In press.
From the accepted manuscript:

In Wilson’s (1961) formulation, Stage I describes the geographic expansion phase of a generalist species as it first colonizes marginal, beach-front habitats across a novel island or archipelago (Fig. 1A). Stage II reflects evolutionary differentiation from mainland conspecifics as populations adapt to local environments and expand into empty interior niches. Continued invasion by competing Stage I and II species drives character displacement and progressive range contraction, ultimately producing Stage III relict taxa, characterized by highly specialized lineages vulnerable to extinction across the archipelago. Ricklefs & Cox (1972) later extended the model by adding a fourth stage, describing highly differentiated single-island endemics.

Abstract

Background

Modern phylogenetic evidence offers novel opportunities to test classic models in island biogeography. One of the earliest, E. O. Wilson’s Taxon Cycle, proposed that insular lineages progress through sequential and predictable phases, beginning with geographic expansion, followed by ecological specialization, and ultimately range contraction (and even extinction), shaped by dispersal and interspecific competition. However, despite renewed interest in the Taxon Cycle, the extent of empirical support for its predictions and its broader significance within contemporary evolutionary biogeography remain unclear.

Methods and results

Here, we evaluated the strength of support across 50 studies of diverse archipelagos and taxonomic groups using an evidence-graded classification scheme based on data type and inferential strength. We found evidence for taxon cycles in 82% of these studies, with 54% supported by time-calibrated phylogenies and 32% also providing explicit tests of ecological and evolutionary mechanisms. Notably, one-third of studies supporting taxon-cycle dynamics were not designed as explicit tests of the Taxon Cycle yet recovered patterns consistent with its predictions. Support based on temporal or mechanistic evidence was concentrated in Oceanian, Australasian, and Neotropical systems, with lineage origins most frequently estimated at approximately 5–20 Ma. Trait-mediated dispersal and ecological interactions were identified as key mechanisms associated with stage transitions. However, we did not find strong support for continental examples (based on habitat mosaics).

Discussion

Together, these results show that the Taxon Cycle has evolved into an increasingly generalized predictive framework for understanding island diversification, with potential applications to biodiversity conservation, especially concerning invasive species.

• Ivan V Monagan, Christopher J Raxworthy
  Phylogenetic evidence for the Taxon Cycle: contemporary tests across island and continental systems
  Evolutionary Journal of the Linnean Society, 2026;, kzag029
  https://doi.org/10.1093/evolinnean/kzag029

Hey guys!

I am working on an evolution video game (sort of like Spore but not Spore) and I want to implement a detailed creature editor where one can add organs, bones, senses etc. I am a physics graduate and not a biologist so please forgive my lacking understanding of anatomy.

I want to begin by implementing the spine/vertebrae since this seems like a good starting point and encapsulates essentially all of chordata since a notochord is more-or-less a primitive spine. To keep my editor as general as possible I need to utilise the homology that connects as many clades as possible. While I find the homology between legs, arms and wings easy-to-follow I am having a hard time understanding the homology behind vertebra which is why I am resorting to you guys.

In the attached image you find an image of what I was able to gather as vertebra's most prominent features. I was able to find out that there are species which in addition to a dorsal arch contain a ventral one which does not encapsulate the spinal cord but rather a blood vessel. I then also found out that human cervial vertebrae have something similar but instead of one central passage we got two lateral passages for blood vessels. After looking at the human skeleton I also began to wonder whether the the shaded part of the bone is homologous to ribs which just fused into the vertebra. I am also unsure how the air pockets in dinosaurs come into play.

Note that this sketch is only supposed to capture the essential topology of vertebra. Features such as the sail of the spinosaurus are just an elongation of the dorsal "thingy" (spinous process if I am not mistaken).

So my question to you guys is whether there are any important features I may have overlooked? I am aware that its impossible to capture all of chordata with this simple classification, but I want to try to capture as many clades as possible nonetheless.

I am looking forward to your insight! :)

What was the evolutionary reason for the protruding brow ridges that Neanderthals and other ancient humans had? I heard it could have been to protect the head during fights.

Hello everyone! I'm getting my master in evolutionary biology so I wanted to ask if you have any youtube channels you love that talk about evolution. Not to study but just for fun and curiosity (I am already pretty on spot with a lot of subjects but you never stop learning!).

Ungulate biomass availability in certain parts of sub saharan africa are up to 10x that of the russian far east, yet siberian tigers are significantly larger than most african lion populations. Under conventional evolutionary theory, wouldn't limited prey availability drive siberian tiger size down while high prey availability plus much higher competition drive lion size up?

See also: The study as it was published in the journal Anatomical Review.

I asked this over on r/whales , but it might fit better here.
It’s fairly obvious why Lake Superior couldn’t support a blue whale type population. However, given that there are plenty of dolphins and porpoises in rivers and freshwater, and that there are seals that are isolated in lakes, most notably Baikal, but also several other isolated lakes, why are there no isolated cetacean populations in any lakes? Obviously seals can get on land a little better, but not really past the shoreline. Every dolphin could get to the ocean right now if it wanted to, but that’s not true for seals, how come?

Hey guys, I decided to start a little project on my own, I hope its okay if I share some of my progress here: I started experimenting around with some macroevolutionary models and implemented a simple DE solver alongside a neat vibe-coded interface which shows me how species within my model grow and evolve. Am hoping to implement this engine in a Spore-like videogame one day!

My idea essentially is that the player can control an evolutionairy force to "guide" certain features according to their liking. The other species evolve autonomously according to what essentially is the canoncial Lande equation. Instead of however simulating thousands of creatures in a real environment I decided to use a mathematical abstraction which captures all of evolutions' most essential features. That way the evolution of tens of thousands of different species, each with millions of individuals, can be simulated in the background with relatively good precision. I was surprised to see that my relatively simple model was also able to replicate some real-life phenomena, like the latitudinal gradient in biodiversity, which I didn't anticipate.

I came across this and it was too delicious not to share (my bold emphasis).
I'd love to hear from our resident pop-gen pros.

... hold a minute: the fact that certain species have certain genes in common, and differ in other genes, does not prove that the assortment of a species’s genes constitutes the essence of its specificity. In fact, Leo Berg used Vavilov’s data to demonstrate just the opposite! Berg considered the fact that very different species have Mendelian genes in common as evidence that species specificity was not determined by Mendelian genes, and there is contemporary evidence that Vavilov agreed (Berg 1926; Haldane 1932: 66, 79; Adams 1978b).⁴ Thus, Haldane recognized the problem but did not resolve it. To be sure, if one accepted the proposition that varieties and species were qualitatively the same and that the only difference between species laid in their complement of Mendelian genes, all is in order; but if one didn’t accept it, Haldane gives no convincing reasons to change one’s mind.

The only one of the four founders of population genetics who directly confronted this central problem was Sergei Chetverikov. It was not difficult for him to do so: he had worked for 20 years as one of Russia’s leading butterfly taxonomists. An entomologist and systematist, he actually first taught genetics in a course at Moscow University entitled “Theoretical Systematics.” In Chetverikov’s classic work of 1926, “On Certain Aspects of Evolution From the Viewpoint of Modern Genetics,” the entire first section addressed the central problem. There, he argued that the traits determined by Mendelian genes in Drosophila (e.g., venation and wing structure) are the very same traits which are “fundamental in modern systematics for distinguishing higher systematic categories” (Chetverikov 1926: 9–10). Elsewhere in this same section, he mobilized his considerable knowledge of the systematics and classification of Diptera and Lepidoptera to make the same point.

--

Footnote 4
When I was visiting Stephen Jay Gould one evening at his Cambridge home, he told me that he was much taken by this realization after reading my article on Vavilov, and used it as the basis (unattributed) for one of his popular science columns. (His personal thanks was the best apology for failing to mention my article as his source!) As for Haldane, he referred to Berg’s work as “in my judgment the best anti-Darwinian book of this century” (p. 12).

PS Chetverikov was sadly a victim of the Lysenko purge.

• Adams, M.B. (2021).
  Little Evolution, BIG Evolution: Rethinking the History of Darwinism, Population Genetics, and the “Synthesis”.
  In: Delisle, R.G. (eds) Natural Selection.
  Evolutionary Biology – New Perspectives on Its Development, vol 3. Springer, Cham.
  https://doi.org/10.1007/978-3-030-65536-5_8

Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species is used to classify but before all of these would be the LUCA. Species just describes life that diverged more recently than Genus or Family but as time passes those will further diverge. Will we eventually need more categories? Isn't this kind of a short-sighted way of describing life?

i have a hard time judging this for myself. I think it’s neat to when experts apply game theory to evolution to describe things but they will warn, “is is very abstract”. But then isn’t nearly all of it abstract? Fitness, selective pressure, natural selection, all that feels just as abstract as game theory to me.

I know there is some stuff thats concrete such as DNA (which has its own abstractions in its field I assume) and its mutations.. is it all abstraction after that?

I believe there is an explanation for this, something to do with brain wiring, but I am wondering if there was evolutionary advantage driving this.

Alright, I get how genetic bottlenecks work, a species/population has a decline, which reduces genetic diversity which decreases its chances of adapting to changing pressures/environment and increases chances of genetic diseases.

What I dont get is how it works within evolution. So I keep seeing things about Cheetahs being nearly extinct due to genetic bottlenecks.

But also, within the theory of evolution all species on earth came from a common ancestors, and then through the genetic tree more and more species have common ancestors. Like us and apes have a common ancestor, etc.

So with this, how come a population/species cant independently within their species naturally breed more genetic diversity back into their species?

Just to be clear, I'm not saying "so therefore the theory of evolution isnt real" or "therefore genetic bottlenecks arent real", it is genuinely something I have often wondered about.

Can five unverified anecdotes support a scientific theory about near-death experiences?

A recent paper proposes that NDEs may have evolved from the same defensive response that causes animals to “play dead.” The idea is fascinating but what happens when researchers look for evidence?

This letter to the editor takes a closer look at the study’s methods, its unexpected use of five anecdotes, and the broader scientific debate over whether NDEs and thanatosis are actually comparable.

A few years ago (about 2020?), a "new paper" claimed that analysis of the x chromosome indicates human females pairing with neanderthal males was the preferred reproductive pairing.

But what was actually found on the X chromosome? And why is it assumed to reflect actual preference rather than some reproductive incompatibility?

I'm especially suspicious of this claim based on the history of the research.

The early genetic research on Neanderthals focused on the more abundant mitochondrial DNA. Noting that there was no neanderthal mitochondrial DNA in modern humans, early scientific journalism focused heavily on a fetish-like claim that neanderthal males bred with anatomically modern human females, often including some claims about brutish neanderthal men, attraction towards small, frail women, etc.

When it was found that no modern humans had neanderthal Y chromosome DNA, hardly a peep out of scientific journalists, who often assumed the hypothesis of some genetic incompatibility must be the cause.

When it was found that neanderthals had split from anatomically modern humans about 800,000 ybp, but had more sapiens-sapiens like mitochondrial, x, and Y DNA from about 400,000 ybp... Minimal coverage. When it was shown that anatomically modern male humans had introduced their Y chromosomes into the neanderthal populations and completely replaced the currently used neanderthal Y chromosome at least twice... Hardly a peep, despite the fact that this can only happen by anatomically modern human males producing sons by anatomically neanderthal females.

So for me, it seems likely that anatomically modern humans just had the more "fit" mitochondrial DNA and sex chromosomes, and I don't see what findings could have even implied anything else.

But I'm obviously not an expert geneticist... Can anyone explain how the idea that anatomically human females and neanderthal men being a "preferred" coupling even could be shown through DNA analysis?

It's well-known that horses and other odd-toed ungulates are hindgut fermenters (as opposed to even-toed ungulates, which are foregut fermenters). It's also well-known that horses are obligate nasal-breathers that can only breathe through their nostrils and not their mouth. They're also unable to vomit, and if they get some sort of stomach poisoning, they'll die since they can't puke it out.

Something I find surprising is that all three of these facts are also the case for rodents and rabbits. Rodents and rabbits are hindgut fermenters (hence why they have to eat their own droppings), obligate nasal-breathers, and unable to vomit.

So...is there a correlation between all three evolutionary adaptations, or is it just a coincidence? Does this also apply to elephants as well, since elephants are hindgut fermenters too?

I have some Questions about the evolution of the Hoatzin. The Hoatzin is fundamentally different from most other birds, the most notable difference being the claws on the wings of Hoatzin chicks. Could it be, that Hoatzin is actually a descendant of a Non-Neornithian bird clade? If the claws evolved later, my question would be how they evolved.

If anyone has any studies about Hoatzin evolution, especially regarding its claws, I would really appreciate if you could send some links.

Let’s say in like a million years chimpanzees and humans have gone extinct but the descendants of chimpanzees have evolved to fill the ecological niche of humans?

Most if not all species have their own mechanism to identify danger or pain. Is this as a results of evolution presumably that the earliest living things lacked this and were forced to generate them as a survival factor?

I read Richard Dawkin's Selfish Gene, and I'm genuinely wondering if I just tainted my brain with entirely outdated pseudoscience or a mostly credible classic that is just a bit outdated. The book was incredibly enjoyable, and honestly, it has changed my perspective as much as reading a book by Robert Sapolsky or Joseph Henrich. Are there any books you guys recommend I follow it up with to see where the debate is now? Like, books on whether multilevel selection or the EES have or something else have any merit. Is there maybe a published scientific paper meant for those who read it and want a fact check? If I wanted to reread it in the future, would you guys strongly recommend against that? Like, is that bad? Lastly, if you guys recommend any narrative or review type scientific papers that give me a hit of where the selection debate is now, please share. Oh, and I found Arvid Argren's Gene's Eye View book, so that's on my list. Lmk ya'll thoughts on that book, too.

I've read that Neanderthals had similar physical traits although due to different genes than modern humans.

For example Neanderthals had red hair but apparently a different shade because it was caused by a different gene. Same way the blonde hair in Melanasians is caused by a different gene than the one in modern day Caucasians.

I tried looking it up but the few sources I could find said Neanderthals lacked the genes causing androgenic alopecia in modern humans.

And other sources just say they didn't go bald at all. If so they were quite lucky in that department, you know aside from their whole extinction.

So did they not go bald at all or did they just have other genetics causing baldness we don't of?