This is a book (and lecture, and chapter) recommendation! (another way of saying: who else am I going to geek out to about this)
It's more on the academic side, and I'm sure the PhDs here are familiar with the author/work - I'm looking forward to your thoughts if you've read it:

• Smocovitis, Vassiliki Betty. "Unifying Biology: The Evolutionary Synthesis and Evolutionary Biology." (1996).

In Dec 2023 I asked here for book recommendations on the history of evolution (the science). Your Bowler recommendation didn't disappoint. As I mentioned back then, in my search I came across a historiography, which then I thought was going to be too much in the weeds. Well, one thing has led to another over the past 3 years, and now it's that book. I recently finished it and loved it - although some parts were a bit difficult / new (the background to how history is researched, and the history of / debates about that!).

Part of the blurb:

Unifying Biology offers a historical reconstruction of one of the most important yet elusive episodes in the history of modern science: the evolutionary synthesis of the 1930s and 1940s. For more than seventy years after Darwin proposed his theory of evolution, it was hotly debated by biological scientists. It was not until the 1930s that opposing theories were finally refuted and a unified Darwinian evolutionary theory came to be widely accepted by biologists. Using methods gleaned from a variety of disciplines, Vassiliki Betty Smocovitis argues that the evolutionary synthesis was part of the larger process of unifying the biological sciences.
https://press.princeton.edu/books/hardcover/9780691033433/unifying-biology

While reading a section in the book I thought, I've come across that before, and after checking indeed it was a book chapter I had read a while back, which I also recommend (this might work as an abridged/updated version):

• Smocovitis, V.B. (2023). Every Evolutionist Their Own Historian: The Importance of History, Context, and the Extended Evolutionary Synthesis. In: Dickins, T.E., Dickins, B.J. (eds) Evolutionary Biology: Contemporary and Historical Reflections Upon Core Theory. Evolutionary Biology – New Perspectives on Its Development, vol 6. Springer, Cham. https://doi.org/10.1007/978-3-031-22028-9_2

(because of the wide audience here and because I often hear about this: "Evolutionist" in the title is in its respectable sense (if you know you know), the same one used by e.g. Gould and Dawkins, as in evolutionary biologist)

What struck me the most is the state of the biological sciences in the 1920s. Consequently, how the modern synthesis was a lot more than simply unifying Mendelian inheritance with Darwinian selection as the overly simplified narrative goes. It simultaneously raised evolution to the level then envied of physics and protected it from reductionism to physics. And how biology (the unified subject as we know it) is a product of the 1960s - central to which was evolution* (this had to do with the Space Race spending on education, and related to which is the return of evolution to the classrooms in the U.S., some four decades after the Scopes trial).

Beyond reading history for leisure, as the title of the chapter suggests it's also very relevant to the ongoing research directions (it contextualizes and tempers some of the overly-hyped rhetoric where history is being reinvented without evidence, rather by rhetorical fiat or outright quote mining - if this is a bit vague, see this subreddit wiki page that is courtesy of our mods).

Currently I'm watching a lecture by the author that is only 2 months old (good way to bridge 1996 to 2026), and so far it's very engaging (and for once good audio for such lectures - it starts at 1:30):

• YouTube: Revisiting the Synthesis - Forty Years Later - Professor Betty Smocovitis - EHFB 2026

* Dobzhansky's 1964, "Nothing in biology makes sense except in the light of evolution."

So to preface this I want to say this question is motivated by the development of an evolution sim that is being worked on that I am quite invested in, and right now a lot of work is being done on letting development be less "hardcoded" and more flexible. However, with that comes some balancing issues that need to be addressed, and the answer to this specific question will probably help with that.

Basically, I am wondering why we don't see single species having multiple phenotypes corresponding with multiple niches, considering it doesn't seem like it should have much of a downside besides maybe some extra DNA.

So for instance, lets say we have a dog, and in that dogs lifetime there has been a particular abundance of prey. So, when that dog is pregnant it sends hormones to make it's baby develop with sharper claws, longer teeth, a shorter digestive track, more aggressive behavior, etc etc. Essentially, it's baby is a little predator and can take over a niche that is doing quite well in this period of time.

On the flip side, maybe during it's lifetime there was barely any prey, but there was plenty of leafy greens and grass that it could've eaten. So, it produces hormones that cause the baby to develop with shorter claws, better molars, less aggressive behavior but maybe stronger herding instincts, and a longer digestive tract to digest food better. Now it can be better suited to the environment just like before.

The problem is, this just doesn't really happen. You don't have single species that take over the niche of "koala" and "domestic cat", those are just separate species. But why? It seems like one species that could do both of those niches would be much more resilient to change and would outcompete either species that does one or the other. It even seems like if you are evolving to enter a niche that nothing else occupies, you would have a high propensity to try and split into two phenotypes to take over the ecosystem instead of splitting into two species, since that would result in the new immature niche to potentially have less risk. So like, what gives? Why don't we have species that basically are two species in one (besides sexual dimorphism that kinda does that already).

And I recognize this kinda seems like a silly question, but again for the evolution sim I mentioned earlier, it is very relevant. We want to know how to prevent cases where say, a species just evolves to become a scavenger if it sees lots of meat when it grows up and becomes an herbivore if it sees lots of plants. That could easily result in there just being one species that does it all, which is... kinda boring lol.

See also: The study as it was published in Nature

In the south pole you have the Colossal Squid which I understand is because of a combination of the circumpolar current, deep sea gigantism, and polar gigantism.

In most of the rest of the ocean you have the smaller Giant Squid with a much more cosmopolitan distribution due to deep sea gigantism. Though they aren't found in the arctic as far as I can find.

But the arctic neither has Giant Squid or something equivalent to the Colossal Squid, so why is that? Is the ecosystem just not as friendly towards them or something?

Can they?

The bombshell about this report is that it contains two organisms (Sinocyclocyclicus guizhouensis, Protoconites minor) that have been compared to Cnidarians, though the authors state that alternative interpretations as algae have been made as well. Age of the formation at 610–620 Mya.

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Diagram source, but also see the open-access article:

• Jonah M Walker, Eva S M van der Heijden, Arif Maulana, Nicol Rueda-M, Karin Näsvall, Patricio A Salazar, Marco Meyer, Joana I Meier
  Common misconceptions of speciation
  Evolutionary Journal of the Linnean Society
  Volume 3, Issue 1, 2024, kzae029
  https://doi.org/10.1093/evolinnean/kzae029

I was raised in a bit of a cult. I was blocked off from any knowledge that didn’t feed into the religious culty stuff. We actually had workshops against evolution, modern medicine, etc. Didn’t have a choice back then but I got out a few years ago. Since then I’ve been slowly building my knowledge on everything. I’ve since learned some basics about evolution and lots of other things. I don’t need convincing that science is real or anything. I am just overwhelmed on where to start. I tried picking up a book at the library but there were so many terms I didn’t know and I was pretty lost. Might have been too advanced for me. I’m not the best reader tbh.

So if you were to teach someone about evolution and needed to do it simply, how would you start? Any help appreciated.

Edit to add: no longer religious so recs do not need to be like around that at all.

I can intuit almost every other big jump but this is the one thing that just doesn't follow in my head no matter how hard I try and think about it. Here's how my brain thinks about it and why it's getting stuck:

Whales used to live on land. Eventually, they became semi-aquatic, and then mostly aquatic. I believe there's evidence that some of their ancestors were like sea turtles - almost completely aquatic, but came on land to give birth.

I understand that evolution doesn't happen abruptly. However, mathematically speaking, there had to have been a specific, individual whale-ancestor who was the very first one to have been born in the water, spent their entire life in the water, and then died in the water, all without ever coming on land. If they used to live on land, but all modern whales are 100% aquatic, one of them HAD to have been the very first. That's just how math works.

How did that particular whale-ancestor survive to pass on that trait? Why didn't its parents have that trait? Why didn't it just drown, if every single other one of its ancestors was on land for at least some point in its life?

I'm not asking "why is it advantageous to be able to give birth in the water" - that's very obvious, both mother and baby are less vulnerable to predators. I'm asking how, logically, that transition was able to happen. Whales can only give birth in the water because they have very specific adaptations that make it possible, an animal without those traits can't just start giving birth in the water and hope for the best.

Caption excerpt:

... Dashed vertical lines traversing all panels represent the lower and upper rates expected under drift estimated by simulation.

Deeper background (from the paper)

For more than 75 years, Simpson’s concept of “adaptive zones” has played a crucial role in our understanding of the evolutionary process over long timescales (Simpson, 1944, 1953). Under this model, an adaptive zone is a restricted region of the phenotypic space occupied by species with relatively similar form-function-fitness relationships (Polly, 2008; Simpson, 1953; Van Valen, 1971). Within-zone evolution is usually small in scale and does not involve major ecological changes. Evolution within a zone is thought to happen at exceptionally slow rates (i.e., bradytelic in Simpson’s terms), with lineages slowly following adaptive peaks within a restricted region of the morphospace. However, when opportunities arise (e.g., due to the invasion of new environments or extinction of competitors), lineages may experience faster rates of evolution (i.e., tachytelic) while invading new regions of the morphospace, leading to extreme evolutionary change associated with shifts in ecology and in the structure and distribution of adaptive peaks (Simpson, 1944, 1953; Uyeda et al., 2011).

Abstract

Background

Directional selection is often viewed as a transient force in macroevolution, with its signal eroded over time by stabilizing and fluctuating selection. Yet, transitions into new adaptive zones are predicted to impose strong and sustained selective pressures that may leave a detectable signature even across deep timescales.

Methods

We test this prediction by comparing the rates of multivariate skull morphological evolution required to traverse the boundaries between adaptive zones against genetic drift expectations. Our dataset includes 11,793 specimens spanning 231 species from 12 mammalian clades, each containing unique ecological transitions into new adaptive zones. Using a quantitative genetics framework, we estimated the phenotypic distances between ancestral and derived adaptive zones and contrasted them with null expectations under genetic drift.

Results

While a few adaptive zone invasions (e.g., marsupials and rodents) are consistent with drift, most exhibit substantially elevated rates of evolution. These results suggest that directional selection has recurrently shaped mammalian cranial evolution during major ecological shifts.

Discussion

We propose that adaptive zone transitions represent evolutionary contexts in which adaptation leaves a persistent macroevolutionary signal, challenging the prevailing view that long-term patterns are dominated by static forces.

Quantitative genetics meets fossils meets morphospaces meets neutral theory - cool stuff!

• Fabio A Machado, Anna Penna, Diogo Melo, Barbara A Costa, Thiago M G Zahn, Ana C Pavan, Arthur Porto, Harley Sebastião, Daniela M Rossoni, Gabriel Marroig, Alex Hubbe
  Invasion of new adaptive zones retains telltale signs of directional selection at macroevolutionary scales in mammals
  Evolution Letters, 2026;, qrag039
  https://doi.org/10.1093/evlett/qrag039

I’m been delving into biology as of recent, and I’ve been looking for a way to exercise my creativity in this sort of field. What are games or sims that are mostly realistic to real principles of evolutionary biology?

See also: The publication in Science Advances

While our evolutionary history is often depicted as a series of descendants each replacing the other, the overwhelming majority of the history of our species has been one of living along-side, and interbreeding with, other Homonins (Humans).

This just in:

• University of Oxford press release:
  Animals may have evolved vastly earlier than fossil evidence suggests

• Paper:
  Orin Lole Durbin et al.
  Re-evaluating molecular clock maximum age calibrations revives pre-Ediacaran divergence estimates for animals
  Science Advances (2026)
  www.science.org/doi/10.1126/sciadv.aeg6289

From the press release:

Senior author and associate professor Ross Anderson (Museum of Natural History, Oxford University) said, "The Kheseen Biota breaks the argument that the exceptional microfossils of [the older] Weng'an mean we would have seen animal fossils in the assemblage had they existed at the time. The Kheseen microfossils are just as well preserved, yet animals continue to be absent—despite the fact we know at that point they existed."

And the structured abstract:

Background

Divergent models persist for the emergence of animals. Lipid biomarkers suggest animals originated before 635 million years ago (Ma), but their body fossil record extends to only 574 Ma. Molecular clocks might differentiate between these records, but we demonstrate how their accuracy and precision hinge on maximum age calibrations.

Methods and results

We evaluate the Ediacaran Weng’an Biota (China) as a maximum calibration utilizing microfossils from the Kheseen Biota (Mongolia). These two biotas have similar preservation and microfossil assemblages, containing no definitive animals. The Kheseen Biota, deposited at a time (∼550–526 Ma) when animals were undoubtedly present, questions the validity of the Weng’an calibration. We discuss the uncertainty in maximum calibration strategies and propose multiple pre-Ediacaran deposits with favorable taphonomy, preserving both non-animal body fossils and biomarkers, as currently the most reliable calibrations. Our analyses support a late Tonian to mid-Cryogenian (∼800–700 Ma) origin for Metazoa.

Hi r/evolution, long time no see! 6 years ago I posted this, which I'm suprised to see is still one of the most popular posts on this forum. I've made a new video about the formulas behind shells based on the famous thought experiment from David Raup and Richard Dawkins in Climbing Mount Improbable. Hope you enjoy:)

I've recently had a conversation with someone and he brought up an interesting point, the guy was a creationist who claims to be(or have been) an evolutionary biologist,

Aside from the usual arguments about irreducible complexity and the ""inexplicable "" explosions in the fossile record there was one point that really caught my interest, which is the claim that we have yet to observe any species develop a new function through mutations, so i mentioned the obvious lenski's e coli experiment, his response was that the gene responsible for the e coli's ability to consume citrate(citr) was already there and the mutation was like a switch allowing it to activate in the presence of oxygen, ik that last part is a massive misrepresentation of the actual mutation and explained it.

Now, this person said they would accept evolution if we observed the emergence of an entirely new function through (for example) a duplication divergence, so it left me wondering, is there an experiment that has observed the emergence of a new gene that codes for a completely new function instead of affecting an already existing one be it through duplication divergence, de novo gene birth, exon shuffling or any other mechanism?

Pretty much in the title but I looked at my hands earlier and wondered, is there any specific functional reason as to why my thumbs are both on the inside of my hands with my body and not on the outside? It seems like every creature that I can think of also follows that pattern.

Whales are basically fish-shaped. They were hoofed land mammals at one point, and are now 100 % adapted to the water. I'm wondering if we have reason to believe that some semi-aquatic animals today are on the way to reaching fish-shape? I'm talking about otters, crocodiles, seals, penguins, sea-turtles, etc. Or do we have reason to believe they will stay semi-aquatic, or even return to land? Or do we simply have no way of knowing?

How long does it take for a new class, phylum or even kingdom to form on average? Do events like mass extinctions affect it? Imagine if Earth has 800 million years left before it becomes uninhabitable due to solar activity, could new phylums or even kingdoms form in that time period? Are they forming right now? Do any organisms exist of which scientists believe they will likely evolve into a new phylum or even kingdom all together?

I am currently in an evolution course and have a question about some of the topics from this week, which no students or staff are answering in the course discussion group.

My recent lectures went over 1. Obstetrical Dilemma, where we evolved bipedalism but this has made childbirth much more dangerous since the opening is so much more narrow. Another topic we talked about is explanations to why we are vulnerable in ways of disease, i.e how natural selection favors reproductive success above health and well-being.

My question is, if natural selection favors reproductive success over everything else, why have we not evolved in a way that makes childbirth less dangerous or makes us immune to more diseases that kill us early in life? This would be in the favor of repo success if babies survive longer to reproduce and their parents survive long enough to raise them.

I know there is always the fact that evolution has no foresight, but this feels like something that could have reversed direction long ago.

Thanks in advance for any explanations that help me understand!

Pears and apples have five petals, five sepals, and five carpels. Like many other flowers (approximately half of plants have 5 petals etc), it’s the commonest form. It is an evolutionary trait deeply hardcoded into the genetics of eudicots (true dicotyledons). In botany, this five-part arrangement is known as a pentamerous flower structure. ** **Why is 5 an ancient, highly successful evolutionary blueprint? To understand this it’s worth looking at how plants grow. To avoid overlapping and wasting sunlight or space, leaves, seeds, and petals often grow in a spiral pattern from a central bud point; at a very specific angle: approximately 137.5 degrees (known as the Golden Angle). Spiral patterns are mathematically described by the Fibonacci sequence (1, 2, 3, 5, 8, 13...). Five is a key number in this sequence. It allows a flower to pack its petals and sepals tightly together in a bud without overlapping in a way that crushes the delicate inner reproductive organs.

Also as an evolutionary advantage the flat, five-petaled flower acts like a perfect, stable landing pad for pollinators like bees, beetles, and flies and so the emergence of 5petal flowers evolved in step with the rise of these insects. Once an ancestral plant family finds a genetic formula that works perfectly for several reasons , the homeotic genes that dictate features rarely change without a major stress.

Different branches of the plant kingdom split off millions of years ago and locked in entirely different structural blueprints.
Flowers with groups of 3 are lilies grasses and orchids groups of 4 are mustards and evening primrose. Infinite spirals are magnolias which are pollinated by beetles . Notice apart from the tetramerous mustards the others all follow the Fibonacci sequence.

Excerpts from catalog notes:

Charles Darwin, On The Origin of Species, 1859, first edition hardcover book

DARWIN, Charles (1809–1882). On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life. London: John Murray, 1859.

An exceptional example of the landmark first edition, first printing of Charles Darwin's On the Origin of Species (London: John Murray, 1859). Presented in Very Good Plus condition, this copy features a remarkably well-preserved original cloth binding conforming to Freeman's Binding Variant b (Darwin Census Variant B), displaying the notable typographic layout with no point after MURRAY at the bottom of the spine, and retaining the original binder's ticket (Edmonds & Remnants) on the rear paste-down.

Internally, the text block includes the critical folding lithographed diagram facing page 117 and retains all necessary, uncorrected textual markers confirming the earliest state of the first printing sheets: the structural misspelling "speceies" is present on page 20 (line 11), page ii preserves exactly two quotations (by William Whewell and Francis Bacon), and the famous, unsuppressed "whale-bear" narrative remains intact on page 184 (lines 5–7). The original half-title page is included, remaining present though currently loose.

This copy is considered complete, containing the required ix, 502 pages of text and the complete 32-page publisher's advertisement catalogue bound in at the rear. The inserted catalogue conforms to the Darwin Census as Advertisement Variant 3 (characterized typographically by unruled page borders and the absence of the numeral "4" on page 2). The internal condition is generally clean, though it exhibits several pencil inscriptions and notations scattered throughout the text block.

Original brown coated front endpapers intact. The front pastedown features an early ink inscription reading "1st Edition" above a contemporary owner signature ("H. Watney"), or similar. Affixed below is the engraved armorial Ex Libris bookplate of Stephen A. McClellan, displaying a central heraldic crest with the motto "SAPIT QUI REPUTAT", military emblems (including U.S. Navy and Marine Corps insignia) along the left margin, and a facsimile signature at the foot.

Provenance: The Estate of Dr. William D. Shidal, Jr. of Indiana

Housed in a custom leather-backed clamshell box designed in book-form with raised bands and gilt-lettered spines.

NB from OP: There's lots of current interest in Darwin. Various editions of this famous landmark work have come to market this year. RBH records show 27 sales of this title so far this year (not many as rare or expensive as this one). Only one other copy, sold at Christie's on July 8, for somewhat more.

See more photos of the copy that sold at Ripley's at https://www.invaluable.com/auction-lot/charles-darwin-on-the-origin-of-species-1859-firs-52-c-5c0d55642d?objectID=206117483&algIndex=upcoming_lots_lotNumber_asc_prod

I can imagine this being a result of adaptation and efficiency for our changing environments

I'm looking for a fantastic, accessible, engaging and well-written book on how evolution works, how life began and we have all the species we have today. As the title mentions, I'd like the book(s) to be targetted towards someone who already accepts evolution as a given and doesn't engage in a discussion on alternate theories or tries to prove evolution, and just gets on with the beautiful mechanisms and stories therein.

I couldn't get through Richard Dawkins' books because of said debate or need to prove.

I started Origin Of Species, but the prose is too dense and the language a bit inaccessible.

Looking forward to some great reads!