Can you guys please not take the bait by posting unsubstantive comments? We've changed the silly title (edit: I meant the article's own linkbaity title) to a more interesting sentence from the article body.
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Crabs evolved at least five times from separate groups of crustaceans (2021)
41–50 of 138 posts
Re: Crabs evolved at least five times from separate groups of crustaceans (2021)
#42Ive 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?
but every species had arisen from sea
Re: Crabs evolved at least five times from separate groups of crustaceans (2021)
#43Even more wild to me is that saber-toothed cat-like predators evolved seven separate times: https://en.wikipedia.org/wiki/Saber-toothed_predator
There was a recent article on here about how species that looked alike were not necessarily related and is was more common to have physically dissimilar but geographically close species that were evolutionary relatives. One of the points was that convergent evolution was more common than people thought. These stories appear to support the convergent evolution assertion
Re: Crabs evolved at least five times from separate groups of crustaceans (2021)
#44Earlier quoted context omitted.
Quoted post unavailable.
“Selection” is a very easily misunderstood technical term which overlaps with concepts people often find more familiar. “Natural” is basically whatever anyone wants it to mean. Without intentional study, basic foundations of evolutionary biology are easily misinterpreted. To the extent I can give you the benefit of the doubt that you’re an outlier and understand it better… you’re an outlier. Not the people who you’re…
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]
Re: Crabs evolved at least five times from separate groups of crustaceans (2021)
#45Earlier quoted context omitted.
> misunderstanding of their culture Maybe it’s just your culture?
This reminds me of ESR's Jargon File, which kept defining "hackers" as liking or doing things when it was actually just him.
I forget it’s history, but the jargon file predates esr. Check levy’s heroes of the computer revolution about the original mit hackers.
Re: Crabs evolved at least five times from separate groups of crustaceans (2021)
#46Earlier quoted context omitted.
“Selection” is a very easily misunderstood technical term which overlaps with concepts people often find more familiar. “Natural” is basically whatever anyone wants it to mean. Without intentional study, basic foundations of evolutionary biology are easily misinterpreted. To the extent I can give you the benefit of the doubt that you’re an outlier and understand it better… you’re an outlier. Not the people who you’re…
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 why were dinosaurs stronger than me?"
Re: Crabs evolved at least five times from separate groups of crustaceans (2021)
#47Ive 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 evolutionary picture of the whales can be broken down as follows:
- 3.8 billion years ago: The first single-celled organisms appeared (Bacteria)
- 3 billion years ago: Viruses (also single-celled organisms) became present
- 2 billion years ago: Eukaryotic cells are present. These are cells that contain organelles, or tiny organ-like structures
- 1.5 billion years ago: Eukaryotic cells evolved three ways. These cells evolved into the ancestors of plants, animals, and fungi
- 900 million years ago: The first multicellular structures became present
- 800 million years ago: The animal strain of organisms undergoes its first split and continues into basic marine organisms such as sponges
- 540 million years ago: The first chordates or animals with backbones are present
- 530 million years ago: The first true vertebrate or boned organism is present
- 500 million years ago: Animals first started exploring the land
- 417 million years ago: Lungfish became present. Lungfish are the first organisms to breathe both on land and in the water with both lungs and gills
- 397 million years ago: The first tetrapods or four-legged species are present
- 340 million years ago: Amphibians branch off from the other tetrapods
- 310 million years ago: The remaining tetrapods split into what will be reptiles, birds and dinosaurs, and mammals
- 200 million years ago: A mass extinction occurred and warm-blooded proto-mammals developed
- 140 million years ago: Placental mammals also known as eutherians are present
- 105-85 million years ago: The placental mammals split into four major groups, including laurasiatheres, which will contain the whale species.
- 65 million years ago: The greatest extinction event so far wipes out the dinosaurs providing more potential for mammals to colonize the planet
- 50 million years ago: Artiodactyls pakicitus, a mammal, resembling a wolf and tapir mix with cloven hooves begins evolving into what we know as whales
- 47 million years ago: Early forms of whales live in shallow seas, returning to land to mate and give birth
- 35-45 million years ago: The first fully aquatic whale is present (Basilosaurus)
Modern-day whales are believed to have moved into the oceans around the Tethys Sea, now the Mediterranean Sea and Asia.
Re: Crabs evolved at least five times from separate groups of crustaceans (2021)
#48Ive 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?
Re: Crabs evolved at least five times from separate groups of crustaceans (2021)
#49Earlier quoted context omitted.
“Selection” is a very easily misunderstood technical term which overlaps with concepts people often find more familiar. “Natural” is basically whatever anyone wants it to mean. Without intentional study, basic foundations of evolutionary biology are easily misinterpreted. To the extent I can give you the benefit of the doubt that you’re an outlier and understand it better… you’re an outlier. Not the people who you’re…
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 misinterpreted or misappropriated.
Re: Crabs evolved at least five times from separate groups of crustaceans (2021)
#50Eons did a great piece on this recently: https://youtu.be/wvfR3XLXPvw One of the things I love about the way Eons cover topics is how they don't just focus on what we know, but also how we know, who figured things out, and what we got wrong along the way. Can't endorse their style of science journalism enough.
PBS has been putting out such great content in the last 5 years. Really impressive and highly overlooked
PBS space time is another good channel. Their series on general theory of relativity is really nice. They try to explain it as close as possible to the real thing but still make it accessible without resorting to innacurate analogies