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Crabs evolved at least five times from separate groups of crustaceans (2021)

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Re: Crabs evolved at least five times from separate groups of crustaceans (2021)

#51

Post by irrational »

vimy wrote: post #47
pratik661 wrote: post #37

Ive always wondered this: has a species have an evolutionary history where they originated in land but adapted to living in water and then adapted to living on land again?

Not exactly what you’re asking but whales used to be land mammals. > It is believed that modern-day whales evolved from land-based animals about 55 million years ago. These land-based mammals are believed to be hoofed mammals, sharing a common ancestry with even-toed ungulates such as the cow and the deer. > Evolution of Whales Whales started their journey as all other organisms have, as single-celled bacteria. An ev…

Which one of these was also the common ancestor of the hippopotamus?

Re: Crabs evolved at least five times from separate groups of crustaceans (2021)

#52

Post by eyelidlessness »

robonerd wrote: post #46
Geee wrote: post #44

Earlier quoted context omitted.

I mean just the basic concept of survival of the fittest, which doesn't require deep understanding of biology. The same concept also applies to lots of things besides biological evolution.[0] [0] https://en.wikipedia.org/wiki/Universal_Darwinism

> I mean just the basic concept of survival of the fittest, which doesn't require deep understanding of biology. Even that can be tricky for some people, since it requires people to think about fitness in a holistic way. But laypeople are culturally primed to think of athleticism. When talking to people skeptical of evolution, this sort of confusion comes up a lot. A lot of "If evolution makes things stronger then wh…

This. And, still biological, “why have some places selected for greater disability like deafness, or seeming disadvantages like below average height?” I don’t want to give too much weight to the “universal” concept, but it’s easy to imagine similar questions about why certain pockets of culture are places where seemingly disadvantaged traits thrive.

“Fit” is probably something better explained literally for an introduction, as in fitting a particular set of circumstances. But that’s really complicated and not something everyone grasps when the language is almost always surrounded by superlatives.

Re: Crabs evolved at least five times from separate groups of crustaceans (2021)

#53

Post by bombcar »

samatman wrote: post #15

Even more wild to me is that saber-toothed cat-like predators evolved seven separate times: https://en.wikipedia.org/wiki/Saber-toothed_predator

Someone keeps submitting the “saber tooth” product and it keeps getting rejected - no market fit?

Re: Crabs evolved at least five times from separate groups of crustaceans (2021)

#54

Post by alluro2 »

AlbertCory wrote: post #16

> We know the process has occurred multiple times and our current grant is aimed at better understanding the drivers and implications What can they actually discover? 10 legs good? But how about 12? [1] > The crab with the longest legs is the Japanese spider crab. It’s not related to spiders, despite its name. When extended, its legs can be as long as 12 feet. Now there's a nightmare for you. [1] https://www.referenc…

Oh that's some nightmare fuel all right: https://en.m.wikipedia.org/wiki/Japanese_spider_crab#/media/...

Re: Crabs evolved at least five times from separate groups of crustaceans (2021)

#55

Post by Geee »

eyelidlessness wrote: post #49
Geee wrote: post #44

Earlier quoted context omitted.

I mean just the basic concept of survival of the fittest, which doesn't require deep understanding of biology. The same concept also applies to lots of things besides biological evolution.[0] [0] https://en.wikipedia.org/wiki/Universal_Darwinism

“Survival” and “fitness” are just as commonly misunderstood for overlapping lay concepts. The concept of “survival of the fittest”, as expressed by Darwin, is a technical term I don’t expect most people to grasp. I question some of the well educated interpretations in the article you linked. In particular “fittest” seems to be the most challenging for people to understand, and the most vulnerable to being misinterpre…

I'd never guess that those specific words would be an obstacle for understanding the concept. Biological evolution is usually taught by explaining random mutation and reproduction, and that surviving mutations are passed on to the next generations. From there it should be quite intuitive to understand how it works as a basic concept.

Re: Crabs evolved at least five times from separate groups of crustaceans (2021)

#56

Post by bombcar »

krapp wrote: post #39
jleyank wrote: post #30

Earlier quoted context omitted.

Yeah, I would say I come from the ancient hacker culture. Don't be too critical of that, as RMS and the GPL are full derivatives of that culture. And the products of the GPL have been sorta useful to the HN community. Or at least the programming side. The others were there back then, but they weren't interest in hacking, just in counting.

Unfortunately, the hacker culture that gave rise to HN is a different beast altogether, and the crab mentality is strong here.

The cultures keep evolving crab mentalities independently.

Re: Crabs evolved at least five times from separate groups of crustaceans (2021)

#57

Post by photochemsyn »

irrational wrote: post #51
vimy wrote: post #47

Earlier quoted context omitted.

Not exactly what you’re asking but whales used to be land mammals. > It is believed that modern-day whales evolved from land-based animals about 55 million years ago. These land-based mammals are believed to be hoofed mammals, sharing a common ancestry with even-toed ungulates such as the cow and the deer. > Evolution of Whales Whales started their journey as all other organisms have, as single-celled bacteria. An ev…

Which one of these was also the common ancestor of the hippopotamus?

It's interesting to look at the primary literature, because then you realize how hard it is to sort these questions out and how many uncertainties there are, because there are a lot of different extinct lineages that might or might not have led to whales or hippos.

Here's the general group people seem to be fairly sure led to hippos; the ones that led to whales might have been an earlier group that gave rise to this group, or perhaps one of these, or perhaps not all whales share a 'root whale':

https://animals.fandom.com/wiki/Anthracotheriidae

The actual kind of data they use to make these judgements is mostly bone fragments from fossils, as comparing modern DNA of hippos and whales can only tell you so much. Here's an example study from 2003 on the hippo lineage:

https://wp.ufpel.edu.br/cdrehmer/files/2017/06/hipopotamo-ST...

Re: Crabs evolved at least five times from separate groups of crustaceans (2021)

#58

Post by asfarley »

alanbernstein wrote: post #48
pratik661 wrote: post #37

Ive always wondered this: has a species have an evolutionary history where they originated in land but adapted to living in water and then adapted to living on land again?

So there are 0) aquatic animals, 1) land animals (evolved from 0), and 2) aquatic mammals (evolved from 1). You want to know if there are e.g. 3) land animals that evolved from aquatic mammals? Not that it isn't an interesting question, but what exactly would this tell us?

It might suggest the existence of loops in the evolutionary tree, making it more of a general graph.

Re: Crabs evolved at least five times from separate groups of crustaceans (2021)

#59

Post by lmz »

alluro2 wrote: post #54
AlbertCory wrote: post #16

> We know the process has occurred multiple times and our current grant is aimed at better understanding the drivers and implications What can they actually discover? 10 legs good? But how about 12? [1] > The crab with the longest legs is the Japanese spider crab. It’s not related to spiders, despite its name. When extended, its legs can be as long as 12 feet. Now there's a nightmare for you. [1] https://www.referenc…

Oh that's some nightmare fuel all right: https://en.m.wikipedia.org/wiki/Japanese_spider_crab#/media/...

Long legs can't save it from Japanese cooking shows http://ironcheffans.com/?p=1573

Re: Crabs evolved at least five times from separate groups of crustaceans (2021)

#60

Post by grp000 »

bombcar wrote: post #53
samatman wrote: post #15

Even more wild to me is that saber-toothed cat-like predators evolved seven separate times: https://en.wikipedia.org/wiki/Saber-toothed_predator

Someone keeps submitting the “saber tooth” product and it keeps getting rejected - no market fit?

But the idea is just too cool to die.
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