A Question of the biologists in the group

[AndreaV]

Okay working on a minor human race. Ancient Bob is tinkering with his favourite human race (the bobites as he calls them) and decided they are far far too prone to nasty random genetic mutations and thus undoing all his lovely artistic genetic mutations. He studies the problem and decides it is due to their XY chromosome system, and the Y chromosome in particular. Therefore he decided to do away with said Y chromosome and instead have everyone with two X chromosomes, with gender being set by a genetic switch on the chromosome which can be either 'on' or 'off.' When the two switches agree (on/on or off/off) you get a girl, when they disagree (on/off) you get a boy.

So my questions
a) will this work at all?
b) will it be less prone to mutation?
c) presumably it results in a new species (Homo bob)?
d) is there any possibility of residual 'mule' level fertility with normal humans?

Thank you in advance

 

[Orr]

So my questions a) will this work at all?

Something somewhat like it already occurs in some species, so why not? The question now is what "flips the switch". In crocs it's the temperature at which the eggs were hatched.

b) will it be less prone to mutation?

No. The Y chromosome is the fastest evolving chromosome in the human genome. It mutation rate is due to it being housed in sperm which are produced by multiple cell divisions. Because one of your new X chromosomes is still going to be produced by males, that environmentally imposed mutation rate will still exist.

c) presumably it results in a new species (Homo bob)?

That would be your call.

d) is there any possibility of residual 'mule' level fertility with normal humans?

Again, your call. You have partial fertility with Homo bob males able to impregnate "normal" females but Homo bob females not able to concieve with normal males. Another twist would see Homo bob/normal crosses only be female.

 

[Fritz_Brown]

c) presumably it results in a new species (Homo bob)?

Not touching that with a ten foot po.... :smirk:

 

[sabredog]

Okay working on a minor human race. Ancient Bob is tinkering with his favourite human race (the bobites as he calls them) and decided they are far far too prone to nasty random genetic mutations and thus undoing all his lovely artistic genetic mutations. He studies the problem and decides it is due to their XY chromosome system, and the Y chromosome in particular. Therefore he decided to do away with said Y chromosome and instead have everyone with two X chromosomes, with gender being set by a genetic switch on the chromosome which can be either 'on' or 'off.' When the two switches agree (on/on or off/off) you get a girl, when they disagree (on/off) you get a boy.

So my questions
a) will this work at all?
b) will it be less prone to mutation?
c) presumably it results in a new species (Homo bob)?
d) is there any possibility of residual 'mule' level fertility with normal humans?

Thank you in advance

With the caveat in mind that we are talking about an Ancient developing his own experimental species in a science fiction role-playing game, I would have to say yes to all of the above. And that's despite a degree in biology (emphasis in evolutionary biology), but also understanding that a certain Descartes philosophical principal is at work in such a setting: if you can clearly imagine a thing within Traveller then it may exist in the reality contained within the game.

So go forth and imagine.