7 ms·

You're either talking about formation of the gut tube (gastrulation) or the formation of the neural tube after that (neurulation).

prawn 6y ago
For anyone familiar with these things, is their significance that they create tubes which are isolated systems?
- Balgair 6y ago
  I'm confused as to your question. What is the 'their' in the second part of your sentence? Generally, in development, it's the lineage of the cells that matters the most. Skin and neuronal cells have a closer lineage than the gut cells do.
  - prawn 6y ago
    The initial result of the gastrulation and neurulation. e.g., what would've made that process 'useful' so that it persisted in an evolutionary sense. Would intestinal processes work as well if they weren't contained (from mouth to anus), or if brain/spine/nerve channels weren't separated from other parts of the body.
    - Balgair 6y ago
      I think I get the question. Neural tube-like structures are pretty ancient. Hallucigenia, I believe, is the oldest fossil (-0.5 BYA) that shows the differentiation of a single neural tube-like structure [0], right back to the mid-Cambrian Explosion. We are the ancestors, likely, of that animal. It seems that bi-lateral symmetry is a highly advantageous body plan, as it's evolved a few times in separate clades that weren't that before. As to the reason why bilateral symmetry is good, it's a good question! As for the difference in why neural tubes are better, it seems that the ability to centralize the information exchange between the body and (what may pass for a) brain is a better fit with a single trunk. Other animals do have other arrangements, but the one we have has the most diversity of subsequent animals forms. It seems to be a more flexible arrangement and evolution seems to have preferred it. Granted, the neural tube idea has been through a few mass extinction events, so there is a considerable amount of luck involved too. [0] For reference, the reason that arachnids are different than other 'insects' is because they have dual ganglia structures that run down the rostral(head)-ventral(tail) axis instead of a single neural tube. That divergence took place before Hallucigenia, I believe.
      - prawn 6y ago
        That's all really interesting. Thank you!
- 1auralynn 6y ago
  The neural tube is the predecessor to the spine. Gastrulation isn't really a tube formation more like layers forming, it's the initial differentiation of cells from uniform to specialized.

prawn 6y ago

For anyone familiar with these things, is their significance that they create tubes which are isolated systems?

Balgair 6y ago
I'm confused as to your question. What is the 'their' in the second part of your sentence? Generally, in development, it's the lineage of the cells that matters the most. Skin and neuronal cells have a closer lineage than the gut cells do.
- prawn 6y ago
  The initial result of the gastrulation and neurulation. e.g., what would've made that process 'useful' so that it persisted in an evolutionary sense. Would intestinal processes work as well if they weren't contained (from mouth to anus), or if brain/spine/nerve channels weren't separated from other parts of the body.
  - Balgair 6y ago
    I think I get the question. Neural tube-like structures are pretty ancient. Hallucigenia, I believe, is the oldest fossil (-0.5 BYA) that shows the differentiation of a single neural tube-like structure [0], right back to the mid-Cambrian Explosion. We are the ancestors, likely, of that animal. It seems that bi-lateral symmetry is a highly advantageous body plan, as it's evolved a few times in separate clades that weren't that before. As to the reason why bilateral symmetry is good, it's a good question! As for the difference in why neural tubes are better, it seems that the ability to centralize the information exchange between the body and (what may pass for a) brain is a better fit with a single trunk. Other animals do have other arrangements, but the one we have has the most diversity of subsequent animals forms. It seems to be a more flexible arrangement and evolution seems to have preferred it. Granted, the neural tube idea has been through a few mass extinction events, so there is a considerable amount of luck involved too. [0] For reference, the reason that arachnids are different than other 'insects' is because they have dual ganglia structures that run down the rostral(head)-ventral(tail) axis instead of a single neural tube. That divergence took place before Hallucigenia, I believe.
    - prawn 6y ago
      That's all really interesting. Thank you!
1auralynn 6y ago
The neural tube is the predecessor to the spine. Gastrulation isn't really a tube formation more like layers forming, it's the initial differentiation of cells from uniform to specialized.