Fossils reveal anacondas have been giants for over 12 million years | Hacker News Reader

Fossils reveal anacondas have been giants for over 12 million years

cam.ac.uk

76 pointsashishgupta220943 comments

Study: https://www.tandfonline.com/doi/full/10.1080/02724634.2025.2...

Anacondas can & will eat anything that moves, that's a evolutionary feedback loop, but I hesitate to call it positive

Ah, so buns means movement.

It's commonly hoped that pet anacondas that have been with you all their lives should be more circumspect, but experts say otherwise

I'll never forget the Palo Anaconda scare. Update: it was a black mamba scare, oops https://www.paloaltoonline.com/news/2023/10/10/palo-alto-res...

I wonder why even looking at pictures of giant snakes is unsettling. And cockroaches too.

Cause your nervous system knows what a snake is but doesn't know what a picture is?

It is proven by science that there is no such thing as an intuitive fear of snakes. Its 100% cultural. Toddlers don't fear snakes for example.

Is culture how cats and cucumbers work?

No, that's how surprise works.

As in "Cop scared by mannequin":

https://youtu.be/xf1Y2En4fGE?si=2RwRnGBoGHuCNogG&t=416

What about spiders?

Reference?

https://pmc.ncbi.nlm.nih.gov/articles/PMC6716607/

I'm aligned with @iberator here.

I grew up with children and people in Northern Australia that had zero fear of snakes and spiders with plenty of exposure to both.

When I was 13 a friend of my sister, a large imposing Torres Strait Islander girl, visited and saw a cat for the very first time and screamed fit to break glass while jumping back to break the wall panel and up onto the couch.

This was someone comfortable handling large live mud crabs on the floor, gutting fish, handling snakes and killing them, etc.

I've always found this interesting because nothing about the appearance of a snake has ever bothered me, unsettled me, or made me fearful. They actually look very neat to me, and the tiny snakes I've had the fortune of holding were very fun to feel slithering about in my hands.

Cockroaches on the hand, not scary at all, but I feel disgusted by them.

And large spiders, extremely scary to me, instant fear response.

It's the exact same for me. The spiders are by far the most visceral fear response, especially if a gruesomely detailed photo pops up on my phone.

Smaller spiders scared me when I was younger, but I have overcome that phobia significantly. Large, hairy, distinctly arthropodic spiders, though...? Yuck.

Question for both you and GPP; is this fear limited to real life depictions, or basically anything? E.g, if you ever played Skyrim or a game with spider-like enemies does it have the same effect as a real spider?

Answers I've seen to this question tend to vary wildly.

I'm also really afraid of snakes, but spiders are okay. Movies with snakes are quite painful to watch too, and I'm very uncomfortable with snakes in video games, but at least I have some control (compared to TV) so it's a significantly better experience

Spider-fear has never been triggered by fictional spiders for me. Very few works ever bother getting the face and body right though. 8 legs alone are not scary for me, the fangs and eyes and color patterns and the sneaky movement and webs are scary.

I'm not terribly afraid of real spiders though. Hairy crawling spiders like wolf spiders and tarantulas don't really bother me at all. It's the ones with the big web-spinning butts that dangle and drop down from above that make me go straight into fight-or-flight.

I did play Skyrim, and I was fine with it. Something about video games takes the fear out of it. I mean, they're definitely a little bit more unsettling than other video game creatures, but not by much, so I don't get a fear response. I'd react more to a "jump scare" in a game than a 3D spider.

It’s weird that I’m the opposite. Spiders of any size have absolutely no effect on me. But snakes trigger some sort of innate response. I wonder if it’s tied to geographic origins of our ancestors?

I have no idea. I do not fear any of them, but I would fear some in real life were they near me, but only because I know they might be able to kill me.

Cockroaches are just, like someone else said, disgusting to me, especially if they are at home. If they are outside I could not be bothered.

I'd guess it's due to some kind of imprinting during childhood, similar to taste. The widespread prevalence of irrational phobias and methods for curing them certainly suggest to my untrained eye a learned behavior rather than innate.

I have all the same responses as you, heh. Centipedes also give me that instant creepy-crawly feeling.

And when I see a cockroach fly the disgust is multiplied by like ten.

https://www.youtube.com/watch?v=O_RpgSKxjwk

Interesting watch about what babies fear.

I believe that things like fear of needles is something passed on from parents.

I'm not unsettled by them.

There is the theory that a substantive percentage of people have dangerous prenatal experiences with their umbilical chord, as the source of their fear of snakes, and that it can be resolved later in life with regressive therapy. See e.g. ”Womb Surround” by Ray Castellino.

Wouldn't those people also be afraid of ropes, cables, etc?

I think the idea is that an umbilical cord is experienced as “alive” whereas ropes are just “dead items”, something that in early years may trigger the original fear responses but gets integrated more easily.

> Global changes have since driven many other giant animals to extinction, but anacondas grow just as big today.

But why? Why have anacondas - and sharks? - been immune to evolving? Why hasn’t a significant predator evolved - or invaded? - to feed on them? Why hasn’t 12 million years made the species fragile?

They've reached a local maximum.

This comment seems to be generating downvotes, but I find the questions fascinating. It is a stretch to say the fossil record rules out any evolutionary changes to anacondas. However, if anacondas represent another form of so-called "living fossils" [0], it is interesting to think about what makes them resistant to the change that seems to occur as a matter of course in many other organisms?

0. https://en.wikipedia.org/wiki/Living_fossil

It was my comment. Thanks, cause I see plenty of NH treads that go completely off topic and there are too few down votes for that.

In any case, 12M years a long time for a species to survive, let alone survive “as is”. It makes me think of the creature in Alien and how it evolved into deadly perfection. But these creatures aren’t fictional.

p.s. Aren’t octopuses another species of little to no change? But they’re weird anyway so it’s not a surprise?

Octopuses are all soft tissue (except for their "beak"), so it would be very hard to determine from the fossil record how much change has occurred. Perhaps as a result, they are not mentioned in the "living fossil" article above.

An additional complication is that some cephalopods have a relatively unique ability to change gene expression in response to environmental factors [0]. As a result, even if one were to see physiological change or change in ecological niche, it might not be as a result of speciation.

Hopefuly soon techniques of analyzing ancient DNA [1] will be more broadly used to understand the stories of long surviving species.

0. https://www.nsf.gov/news/masters-acclimation-octopuses-adjus...

1. https://en.wikipedia.org/wiki/Ancient_DNA

We can't observe these ancient snakes or sharks actually living, so we can only make assumptions based on their morphology. And morphology certainly constraints and suggests behavior, and so we can make some assumptions here.

That being said if the question is "why have we not seen significant morphological changes" - there are a few ways to think about this.

First is that we would be blind to many types of morphological evolution. For example, if an isolated sub population of snakes or sharks started shrinking due to isolated environmental pressures, we would be unlikely to see this, but also if we fixate on the "largest anaconda", then we would filter out all "smaller snakes".

Second, the way we talk about "not evolving", especially for sharks is probably misleading. When we say sharks haven't changed, we mean to say that the shark body plan hasn't significantly changed. And this makes sense - they have a very efficient body plan for being a hunter in the see. We have "proof" of the suitable-ness since dolphins and other whales have converged onto a very similar body plan. Conversely, there are plenty of extinct sharks with body features that seem totally bizarre (https://www.fieldmuseum.org/blog/four-fossil-sharks-are-cool...).

Finally, especially in the context of "the largest" - the largest animals that can exist in a given environment is.... environmentally constrained, especially for land animals. The largest anaconda is likely near the largest sizes that the local environment to support, and so something larger appear is unlikely, without drastic environmental changes.

Why hasn’t anything evolved to prey on them? Given all the calories they could provide.

"Error 403 Forbidden"

I guess that's this new UK laws in effect? How can I prove I'm old enough to watch some giant snakes? :)

There is no age gating on this content.

Some sites geoblock the UK because of our less than sensible laws e.g. imgur.

I'm not even from the UK (EU here).

The following is what I'm seeing exactly, and because it still happens it seems deliberate, not a temporary issue where I was "snake-joking" about earlier. Well… no cute snakes for me.

--- Error 403 Forbidden

Forbidden Error 54113

Details: cache-fra-etou8220097-FRA 1765473610 1384447547

Varnish cache server

Cambridge source: https://www.cam.ac.uk/stories/twelve-million-years-of-giant-...

Thanks, we updated the link.

At last, something that isn't about python!

anaconda is a package manager for python

sorry ...

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