modeler

Just to add - Thai has a tonal system and distinguishes rising, low, medium, high and falling tones. This requires a bit more time to say so that there is time for the tone to change (or not change).

Some languages have fewer vowel sounds while others have an insane number (in Europe that would be Danish).

Thai has a lot, so speakers need to speak more slowly so the listener has time to distinguish words. But it also means that you can have more words per syllable.

It's not about efficiency per se - it's data and error correction

I'm a bit of an OCD logic nerd. When I eat something, I need to immediately gulp down another 7 otherwise I could never have ate them.

Maybe it was the Black Prince who was blind?

I think he's beginning to realise that some of the sovcit personalities haven't actually won anything in court, but still thinks that sovcit is a real thing. So he's trying to filter out the bullshitters and talk directly to a sovcit who succeeded. He's going in the roght direction but has already made a series of decisions that will haunt him to the end of his life.

There's a word for not being able to handle this: misophonia

It seems that for some people (myself included) it generates a primal urge.

Or stepping off an escalator and just stopping right there to get their bearings.

Some rules weaken, and others are created or subtly change - that's why parents can never get their kids' slang quite right. It's not that the parents can't simply weaken their grammar, it's that the kids do some things differently with very strict rules.

Thank you for writing 'a lot' and not 'alot'.

I see that alot.

^ ^ ^ ^ that's my trigger

So do I understand correctly that a certain hox gene is activated in basically all cells which are in the "domain" of a certain vertebrae

Yes

and they all activate some subset of homeobox genes which in combination with the original hox gene cause them to start turning into all the different parts associated with that vertebrae (so organs and other structures)?

Not quite. The hox gene creates a protein that tells the nearby cells that they are in a specific segment. After this specific cells in that segment start signalling so they cooperatively lay out the cardinal directions to make that specific segment. In the shoulder segment, for example, a specific cell becomes the tip of the arm and tells all the cells about it with its signalling protein. All the cells in between it and the root now 'know' which part of the arm to grow.

This is a cascade of ever finer positioned 'location markers' that guide generic cells to specialise correctly.

Ultimately, as two bones grow into each other, they know to form a joint, and as that joint takes form the joint surfaces fit each other exactly.

Would we then need an entirely new hox gene to produce even a single gill? (I know you basically just laid out most of a response to this question.) Because I would assume although the exact point at which the development of our arms and legs begins is part of the whole hox gene "superstructure", but couldn't we 'basically just' highjack this same system and duplicate this gene to produce at least a single gill in the region where the current hox gene for our neck is expressed?

Assuming we want to keep our neck, jaw and ear features, we need to keep our existing hox gene and all the genes that turn on in this cascade to produce these structure. If we alter them, our development will change.

The issue is that in a fish or shark, exactly the same location marker is used to lay down their gills. So adding a shark hox gene will result in a human segment at that location. Hox is a marker - not the full set of instructions to build the segment.

We therefore need

1. A new location marker for the gill
2. And we need our developing cells to recognise this new signal
3. And we need a development pathway to create a gill which includes new location markers, and the ability for cells to differentiate in the right place to new tissues
4. New genes for specific proteins to create these new tissues (which may be copyable from other organisms)

Long story short: what is the biggest reason why we can't just hack into a later part of the sequence and continue on from there with what you said?

Well, we can't reuse the existing one because it creates human structure. So we need brand new genes for 2 and 3.

I'm not a professional in this area, but I haven't seen anything that suggests we can fo this yet.

I think part 4 (the bit about creating new tissues) might in fact be the easier part. But to cause them to be developed at the right time in the right place and at the correct size with brand new signals is waaaay out there.

Or would your proposed plan also just end up like this in the final product and you laid it out like this because it's already the most viable route into this mess? 😅

Speaking as someone whose last practical biology wiped out all the very expensive cell colonies, and that was 30 years ago, I hope my wild suggestions here are even vaguely in the right direction.

In a way, your jaw is a gill arch, just built in a different way with some interesting diversions. After a couple of 100 million years, the changes do add up.

If you really had to add in a gill, i have a plan, but I need to talk about one important evolutionary trick: duplication and divergence.

A fairly common DNA copying error causes a section of a chromosome to be duplicated in the offpring. In most cases this is fatal or prevents children, but some duplications work out just fine.

For instance mammals lost colour vision in the time of the dinosaurs - mammals were probably nocturnal. The loss was caused by losing genes for the yellow colour receptors in the eye. This is why dogs and cats see in something akin to black and white (they do see red and blue and all the yellows and greens are just shades of red and blue).

But apes were lucky. An accident duplicated the existant red receptor and, over time, because there are now two genes, one gene was gradually selected for a higher and higher light frequency. This has become our green receptor and all apes see in red-green-blue colour.

Duplication is not necessarily fatal because it just codes for something we already have. But once there are 2 genes, evolution can select away for different capabilities and we end up with something new.

Ok, with that out the way let's plan!

1. Add in a few new sections into the human body by adding some new hox genes. This would give us a significantly longer neck - probably fatal without medical support.
2. Duplicate and diverge the genes used to trigger gill arch/neck and jaw development and modify the developmental genes that respond to them. This would preserve the development the upper neck as humans (to keep the jaw and ear) while allowing something else to happen lower down
3. In the lower section work out a way to develop like our basal forms (something eel-like) and trigger this development with the modified genes from step 2.

Step 1 might be possible today. Step 2 might be within current reach (but it would take incredible work to disentangle all the connected system in development and the working body. Step 3 is beyond current tech (as I understand).