The Temple of Dagon

As far as I remember, in 'The Shadow Over Innsmouth', Lovecraft never really explains what actually causes the "Innsmouth Look" (besides speculating at a disease of some kind). I was just curious if any of the Mythos stories since have explained it in any more detail? Is it something that just happens once you start to worship Dagon or whatever, or do the Deep Ones actually do something to make them start to change (such as disease infection)?

i thought it was an inherited trait.. if one of your parents is a deep one, you will start to look fishier as you age, and eventually you end your human life and emigrate to y'ha-nthlei at the bottom of devil's reef.

do regular humans turn into deep ones too? i don't know

Yep, hybrid spawn. And no, they look like regular humans to begin with - cf/ the narrator of "Shadow..." - but slowly turn. In my opinion, that was a terrible way to end the story, I'd much rather have done it another way.

What other deep one cities still exist? I heard there was around four left

So there's no way for a regular human to turn then? It's purely genetic?

Yah its genetic, I think in The Shadow over Innsmouth, it said that captain Marsh who originally made all the deals with the Deep Ones dies of old age...his kids were Deep Ones though, seeing as he took the Oath of Dagon

Yeah, it's genetic but as with any hybrid population you can think of (examples please...!) there is variation as to how the deep one phenotypes are expressed.

It's hinted that there is some kind of selective breeding program going on with the cult of dagon, but I'm not sure weather I get that from the Lovecraft story or from the spin off mythos stories/films/games...

The Deep ones have dominant genes, so the human recessive chromosomes begin to brake down during old age, thus being replaced with Deep one DNA...doesnt make much sence but wtf you want right?

Marquis Wheat is a hybrid...God knows where we'd be without it!

Given that every child contains 23 chromosomes from each parent, the first generation hybrids will be 50% each human and deep one. I assume one of the oaths taken is to ensure that a sufficient level of deep one-age is kept in the family - perhaps mating a hybrid with a purestrain to get something anywhere between 50-100% deep one, or keeping the hybrids together, which has equal chances of spawning a normal human or a purestrain deep one, with everything in the middle being an option, too. I also would guess that anything not considered deep one-ish enough is killed at birth - they can probably sense their own.

Idk maybe there needs to be one generation of Human/Deepone hybrids before they themselves can produce anything close to a deepone...the resulting offspring would be from 75-99% Deep One

Nah, two hybrids could birth a purestrain Deep One. The odds are about 1/70368744177664, though.

yah I dont think the odds are that good, it would be a better chance that it at least seems like a Deep One...There would still be a good bit of human in there...perhaps even...Love?

Those, by the way, are also the odds of it being a normal human.
If the hybrids breed and create more hybrid spawn with a greater number of Deep One chromosomes, the odds of birthing a purestrain go up exponentially.

Man, think about how aquard it would be if two almost entirely Deep Ones gave birth to a pure strain human...Imagine the crazy antics