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"The sea squirt larvae begin absorbing all the tadpole-like parts that made them chordates. Where the sea squirt larva once had gills, it develops the intake an

"The sea squirt larvae begin absorbing all the tadpole-like parts that made them chordates. Where the sea squirt larva once had gills, it develops the intake and exist siphons that will help it bring water and food into its body. It absorbs its twitching tail. It absorbs its primitive eye and its spine-like notocord. Finally, it even absorbs the rudimentary little "brain" (cerebral ganglion) that it used to swim about and find its attachment place." By that measure, I suppose a caterpillar also "eats its own brain" during its transformation in to a butterfly.

wyattpeak 6y ago
It may be overstated for effect (which the author acknowledges), but it's a little more dramatic than a caterpillar in that it ends up without a brain, while a butterfly doesn't. I also don't think current thinking holds that the organs of a caterpillar disappear completely during metamorphosis, though I could easily be wrong.
- pmoriarty 6y ago
  One of my favorite Radiolab episodes[1] was about just this: MOLLY: What do you think happens inside the chrysalis? JAD: I think that -- I actually have never thought about it, to be honest. MUSEUM GUEST: I don't know. I don't -- I don't understand how it works. MOLLY: Not many people have. MOLLY: Are you, like, surprised that you actually don't know? MUSEUM GUEST: Yeah, I'm surprised. I thought, like, I knew and I don't. MOLLY: Those are folks I met at the museum. JAD: Hey, hold up. Now that I've thought about it for a second, isn't it simply that the caterpillar is inside the shell, it sort of snuggles up, and then it grows a wing off of its right side and then off of its left side, and it just pops wings out? MOLLY: No. That is actually what I thought, but that's not right at all... [1] - https://www.podtrac.com/pts/redirect.mp3/audio.wnyc.org/radiolab/radiolab011714c.mp3 https://www.podtrac.com/pts/redirect.mp3/audio.wnyc.org/radi...
- MacsHeadroom 6y ago
  A caterpillar becomes a soup of cells, fats, and proteins. Some species do not retain any multi-cellular structures- others only a tiny few. Interestingly, the still exhibit learned avoidance behaviors after complete this near complete disassembly and reassembly.
  - wyattpeak 6y ago
    Are you an expert? If so I defer, but if not I think you're repeating an old understanding of the process. From a bit more reading a substantial portion seems to dissolve, but far from everything. Here's a paper tracking the metamorphosis of painted lady butterflies in considerable detail: https://royalsocietypublishing.org/doi/10.1098/rsif.2013.0304 https://royalsocietypublishing.org/doi/10.1098/rsif.2013.030...
    - solipsism 6y ago
      Are you an expert? If so I defer Don't. An expert is the person most likely to be able to provide good support for their claims.
      - Zuider 6y ago
        I agree. The stance "I defer to the experts" is potentially very damaging to the growth of knowledge, and can quickly lead to what philosopher of science, Imre Lakatos, called a 'degenerative paradigm,' where increasingly elevated credentials represent increasingly less actual skill and knowledge. While credentials perform a necessary function, they are a placeholder, an IOU, and not themselves final grounds to accept a claim. They ought not to be treated as a primary source, and a claim based on a bare assertion of expertise should be accepted provisionally and only on the understanding that support can, in fact, be provided if the matter is pressed. In short, your definition is a pretty good one.
        wyattpeak 6y ago
        I can see the argument for it, but I think that, especially at present, more harm is being done by a belief that expert opinion should be subject to obsessive outside scrutiny (by whom?) than this fairly academic concern about damaging the growth of knowledge. For all that people like to point out the conservativeness of past experts rejecting ideas ultimately proven correct, few like to engage with the fact that almost all of those ideas were ultimately championed from within the establishment, not by radical outsiders.
ncmncm 6y ago
Absolutely not! The nervous system is retained intact.

wyattpeak 6y ago

It may be overstated for effect (which the author acknowledges), but it's a little more dramatic than a caterpillar in that it ends up without a brain, while a butterfly doesn't. I also don't think current thinking holds that the organs of a caterpillar disappear completely during metamorphosis, though I could easily be wrong.

pmoriarty 6y ago
One of my favorite Radiolab episodes[1] was about just this: MOLLY: What do you think happens inside the chrysalis? JAD: I think that -- I actually have never thought about it, to be honest. MUSEUM GUEST: I don't know. I don't -- I don't understand how it works. MOLLY: Not many people have. MOLLY: Are you, like, surprised that you actually don't know? MUSEUM GUEST: Yeah, I'm surprised. I thought, like, I knew and I don't. MOLLY: Those are folks I met at the museum. JAD: Hey, hold up. Now that I've thought about it for a second, isn't it simply that the caterpillar is inside the shell, it sort of snuggles up, and then it grows a wing off of its right side and then off of its left side, and it just pops wings out? MOLLY: No. That is actually what I thought, but that's not right at all... [1] - https://www.podtrac.com/pts/redirect.mp3/audio.wnyc.org/radiolab/radiolab011714c.mp3 https://www.podtrac.com/pts/redirect.mp3/audio.wnyc.org/radi...
MacsHeadroom 6y ago
A caterpillar becomes a soup of cells, fats, and proteins. Some species do not retain any multi-cellular structures- others only a tiny few. Interestingly, the still exhibit learned avoidance behaviors after complete this near complete disassembly and reassembly.
- wyattpeak 6y ago
  Are you an expert? If so I defer, but if not I think you're repeating an old understanding of the process. From a bit more reading a substantial portion seems to dissolve, but far from everything. Here's a paper tracking the metamorphosis of painted lady butterflies in considerable detail: https://royalsocietypublishing.org/doi/10.1098/rsif.2013.0304 https://royalsocietypublishing.org/doi/10.1098/rsif.2013.030...
  - solipsism 6y ago
    Are you an expert? If so I defer Don't. An expert is the person most likely to be able to provide good support for their claims.
    - Zuider 6y ago
      I agree. The stance "I defer to the experts" is potentially very damaging to the growth of knowledge, and can quickly lead to what philosopher of science, Imre Lakatos, called a 'degenerative paradigm,' where increasingly elevated credentials represent increasingly less actual skill and knowledge. While credentials perform a necessary function, they are a placeholder, an IOU, and not themselves final grounds to accept a claim. They ought not to be treated as a primary source, and a claim based on a bare assertion of expertise should be accepted provisionally and only on the understanding that support can, in fact, be provided if the matter is pressed. In short, your definition is a pretty good one.
      - wyattpeak 6y ago
        I can see the argument for it, but I think that, especially at present, more harm is being done by a belief that expert opinion should be subject to obsessive outside scrutiny (by whom?) than this fairly academic concern about damaging the growth of knowledge. For all that people like to point out the conservativeness of past experts rejecting ideas ultimately proven correct, few like to engage with the fact that almost all of those ideas were ultimately championed from within the establishment, not by radical outsiders.

ncmncm 6y ago

Absolutely not! The nervous system is retained intact.