O/T Black Parents - White Baby

rjsterry

Well, why didn't you say so in the first place instead of letting us partially-informed types blather on?

Next, I'll be saying that atoms are little groups of 'balls' with other 'balls' whizzing round them. :roll:

I'd imagine there's a fair amount of unintended consequences with genetic mutation (not that there is such a thing as an intended consequence with a random mutation, but you know what I mean). For example, I believe the mutation that causes sickle-cell aneamia is also the mutation that provides some protection against malaria.

sarajoy

Wow.

Impressive!

Always assumed skin colour and race-specific features would blend together rather than be an on/off phenomenon like red hair can be - so very strange! Be interesting to find out how this baby looks as she grows up...

notsoblue

rjsterry wrote:

For example, I believe the mutation that causes sickle-cell aneamia is also the mutation that provides some protection against malaria.

Yep, sickle-red blood cells malform when they're infected with the malaria parasite, and get taken out by phagocytes. Fascinating stuff.

I wonder if the baby's appearance is due to a mutation affecting melanin production, or wether its a racial trait thing. i.e. Will the baby have afro features but light skin and blonde hair. Its a shame the article doesn't actually go into any of this, but then it is The Sun....

rjsterry

For all those interested in such stuff, I can recommend ""Mutants: On the Form, Varieties and Errors of the Human Body" by Armand Marie Leroi.

cee

rjsterry wrote:

Well, why didn't you say so in the first place instead of letting us partially-informed types blather on?

well with statements such as...particular hair structure is because it keeps you warmer/cooler....etc..............

just ends up in yesitdoes noitdoesnt type thing...

the actual source of the genetic material is however quite interesting...

far less likely to be a mutation than just having some of that genetic material somewhere in the ancestry!

rjsterry

lost_in_thought wrote:

MonkeyMonster wrote:

Exactly RJS - its called "fitness" in biological parlance. If its beneficial then natural selection will assist in it propagating through the rest of the species.

Have to say though DDD - not sure I've ever heard that "black" hair ie oval cross sectioned hair (which is why it curls) was due to a temperature benefit. I suspect that hair types and the locales that you know find them in were more to do with social expectations/desires. That nordic people have straight flaxen hair I suspect is not to do with it being easier to tidy up under their norse helmet before they go raiding We should ask LiT - she has nordic hair

Flaxen it may be, straight it sure ain't.

EDIT: See? (8-year-old photo)

Straighteners, innit MM.

MonkeyMonster

notsoblue wrote:

rjsterry wrote:

For example, I believe the mutation that causes sickle-cell aneamia is also the mutation that provides some protection against malaria.

Yep, sickle-red blood cells malform when they're infected with the malaria parasite, and get taken out by phagocytes. Fascinating stuff.

Close. If memory serves the benefit comes from when a malarial infected blood cell bursts to release more of the evil buggers - the sickle cell affected blood cells nearby are affected by said burst cells contents (higher concentration of H+ ions, ie acidic) and then fold into the sickle shape characteristic of the affliction - thereby being unable to be infected my the malaria parasite [the cell membrane is bolloxed] - phagocytes (immune system) then come and mop up the entire area meaning that infected blood cell can't infect any others and all the parasites are mopped up too.
The problem being if sufferers do exercise - the lactic acid has the same affect but can affect larger volumes of red blood cells and the person suffers from anoxia. Homozygous sickle cell sufferers are buggered basically - can't do anything more than sitting about without causing that affect.

and there ends the biology lesson...
Feel free to poke holes

edit: Oh, straightners hell yeah and DDD I was talkin about head hair, not all over body hair - what is the evolutionary benefit of black style hair?

cee

means you can have wicked hair styles like a big 'fro...which the ladies love...so it helps procreation.....

ok this isn't always true

white boys can't get away with a 'fro

this IS always true

at this point...i'd settle for a full covering.

yip..also true

DonDaddyD

MonkeyMonster wrote:

edit: Oh, straightners hell yeah and DDD I was talkin about head hair, not all over body hair - what is the evolutionary benefit of black style hair?

My head hair is nearly exactly the same texture and curlyness as the rest of the hair on my body. You could run a afro comb through my pu....

It could be argued, I suppose, as a mostly redundant feature what with cyclist caps and helmets etc. But its design is rooted in the help keep warm, keep moisture in, reflect heat needs of our ancestors. 'Black style hair' I was told was designed to retain moisture while its darkness did something to reflect heat (I'm not sure why). While long straight hair came about from the need to keep warm.

I can't accept that evolution determined my physical feature to better handle hotter climates and yet somehow didn't know what to do with my head hair.

Agent57

DonDaddyD wrote:

'Black style hair' I was told was designed to retain moisture while its darkness did something to reflect heat (I'm not sure why). While long straight hair came about from the need to keep warm.

This strikes me as being back to front, but I suppose it fits with polar bears. Can someone explain how black hair would help someone stay cool? I thought darker objects absorbed more heat, while white things reflected it.

notsoblue

MonkeyMonster wrote:

edit: Oh, straightners hell yeah and DDD I was talkin about head hair, not all over body hair - what is the evolutionary benefit of black style hair?

At a guess I'd say that curly dark hair is a better barrier from the sun because a) darker materials absorb radiation better than lighter and b) curly hair is more dense and a better insulator.

Point a also applies to skincolour I believe. Darker pigmentation at the very surface of the skin protects more vulnerable deeper layers of tissue from solar radiation. Useful around the equator, but I suppose the downside to this in less sunny climes is that people with darker skin produce less Vitamin D with the sunlight available than those with lighter skin. Hence it being beneficial for those in the far north to be more fair skinned.

All guesses of course. Please pick holes!

lost_in_thought

notsoblue wrote:

MonkeyMonster wrote:

edit: Oh, straightners hell yeah and DDD I was talkin about head hair, not all over body hair - what is the evolutionary benefit of black style hair?

At a guess I'd say that curly dark hair is a better barrier from the sun because a) darker materials absorb radiation better than lighter and b) curly hair is more dense and a better insulator.

Point a also applies to skincolour I believe. Darker pigmentation at the very surface of the skin protects more vulnerable deeper layers of tissue from solar radiation. Useful around the equator, but I suppose the downside to this in less sunny climes is that people with darker skin produce less Vitamin D with the sunlight available than those with lighter skin. Hence it being beneficial for those in the far north to be more fair skinned.

All guesses of course. Please pick holes!

Agreed re the skin colour, just put jonginge or brun in the sun for a while to understand the benefits of darker skin!

On the hair, though, I'd say curly hair = better insulator +darker = absorbs heat, but teh combination is therefore likely to make you hotter as it traps more air. You don't see puffa jackets being used a lot in the heat! I was of the understanding that paler colours reflect heat whereas darker colours absorb it... so surely very dense straight white hair that sits close to the head is better for dealing with heat?

We need a scientist who understands these things. A Trichologist, maybe. If such a thing exists.

DonDaddyD

Agent57 wrote:

DonDaddyD wrote:

'Black style hair' I was told was designed to retain moisture while its darkness did something to reflect heat (I'm not sure why). While long straight hair came about from the need to keep warm.

This strikes me as being back to front, but I suppose it fits with polar bears. Can someone explain how black hair would help someone stay cool? I thought darker objects absorbed more heat, while white things reflected it.

Long straight hair is so because it keeps you warm. That's why most animals from colder climates have long straight hair.

Short curly hair, holds moisture in better, does nothing to keep my ears warm, or my face - this is due to its length.

tailwindhome

Will evolution lead to an all black or an all white Zebra?

And will they live side by side?

On my piano keyboard

Why can't we?

Jay dubbleU

cee wrote:

DonDaddyD wrote:

Splottboy wrote:

BRITISH = Anglo "Saxon", German.
Jutes, German/Denmark.
Vikings, Scandinavian/French.
Normans, as above,
Celts, Austria.

You forgot Romans. I like the Romans.

what about the greeks? they had awesome gods and monsters....

So did the Vikings! 8)

LiT is probably part Valkyrie

DonDaddyD

TailWindHome wrote:

Will evolution lead to an all black or an all white Zebra?

And will they live side by side?

On my piano keyboard

Why can't we?

The Conservatives won't let us

They fear what they don't understand

They also need to feel better than someone else

There, I've said it.

rjsterry

DonDaddyD wrote:

MonkeyMonster wrote:

edit: Oh, straightners hell yeah and DDD I was talkin about head hair, not all over body hair - what is the evolutionary benefit of black style hair?

My head hair is nearly exactly the same texture and curlyness as the rest of the hair on my body. You could run a afro comb through my pu....

It could be argued, I suppose, as a mostly redundant feature what with cyclist caps and helmets etc. But its design is rooted in the help keep warm, keep moisture in, reflect heat needs of our ancestors. 'Black style hair' I was told was designed to retain moisture while its darkness did something to reflect heat (I'm not sure why). While long straight hair came about from the need to keep warm.

I can't accept that evolution determined my physical feature to better handle hotter climates and yet somehow didn't know what to do with my head hair.

Designed? Evolved surely; never had you down as a creationist/ID-type

I'm no palaeontologist or palaeo-anthropologist, but I believe most of the early hominids evolved in what is now Africa, as did Homo sapiens, so we probably all started off black, and then 'faded' as we moved north. I'm not sure the colour of hair or skin is related to keeping warm or cool as we have other ways of dealing with heat: sweating. The greater protection from UV that dark skin/hair affords is a better explanation. Can't think of a good reason for the curliness other than the moisture retention already mentioned.

Jay dubbleU

The zebra will probably stay as it is unless there is a dramatic change to its environment - black and white stripes make it harder to spot individuals in a herd than completely either black or white

DonDaddyD

rjsterry wrote:

Designed? Evolved surely; never had you down as a creationist/ID-type

Nah, just bad english... If I was designed, I'd take me back sue the twunt and demand a new body in the mold of Eddy Merckx....

The greater protection from UV that dark skin/hair affords is a better explanation.

Yeah I can accept that because I understand it.

Can't think of a good reason for the curliness other than the moisture retention already mentioned.

Thank you. Finally. I thought I was going to have to measure the time it takes my hair to dry compared to Mrs DDD.

On sweating, is that why we see naturally maller dogs in hotter countries?

snailracer

Google "leucism" - white skin/fur, normal coloured eyes.

MonkeyMonster

DonDaddyD wrote:

That's why most animals from colder climates have long straight hair.

Just to single you out because its more fun - but most animals have fur - not hair... and yes there is a difference. Polar bears fur fibres are actually transparent not white.

Some serious bogus "science" being banded about here

As for why body hair "could" have evolved differently to head hear is because of cloth/coverings. If an afro is so good at keeping in moisture etc - why on almost all programs about africa do they have/keep their hair short?

Black objects absorb heat better than whiter objects - melanin protects against uv radiation damage. We likely bred it out as we went further from the equator because we no longer needed it plus social forces wanted paler skin so forced it out that way in conjunction...

Runoutofgears

And the drains, sanitation, that's what they gave us.

rjsterry

DonDaddyD wrote:

On sweating, is that why we see naturally maller dogs in hotter countries?

Could be, but dogs are kind of a special case as AFAIK virtually all the breeds are man-made, rather than naturally occurring. They are also unusual in that you can get such a huge variation within a single species. Apparently, if you tried to breed a whole load of different cats or sheep or pretty much anything else with the same degree of variation it just wouldn't work. They'd all still look pretty much like cats or sheep or whatever.

notsoblue

lost_in_thought wrote:

notsoblue wrote:

MonkeyMonster wrote:

edit: Oh, straightners hell yeah and DDD I was talkin about head hair, not all over body hair - what is the evolutionary benefit of black style hair?

At a guess I'd say that curly dark hair is a better barrier from the sun because a) darker materials absorb radiation better than lighter and b) curly hair is more dense and a better insulator.

Point a also applies to skincolour I believe. Darker pigmentation at the very surface of the skin protects more vulnerable deeper layers of tissue from solar radiation. Useful around the equator, but I suppose the downside to this in less sunny climes is that people with darker skin produce less Vitamin D with the sunlight available than those with lighter skin. Hence it being beneficial for those in the far north to be more fair skinned.

All guesses of course. Please pick holes!

Agreed re the skin colour, just put jonginge or brun in the sun for a while to understand the benefits of darker skin!

On the hair, though, I'd say curly hair = better insulator +darker = absorbs heat, but teh combination is therefore likely to make you hotter as it traps more air. You don't see puffa jackets being used a lot in the heat! I was of the understanding that paler colours reflect heat whereas darker colours absorb it... so surely very dense straight white hair that sits close to the head is better for dealing with heat?

We need a scientist who understands these things. A Trichologist, maybe. If such a thing exists.

My thinking was that it wasn't so much the heat that applied evolutionary pressure, but the UV radiation. So dense dark curly hair is the best way to protect from the sun. There are other ways to cool down, and besides, the thermal insulating properties of curly hair goes both ways. I had quite a fro going until I got it cut this afternoon, doesn't get too hot in the sun On the other hand I have white, straight haired friends who get sunburnt scalps if they're not careful :P

snailracer

Natural selection is sometimes driven by sexual selection, rather than adaptation to the environment. Consider the peacock's tail, which is a hindrance to flight. Consider large breasts on women (relative to other primates), a hindrance to breastfeeding.

Splottboy

Reg: "But where's the foetus going to getstate? In a BOX!"

Mary "No, he doesn't want a baby, he wants the "RIGHT" to have a baby!"

notsoblue

snailracer wrote:

Natural selection is sometimes driven by sexual selection, rather than adaptation to the environment. Consider the peacock's tail, which is a hindrance to flight. Consider large breasts on women (relative to other primates), a hindrance to breastfeeding.

Some heavy climatic correlation here though:

The Rookie

curly hair is useful I would say to insulate the skin of the head from the heat of the sun being absorbed on the top surface, you can't stop the top layer of hair getting hot so need to insulate that from the scalp! Same reason Arabs wear thick woolens, to insulate the body from the suns heat absorbed by the surface of the material.

Simon

snailracer

notsoblue wrote:

snailracer wrote:

Natural selection is sometimes driven by sexual selection, rather than adaptation to the environment. Consider the peacock's tail, which is a hindrance to flight. Consider large breasts on women (relative to other primates), a hindrance to breastfeeding.

Some heavy climatic correlation here though:

Skin colour, I'd certainly agree. Afro hair, not so much.

lost_in_thought

That's a really interesting pictoral thingy. Funny how there are dark bits in India too, and those other two countries (malaysia and indonesia? I'm ashamed of my geographic knowledge right now) yet nothing in south america.