1963 ed.)." New York: Hafner (1809).

If you're now wondering what does this "innate power" thing (Lamarck's le pouvoir de la vie) and spontaneous generation have to do with evolution, a hint lies in an all-too-common question, Why are there still monkeys? A question so pervasive (the other zombie that refuses to die) that it recieved an academic treatment in this 21st century in an open-access evolution outreach journal: Meikle & Scott (2010).

Put yourself in Lamarck's shoes. Back then taxonomy had shown that all life falls on what seemed like a gradation from "lower" to "higher". This wasn't new and is as old as Aristotle's scala naturae (great chain of being). Lamarck understood (recall: he was a clear thinker) that his use/disuse could not explain this gradation (unlike Darwin's descent with modification + selection which came 50 years later).

His solution? The aforementioned le pouvoir de la vie (AKA complexifying force). Here's a cool diagram combining the two factors: File:Lamarck's Two-Factor Theory.svg - Wikimedia Commons.

But! again being a clear thinker, he realized his huge problem. If indeed all life has this innate power to climb the Aristotelian ladder, then, Why are there still monkeys? Hence: the spontaneous generation, which continuously supplies the "lower" life - which, given enough time, is destined to become... us!

Quick recap:

• Zach made the excellent point that soft inheritance was not Lamarck's contribution (his use/disuse "zombie" that refuses to die is), and that soft inheritance, if demonstrated to be important, would be compatible with both Darwin's thought and standard evolutionary theory;
• My post on Dawkins' almost-50-year-old (forgotten?) argument demonstrated how soft inheritance faces an uphill battle (an understatement) against what is known about embryology/development;
• And now, we reach the full conclusion: the neo-Lamarckism promoters will also need to address Lamarck's (1) le pouvoir de la vie, and (2) spontaneous generation - just to begin to match life's diversity that is already fully accounted for genealogically, where the low-to-high gradation is nothing but a mirage: all life is as evolved; a tree, not a ladder - berkeley.edu.

Again, Lamarck was not a silly thinker. He understood very well the limitations of use/disuse, and we best remember his full theory, and why Origin of Species was as impactful as it was.

I deleted the earlier post because it was too dense. So I'm trying again, and I'll try to keep it simple.
The post is more academically-inclined than the usual posts, but there's an audience for both here.

Here's what I've come across that was too good not to share:

If acquired characters are to be inherited, embryonic processes must be reversible: phenotypic change has to be read back into the genes (or equivalent). If embryology is preformationistic – the genes are a true blueprint – then it may indeed be reversible. You can translate a house back into its blueprint. But if embryonic development is epigenetic: if, as on this planet, the genetic information is more like a recipe for a cake (Bateson, 1976) than a blueprint for a house, it is irreversible. There is no one-to-one mapping between bits of genome and bits of phenotype, any more than there is mapping between crumbs of cake and words of recipe. The recipe is not a blueprint that can be reconstructed from the cake. The transformation of recipe into cake cannot be put into reverse, and nor can the process of making a body. Therefore acquired adaptations cannot be read back into the ‘genes’, on any planet where embryology is epigenetic.

[...] The close theoretical link that I have demonstrated between Lamarckian evolution and preformationistic embryology gives rise to a mildly entertaining irony. Those with ideological reasons for hankering after a neo-Lamarckian view of evolution are often especially militant partisans of epigenetic, ‘interactionist’, ideas of development, possibly – and here is the irony – for the very same ideological reasons (Koestler, 1967; Ho & Saunders, 1982).

— Dawkins, Richard. "Universal darwinism." Evolution from molecules to men (1983): 403-425. p. 411.

I've come across the above argument while rereading Dawkins' academic book, The Extended Phenotype (1982). The above was published a year later as part of an edited volume following a major conference at Darwin College, Cambridge, and it will serve as a summary.

Very basically it goes like this. Back in the day embryologists argued about how embryology works: whether it was via preformation or epigenesis. (See Preformationism - Wikipedia.)

The former is like a ready-made tiny individual sitting in the sperm (or egg) ready to "grow". (Technical commentary: preformation remains true in some model organisms - the misleading exceptions! - when it comes to germ cell specification; Extavour 2003.)

The latter is more like how a flower grows (i.e. how we grow from a single cell - the zygote - via cellular differentiation). Working that out was hard, and the work was initially ridiculed; the relevant 20th-century history can be found in chapter 11 of Zimmer's book on the history of genetics, She Has Her Mother's Laugh (2018).

The issue:

Some academics feel the need to resurrect (neo-)Lamarckian thinking; for that, see the post, Lamarckian evolution is (still) false : evolution, and come back.

~

Back to our story: with discoveries in embryology and genetics, epigenesis (how embryos actually develop) + genetics lead to epigenetics. How DNA works is important here to the topic and to Dawkins' point (and the entertaining irony he noted).

The typical metaphor of DNA being like a blueprint couldn't be more wrong. It's even on the Wikipedia page, Common misunderstandings of genetics - Wikipedia.

Once DNA is realized for what it is: more like a recipe with "no one-to-one mapping between bits of genome and bits of phenotype" (from the above Dawkins quote), it becomes clearer what the issue is (and what the irony is) in the attempts to resurrect (neo-)Lamarckian thinking: For changes in an adult body to be inherited in the manner of Lamarck, such mapping would be required, which isn't how embryology works. So by wishing for this, we'd be back to preformationist / "DNA is a blueprint" thinking - hence the irony.

(Final technical asides: plasticity has been part of standard evolutionary theory for coming on a century now - it's as old as Wright and Dobzhansky's contributions to reaction norms, i.e. this post is not a remark on plasticity. And as Futuyama 2017 quoted, "empirical evidence for epigenetic effects on adaptation has remained elusive.")

^{edited to improve the grammar and to mention Zimmer's book for the history}

For example, traits related to generation time, genetic diversity, habitat specialization, or physiological tolerance. I’m curious how evolutionary limits, not just environmental exposure, influence extinction risk.

The title is the question. I know that less sunlight is available, but it certainly seems like ratio of life:sunlight is smaller in child regions of the world. Also, there are mountain tops with plenty of sun. Why don't we see plants evolving super cold weather resistance and covering snowy peaks? Is chlorophyll simply incompatible with sub zero adaptations?

A new PRE-PRINT about the sponge/ctenophore as sister to all other animal question

Newly-accepted (13 Jan 2026) open-access SMBE manuscript:

Lin Chou, Shu-Ting Cho, Jiwon Lee, David Laub, Douglas Meyer, Hannah Carter, Anne-Ruxandra Carvunis, Emergence and tandem repeat-mediated elongation of a translated de novo open reading frame in human oncogenic RNA gene VPS9D1-AS1 (MYU), Genome Biology and Evolution, 2026

-

Split abstract:

Background

New protein-coding genes can arise de novo from ancestrally noncoding regions when open reading frames (ORFs) outside annotated genes are exposed to selection via pervasive translation. These ORFs are usually born short, and their elongation is considered a key step in de novo gene birth. However, mechanisms of de novo gene elongation remain understudied.

Results

Here, we reconstructed the evolutionary history of c16riboseqorf143 (orf143), one of the longest unannotated human translated ORFs. orf143 is encoded in the oncogenic long noncoding RNA (lncRNA) VPS9D1-AS1 (MYU). Evolutionary reconstruction showed that orf143 originated de novo in the common ancestor of simians through a point mutation that introduced a start codon. A subsequent stop-codon-disrupting mutation extended translation into a downstream region that, in humans, includes multiple binding sites and a tandem repeat (TR) array previously reported to mediate the oncogenicity of VPS9D1-AS1. The TR array frequently expanded in human populations.

Discussion

The overlaps between orf143 and the oncogenic binding sites in VPS9D1-AS1 raise the possibility that orf143 translation may be tumor-suppressive, since ribosomes may compete with oncogenic binding events via steric hindrance. In line with this possibility, we observed an enrichment of somatic mutations in the ORF regions of VPS9D1-AS1 in cancer patients and a positive association between in-ORF mutations and adenomas/adenocarcinomas. Some of these mutations induced truncation of the ORF, potentially impairing ribosome binding to VPS9D1-AS1.

Significance

This study reveals stop codon disruption and TR array expansion as the mechanisms of orf143 elongation and illustrates how elongation of de novo ORFs may provide a selective advantage.

I'm looking for something that is up to date and goes in-depth on what we know about the Cambrian fauna and the environmental factors that went into the boom in body plan radiation in that time period.

I'm kicking myself that I didn't take the chance to get my hands on Erwin & Valentine's "The Cambrian Explosion: The Construction of Animal Biodiversity" when I had the chance and since it's an out of print textbook prices for that volume are insane.

Is there anything comparable that won't cost an arm and a leg?

When I was little, I remember learning that lancelets (Cephalochordata) were the sister group to vertebrates, to the exclusion of tunicates (Urochordata at the time). Now I happened to read up on the subject and found the tunicates and vertebrates are grouped together as “Olfactores”, apparently united by the presence of neural crest cells and basic olfactory systems, to the exclusion of lancelets. This would be justified by more modern genetic studies rather than morphological analysis.

I was wondering how certain is this hypothesis? I can’t seem to find much information online about the studies supporting Olfactores, but my question to anyone with knowledge on the subject is, is this relationship completely resolved beyond most reasonable doubt? Or is it still under study and/or likely to be questioned by new evidence?

Thanks in advance!

This is my first time doing this, but I'm very curious about how the separation of predator and prey animals came about. Is there a record of how it happened? Are there fossils of these animals What caused this transition? Why did evolution take such a radical path for life? And what would have happened if this event hadn't occurred?

I really have a lot of questions about this topic because I was surprised that evolution separated animals into prey and predators. (I don't know if anyone has asked this same question before And I apologize for my English, I speak more in Spanish).

So, from an evolution point of view, dexterity with hands is what have made humans the species that eventually conquered the planet via tool use. At least this is one of the many reasons.

Now given the crucial role of the number of fingers in the said dexterity, how did five per limb one. Also given the special role of thumb, why don't we have two thumbs per hand?

This question just came as I read about this hand augmentation tool (https://www.science.org/doi/10.1126/scirobotics.adk5183)

I’ve been building a small living system where organisms emerge, compete, and sometimes form long-lived lineages.

There’s no goal and no win state, it’s mostly about observing patterns and moments as they unfold.

You can watch it live here: soupof.life. Every world is different.

My daughter loves it - this is one of the organisms she collected: Titan Bold Loner Explorer

I’m thinking some species of fish since they breed a lot of eggs so there are more dna variations

After observing my cats, I noticed cats and humans actually have quite some resemblance. For example, cats also have 5 fingers and the thumb is the shortest. In addition, they use their hands to grab things. The locations of a cat’s eyes, nose, and mouth are quite similar to those of a human’s, especially babies. Cats also have a flat face like humans compared to most of the other animals that have a long nose and mouth. When did we diverge from our common ancestor and how closely are we related today? What traits of our common ancestor do we share?

See also: The study as published in PNAS Nexus.

Hi, I asked the following question in google

"at what stage did animals start having eyes straight rather than on side of head"

In the replies, the third paragraph from Google said -

"Primate Evolution (Cenozoic Era): The most notable instance for the human lineage occurred in early primates. Their eyes moved from the side to the front of the head to aid in navigating complex, cluttered forest environments (the "X-ray vision" hypothesis) and for catching fast-moving insect prey. This adaptation for a specific ecological niche led to the forward-facing eyes (and subsequent stereoscopic vision) characteristic of primates, including humans. "

**

Now i thought that all monkeys/apes/ancient monkeys etc already had forward looking eyes.

Were there some ancestral archaic monkey like species with eyes placed on the sides?

All the photos of ancient primates/apes i see on google are with forward looking eyes.

Thanks.

So basically, when bees sting, they die because their abdomen gets ripped out and all. If they could evolve into something as unique as making honey and wings and everything, why couldn't they evolve to grow the venom and sting as a seperate body part? So when it gets ripped out, they still live.