#*evolution

[herpsandbirds]

100 Million Years Ago, Snakes Gained Their Most Iconic Traits

The origin story of snakes is still being pieced together, but researchers are confident that their unique jaws, lack of limbs, and elongated figure all emerged at about the same time.

Snakes seem like relatively simple creatures—basically a glorified sock with holes on either end. Yet, these creatures have managed to adapt to nearly every continent on the planet over the past 100 million years. But how exactly did snakes evolve, and what made these slithery creatures so successful across the planet today? It was likely a combination of three factors that all arose at roughly the same time. “It all happens in one singular evolutionary burst around 100 to 110 million years ago, and then after that they pretty much have free reign to the planet every time they go into a new habitat,” says Alex Pyron, a biologist at The George Washington University in Washington, D.C. ...

Read more: https://www.discovermagazine.com/planet-earth/100-million-years-ago-snakes-gained-their-most-iconic-traits

[sixteenseveredhands]

Poplar Lappet Moths: these moths are able to mimic the dead leaves of a poplar tree (there is at least one moth in each of the photos below)

Above: the photo at the top shows two poplar lappet moths disguised as foliage (the two "leaves" on the left-most end of the branch are actually moths) and the photo on the bottom shows another poplar lappet moth clinging to a leaf

The scientific name of this species is Gastropacha populifolia, but it's more commonly referred to as the poplar lappet moth. It's also known as pappelglucke in German and feuille-morte du peuplier in French.

The moths are distributed across large sections of Europe, Russia, China, Korea, and Japan, but they're regarded as a rare species throughout most of Europe.

The shape, color, wing pattern, and resting position of this species all contribute to its unique disguise, as it bears an uncanny resemblance to a dead leaf. It even has a dark, snout-like projection (the labial palpi) that mimics the stem of a leaf, and its wing pattern completes the illusion with a dark, raised line forming the central "vein" of the leaf; the soft ridges and scalloped edges of its wings also add to the effect.

There are many other leaf-mimicking moths out there, but this species is particularly impressive.

The caterpillars also have a knack for blending in -- thanks to their cryptic coloration and fuzzy, setae-lined sides, they are easily camouflaged against the bark of a poplar tree.

Above: the photos at the top show Gastropacha populifolia caterpillars blending in by pressing their bodies flat up against twigs/branches, and the photo at the bottom shows one of the caterpillars in a more conspicuous setting

These moths are defended by more than just mimicry, though; they can also produce ultrasonic clicks that interfere with the echolocation signals of predatory bats, which allows the moths to avoid being detected (and ultimately eaten) by bats.

Above: the adorable face of a poplar lappet moth

Sources & More Info:

Nota Lepidopterologica: Continuous Long-Term Monitoring of Daily Foraging Patterns in Three Species of Lappet Moth Caterpillars

Catalogue of the Lepidoptera of Belgium: Gastropacha populifolia

Moths and How to Rear Them: Gastropacha populifolia

Wikipedia (German): Pappelglucke

Moths and Butterflies of Europe and North Africa: G. populifolia

EurekaMag: Effect of the Scale Coverage of the Moth Gastropacha populifolia on the Reflection of Bat Echolocation Signals

[mindblowingscience]

Coelacanths are deep-sea fish that live off the coasts of southern Africa and Indonesia and can reach up to two meters in length. For a long time, scientists believed they were extinct. In new research published in Nature Communications, we reveal the best-preserved coelacanth fossil ever found from the ancient period hundreds of millions of years ago when these ancient sea-dwellers first evolved. The fossil comes from the Gogo Formation on Gooniyandi Country in northern Western Australia.

Continue Reading.

[realjaysumlin]

EUR0PE DID NOT CIVILIZED AFRICA - DR HENRIK CLARKE

My professor taught us well because he didn't believe in anything white, it's a social construct to empower themselves while destroying others. Weak men fear free and independent women, strong men only love and appreciate a strong Black Indigenous Woman who loves herself and her family and she will never tolerate her enemies and oppressors because for this type of Black Indigenous Lady, she will never allow herself to be used by the people who destroyed her beautiful Black Indigenous Family.

[o-craven-canto]

Filters in the way of technologically advanced life in the universe and how likely I think they are

1. Abiogenesis (4.4-3-8 billion years ago): Total mystery. The fact that it happened so quickly on Earth (possibly as soon as there was abundant liquid water) is a tiny bit of evidence for it being easy. Amino acids and polycyclic hydrocarbons are very common in space, but nucleotides aren't, and all hypothetic models I've seen require very specific conditions and a precise sequence of steps. (It would be funny if the dozen different mechanisms proposed for abiogenesis were all happening independently somewhere.)

2. Oxygenic photosynthesis (3.5 billion years ago) (to fuel abundant biomass, and provide oxygen or some other oxidizer for fast metabolism): Not so sure. Photosynthesis is just good business sense -- sunlight is right there -- and appeared several times among bacteria. But the specific type of ultra-energetic photosynthesis that cracks water and releases oxygen appeared only once, in Cyanobacteria. That required merging two different photosynthetic apparati in a rather complex way; and all later adoptions of oxygenic photosynthesis involved incorporating Cyanobacteria by endosymbiosis. For all that it's so useful, I don't know if I'd expect to see it on every living planet.

3. Eukaryotic cell (2.4 billion years ago?): Probably the narrowest bottleneck on the list. Segregated mitochondria with their own genes and a nucleus protecting the main genome are extremely useful both for energy production (decentralized control to maximize production without overloading) and for genetic storage (less DNA damage due to reactive metabolic waste). But there's a chicken-and-egg problem in which incorporating mitochondria to make energy requires an adjustable cytoskeleton, but that consumes so much energy it would require mitochondria already in place. Current models have found solutions that involve a very specific series of events. Or maybe not? Metabolic symbiosis, per se, is common, and there may have been other ways to gene-energy segregation. Besides, after the origin of eukaryotes, endosymbiosis occurred at least nine more times, and even some bacteria can incorporate smaller cells.

4. Sexual reproduction (by 1.2 billion years ago): Without meiotic sex (combining mutations from different lineages, decoupling useful traits from harmful ones, translating a gene in multiple way), the evolution of complex beings is going to be painfully slow. Bacteria already swap genes to an extent, and sexual recombination is bundled in with the origin of eukaryotes so I probably shouldn't count it separately (meiosis is just as energy-intensive as any other use of the cytoskeleton). Once you have recombination, life cycles with spores or gametes and sex differentiation probably follow almost inevitably.

5. Multicellularity (800 million years ago?): Quite common, actually. Happens all the time among eukaryotes, and once in a very limited form even among bacteria. Now we'd want complex organized bodies with geometry-defining genes, but even that happened thrice: in plants, fungi, and animals. As far as I know, various groups of yeasts are the only regressions to unicellularity.

6. Brains and sense organs (600 million years ago): Nerve cells arose either once or twice, depending on whether Ctenophora (comb-jellies) and Eumetazoa (all other animals except sponges) form a single clade or not. Some form of cellular sensing and communication is universal in life, though, so a tissue specialized for signal transmission is probably near inevitable once you have multicellular organisms whose lifestyle depends on moving and interacting with the environment. Sense organs that work at a distance are also needed, but image-forming eyes evolved in six phyla, so no danger there (and there's so many other potential forms of communication!). Just to be safe, you'll also want muscles and maybe mineralized skeletons on the list, but I don't think either is particularly problematic. An articulated skeleton is probably better than a rigid shell, but we still have multiple examples of that (polyplacophorans, brittle stars, arthropods, vertebrates).

7. Life on land (400 million years ago): (Adding this because air has a lot more oxygen to fuel brains than water (the most intelligent aquatic beings are air-breathers), and technology in water has the issue of fire.) You're going to need a waterproof integument, some kind of rigid support system, and kidneys to regulate water balance. Plenty of animal lineages moved on land: vertebrates, insects, millipedes, spiders, scorpions, multiple types of crabs, snails, earthworms, etc. Note that most of those are arthropods: this step seems to favor exoskeletons, which help a great deal in retaining water. Of course this depends on plants getting on land first, which on Earth happened only once, and required the invention of spores and cuticles. (Actually there are polar environments where all photosynthesis occurs in water, but they are recently settled and hardly the most productive.)

8. Human-like intelligence (a few million years ago?): There seems to a be a general trend in which the max intelligence attainable by animals on Earth has increased over time. There's quite a lot of animals today that approach or rival apes in intelligence: elephants, toothed cetaceans, various carnivorans, corvids, parrots, octopodes, and there's even intriguing data about jumping spiders. Birds seem to have developed neocortex-like brain structures independently. Of course humans got much farther, but the fact that even other human species are gone suggests that a planet is not big enough for more than one sophont, so the uniqueness of humans might not necessarily imply low probability. (We seem to exist about halfway through the habitability span of Earth land, FWIW.) The evolution of sociality should probably be lumped here: we'll want a species that can teach skills to its offspring and cooperate on tasks. But sociality is also a common and useful adaptation: many species on our list (octopodes are a glaring exception) are intensely social and care for their offspring. I mentioned above that the land-step favors exoskeletal beings, which in turns favors small size; but the size ranges of large land arthropods and very intelligent birds overlap, so that's not disqualifying.

9. Agriculture and urban civilization (11,000 years ago): Agriculture arrived quite late in the history of our species, but when it arrived -- i.e. at the end of the Wurm glaciation -- it arrived independently in four to eight different places around the world, in different biogeographic realms and climates, so I must assume that at least some climate regimes are great for it (glacial cycles are a minority of Earth's history; but did agriculture need to come after glaciations? Maybe a shock of seasonality did the trick). And once you have agriculture, complex urbanized societies follow most of the time, just a few millennia later. Even writing arose at least three times (Near East, China, and Mexico), and then spread quickly.

10. Scientific method and industrialization (300 years ago): We're getting too far from my expertise here, but whatever. The Eurasian Axial Age suggests that all civilizations with a certain degree of wealth, literacy, and interconnection will spawn a variety of philosophies. Philosophical schools that focus on material causes and effects like the Ionians or Charvaka have appeared sometimes, but often didn't win over more supernaturalist schools. Perhaps in pre-industrial times pure materialism isn't as useful! You may need to thread a needle between interconnected enough to exchange and combine ideas, and also decentralized enough that the intellectual elite can't quash heterodoxy. As for industrialization, that too happened only once, though that's another case in which the first achiever would snuff out any other. I hear Song China is a popular contender for alternative Industrial Revolutions (with coal-powered steelworks!); Imperial Rome and the Abbasid Caliphate are less convincing ones. For whatever reason, it didn't take until 18th century Britain.

11. Not dying randomly along the way: Mass extinctions killing off a majority of species happened over and over -- the Permian Great Dying, the Chicxulub impact, the early Oxygen Crisis -- but life has always rebounded fairly quickly and effectively. It's hard enough to sterilize an agar plate, let alone a planet. Disasters on this scale are also unlikely to happen in the lifespan of planet-bound civilizations, unless of course the civilizations are causing them. A civilization might still face catastrophic climate change, mega-pandemics, and nuclear war, not to mention lesser setbacks like culture-wide stagnation or collapse, and I couldn't begin to estimate how common, or ruinous, they would actually be.

****

I have no idea how common the origin of life is, but the vast majority of planets with life will only have bacterial mats and stromatolites. Of the tiny sliver that evolved complex cells, a good chunk will have their equivalents of plants and animals, most of which may have intelligent life at least on primate- or cetacean-level at some later point. At any given time, a tiny fraction of those will have agricultural civilizations, at an even tinier fraction of that will have post-industrial science and technology. Let's say maybe 1 planet with industrial technology out of 100 with agriculture, 100,000 with hominid-level intelligence, 10 million with animal-like organisms, 100 millions with complex cells, and 10 billions with life at all?

[olive-ridley]

All roads lead to Rome, all lineages evolve to CRAB 🦀🦀

[druid-for-hire]

[image id: a four-page comic. it is titled "immortality” after the poem by clare harner (more popularly known as “do not stand at my grave and weep”). the first page shows paleontologists digging up fossils at a dig. it reads, “do not stand at my grave and weep. i am not there. i do not sleep.” page two features several prehistoric creatures living in the wild. not featured but notable, each have modern descendants: horses, cetaceans, horsetail plants, and crocodilians. it reads, “i am a thousand winds that blow. i am the diamond glints on snow. i am the sunlight on ripened grain. i am the gentle autumn rain.” the third page shows archaeopteryx in the treetops and the skies, then a modern museum-goer reading the placard on a fossil display. it reads, “when you awaken in the morning’s hush, i am the swift uplifting rush, of quiet birds in circled flight. i am the soft stars that shine at night. do not stand at my grave and cry.” the fourth page shows a chicken in a field. it reads, “i am not there. i did not die” / end id]

a comic i made in about 15 hours for my school’s comic anthology. the theme was “evolution”

[theartofmadeline]

i promise i wouldn't blame you

[samimarkart]

Grounded Flight

2024, decolorant screenprint on quilted cotton

[casualcarpetshark]

BOW DOWN TO THE ANCIENT ONE

[prokopetz]

If you've seen trivia posts going around, may have seen ones about the baculum, a bone in the penis whose purpose is to help support erections which is present in most placental mammals, including non-human apes, but which is conspicuously absent in humans.

Those posts typically don't go into why this is the case, which is fair enough, since the question is far from settled. However, there are a lot of hypotheses about it, and some of them are pretty fucking wild.

I think my personal favourite is the recently proposed idea that, since soft tissue injuries tend to heal more rapidly and completely than broken bones, a flexible and resilient boneless penis constitutes a reproductive advantage in situations where genital trauma is common, possibly as a result of the development of upright posture rendering the penis more prone to blunt encounters.

Like, imagine humanity's proto-hominid ancestors going "actually, bipedalism is great" and promptly getting whacked in the ding so much that it exerted evolutionary pressure on the morphology of the penis.

[scentedwonderlandpoetry]

Further new discoveries have been made on my theory.

[todaysbird]

Thank you Grandpa Iridescence…

[console-pokeballs-rupees]

fantasizing about evolution by フキダシコットン on X

[amnhnyc]

What can we learn from a dinosaur feather preserved in amber? Let’s go behind the scenes of the Museum’s collection of amber fossils to find out!