Vilani Genetics

[captainjack23]

If you read all of that and think I'm full of crap,

No way, dude....that was great. I was too chicken and lazy to point out the problems with the point mutation discussion. And, probably not as well spoken, either.

So. Biology ? Genomics ? Me: Stanford Genome Center. Biostatistics. HGP (non Ventner part)

(yes, this is the equivilent of the ex forces types comparing time at fort dix....)

 

[subunit]

If you read all of that and think I'm full of crap,

No way, dude....that was great. I was too chicken and lazy to point out the problems with the point mutation discussion. And, probably not as well spoken, either.

So. Biology ? Genomics ? Me: Stanford Genome Center. Biostatistics. HGP (non Ventner part)

(yes, this is the equivilent of the ex forces types comparing time at fort dix....)

:shock: Are you serious? You worked on the human genome project??

I'm just a punk PhD student have a GPCR/signalling background, just starting work on zebrafish neural stem cell stuff at the moment. My mind is just constantly blown by molecular biology. It's like trying to reverse engineer a machine made by someone who was completely, incomprehensibly insane. I have no evidence that God exists but for me I'm not sure it matters because if this is what he made, I don't think I have any way of interpreting what he might want anyway!! :?

 

[kristof65]

TL;DR version: Biology is complicated, traveller GMs have lots and lots of wiggle room for weird looking Vilani

Thanks for confirming what I've been trying say, even though I don't have the scientific clout to back it up.

 

[Infojunky]

If you read all of that and think I'm full of crap,

No way, dude....that was great. I was too chicken and lazy to point out the problems with the point mutation discussion. And, probably not as well spoken, either. [\quote]

I concur, no way I could have write such a well laid out explanation. That and I am a coward. I come at the entire subject from the Evolutionary Anthropology (note I fell in with the the Cladistics heretics, thus a higher than average familiarity with genetic lineages)..

So. Biology ? Genomics ? Me: Stanford Genome Center. Biostatistics. HGP (non Ventner part) [\quote]

Gee, no way to match that with my paltry BS in Geography....

(yes, this is the equivilent of the ex forces types comparing time at fort dix....)

I can do that one.... But not with Fort Dix....... Subic Bay anyone?

 

[aspqrz]

TL;DR version: Biology is complicated, traveller GMs have lots and lots of wiggle room for weird looking Vilani

Thanks for the clear(er) explanation for a historian (soft "science", y'know ... excuse us silly duffers ) ... I don't think we actually disagree, I just didn't entirely grasp your argument ... and I wasn't saying (tho I may not have been as clear as I should have been, either :wink: ) that it was impossible, merely not very likely, that blondes/light skinned people with the same mutation would occur then survive on Vland ... but I had no clear idea of the underlaying mechanism beyond a layman's (historian interested in the history of science and technology, but not a scientist, per se, y'see :shock: ).

However, more clarification ... OK, there is a larger "area" in which mutation that affects hair/skin colour can occur on the genome ... I get that ... but, if it is a larger area, then surely there would be more variations in skin/hair colour than those that exist in actuality and which have come to exist over the last 500,000 years that something like modern humans or reasonably close ancestors have existed.

Basically, apart from Brown and Black and slight variations on them, there's Blonde and, as I understand it, Red, which is a slight variation on Blonde for hair ... or White, for albinism, of course ... and for skin there's "black" and shades, "brown" and shades, "copper/red" and shades and "white" and shades.

In half a million years ... longer, one presumes, if skin colour variations go back to earlier protohumans ... and that's *it*.

If it's such a big area subject to mutation, then why so few in such a long period of time?

I'm guessing its partly because most mutations, even ones that aren't immediately deleterious, or deleterious in that they prevent or reduce the chances of an organism reproducing, often don't have any definite pro-survival traits and/or are recessive and therefore disappear quite easily (and, yes, I know this is not entirely true ... but it was what I was taught in Science in the late 60's, and, unless corrected, I understand its not entirely incorrect either :? ) ... ???

Given that, then it would seem not entirely unlikely to assume, as I did, that it is extremely unlikely that you'll see Vilani blue eyes, blondes etc. Not that Vilani will, necessarily, be otherwise identical to baseline humans ... as I noted, the idea of evolutionary adaptation to different local foods is highly likely for a start.

Since Vland is subject to higher solar output, it would be possible, for example, for some Vilani to have mutated for a functional nictating membrane (there is evidently one mammal that still has one), and this might be as common on pre-spaceflight Vland as blonde hair is on Terra. And, of course, it could be a definte plus for Vilani Scouts or Spacers ...

Phil

 

[aspqrz]

Since Vland is subject to higher solar output, it would be possible, for example, for some Vilani to have mutated for a functional nictating membrane (there is evidently one mammal that still has one)

And, of course, Vulcans have them as well ... and they can cross breed with humans despite having copper based blood 8)

Phil

 

[subunit]

Thanks for the clear(er) explanation for a historian (soft "science", y'know ... excuse us silly duffers ) ... I don't think we actually disagree, I just didn't entirely grasp your argument ... and I wasn't saying (tho I may not have been as clear as I should have been, either :wink: ) that it was impossible, merely not very likely, that blondes/light skinned people with the same mutation would occur then survive on Vland ... but I had no clear idea of the underlaying mechanism beyond a layman's (historian interested in the history of science and technology, but not a scientist, per se, y'see :shock: ).

Yeah, the only thing I disagreed with was the notion of being able to judge the probability of blondes emerging on evolutionary timescales with only our own particular history

However, more clarification ... OK, there is a larger "area" in which mutation that affects hair/skin colour can occur on the genome ... I get that ... but, if it is a larger area, then surely there would be more variations in skin/hair colour than those that exist in actuality and which have come to exist over the last 500,000 years that something like modern humans or reasonably close ancestors have existed.

Basically, apart from Brown and Black and slight variations on them, there's Blonde and, as I understand it, Red, which is a slight variation on Blonde for hair ... or White, for albinism, of course ... and for skin there's "black" and shades, "brown" and shades, "copper/red" and shades and "white" and shades.

In half a million years ... longer, one presumes, if skin colour variations go back to earlier protohumans ... and that's *it*.

If it's such a big area subject to mutation, then why so few in such a long period of time?

I'm guessing its partly because most mutations, even ones that aren't immediately deleterious, or deleterious in that they prevent or reduce the chances of an organism reproducing, often don't have any definite pro-survival traits and/or are recessive and therefore disappear quite easily (and, yes, I know this is not entirely true ... but it was what I was taught in Science in the late 60's, and, unless corrected, I understand its not entirely incorrect either :? ) ... ???

Couple of things going on here, I think, although this question is probably above my paygrade. The production of melanin in primates likely evolved in response to selective pressure from solar UV. Melanin is a relatively simple pigment to make using existing cellular machinery (such as the ancient and venerable tyrosinase, present even in lowly plants) and probably emerged without too much mutational jiggering of the machinery.

If we take the out-of-africa hypothesis to be correct, and evidence suggests that it is, we can see subsequent evolution of lighter skin tones, hair colours, etc- not as a function of increasing diversity, but of the entropy that occurs in a system after you remove selective pressure. Many of the alleles which have been identified as being responsible for lighter skin tones, blonde or red hair, etc, are thought to have emerged in populations migrating into regions where UV exposure was less intense. There was no strong selective pressure against light skin here, and indeed there may have been pressure for it, as I believe you mentioned earlier with the vitamin D story. Additionally, not many of the new colours being generated had much active selection pressure against them (brown hair or blue eyes doesn't make you much more susceptible to predation, etc).

Since melanin is the pigment we're set up to make, you have to accept certain constraints. You only have two pigment colours to work with (the two melanin subtypes). All possible colours are defined by the relative mixture of the light absorption spectra of those two pigments!!

So I guess if your question is "why don't we produce crazily coloured pigments like birds or glow-in-the-dark proteins like jellyfish or coral", answering that is DEFINITELY above my paygrade. We might start by asking how Mandrills produce the bright red and blue pigments in their faces, I suppose!

 

[aspqrz]

So I guess if your question is "why don't we produce crazily coloured pigments like birds or glow-in-the-dark proteins like jellyfish or coral", answering that is DEFINITELY above my paygrade. We might start by asking how Mandrills produce the bright red and blue pigments in their faces, I suppose!

Actually, that was, more or less, my question ... why not the bright red and blue? They're sorta distant relatives after all :?

I get it that its not your area of expertise, though, so don't sweat it ... but, does anyone know ... or have any (even vague) idea?

If I understand what you said, you're saying that the choices melanin give us are likely (well, more likely ... perhaps even overwhelmingly so), on Vland, only to end up producing darker skin and hair colouration ... unless, by extension of your other comments (and some of mine, which I am assuming are right), the developments are somehow tied with something else that might make them more pro-survival than the trend towards darker skin/hair/eye colour would normally be.

Phil

 

[aspqrz]

So I guess if your question is "why don't we produce crazily coloured pigments like birds or glow-in-the-dark proteins like jellyfish or coral", answering that is DEFINITELY above my paygrade. We might start by asking how Mandrills produce the bright red and blue pigments in their faces, I suppose!

Actually, that was, more or less, my question ... why not the bright red and blue? They're sorta distant relatives after all :?

A quick search and I found this ...

http://research.yale.edu/ysm/article.jsp?articleID=290

... which, even though a popularisation, is mostly double dutch to me ...

I think they're saying that the blue is not caused by melanin, but beyond that, blowed if I understand it ... :? :? :?

Anyone?

And then there's Cecil's take from Straight Dope (which I always find interesting) ...

http://www.straightdope.com/columns/read/2376/why-arent-green-or-blue-naturally-occurring-human-hair-colors

... which explains, perhaps, why we don't have blue hair ... but not why mandrills have blue skin ...

Phil

 

[captainjack23]

If you read all of that and think I'm full of crap,

No way, dude....that was great. I was too chicken and lazy to point out the problems with the point mutation discussion. And, probably not as well spoken, either.

So. Biology ? Genomics ? Me: Stanford Genome Center. Biostatistics. HGP (non Ventner part)

(yes, this is the equivilent of the ex forces types comparing time at fort dix....)

:shock: Are you serious? You worked on the human genome project??

Yeah.....with Ron Davis, FWIW....I was one of many informaticians and Biostatisticians who made the data flow.....not a real geneticist at all -but one has to pick it up.

Actually got included in the final publication in Nature -(NOT the one on the cover....the extended credits with 200+ people, I hasten to add)

I'm just a punk PhD student have a GPCR/signalling background, just starting work on zebrafish neural stem cell stuff at the moment. My mind is just constantly blown by molecular biology. It's like trying to reverse engineer a machine made by someone who was completely, incomprehensibly insane. I have no evidence that God exists but for me I'm not sure it matters because if this is what he made, I don't think I have any way of interpreting what he might want anyway!! :?

Neuroscience ? Cool. My first love. Yeah, if someone asks me if I believe in God, I paraphrase Calvin and Hobbes: "Well, someone is trying to screw up my research..."