[Vicki]

>Vicki,
>
>Melanin is produced by melanocyte -
>melanin producing cells in the skin.
>This mecahnism is triggered by a hormone
>- called melatonin, secreted by by the
>pineal gland. This a physiological
>process, not genetical.

Thank you. Is it genetic if we go down to the basic unit of the cell?

[MsJackson]

CountryBoy!
Did you mind asking the white chic why they also come in different shades!!!? :D :D :D!
You know too well, white pple don' have the same skin tone, there those that have a darker tint in them and others who are.......can I say pink?

[Points]

The answer to this question is one: genes.
Besides environment and other factors skin colour determination by genes is the only persistent factor. This means that although you may become darker skinned by living in hotter areas or if you are white you tan, this doesn't mean your children will be tanned, because this is an accuired trait and accuired traits are not inherited.
Amount of melanin pigment is you actual colour determinant with darker people having more than lighter ones.
Although hormones as someone said signal for melanin production, genes dictate that this should happen.
Lastly, to answer your question completely, skin colour is not an extreme trait such that you are either black or white and that is why we may all have those different hundred tones.

[lale]

>.......In the winter I am real light
>skinned and in the summer I tend to
>become darker!

THATS WITH ME TOO!...AMA AJE VICKI!!?..;-)

[Vicki]

Lale, You mother is Italian. What do you expect???????????????????

[lale]

>Lale, You mother is Italian. What do you
>expect???????????????????

YEH BANA...TRUE DAT FO SHO..LOL! :7

[countryBoy]

thanks all of u for ur contributions but i geuss i am still not satisfied by the many answers... a a few questions still linger in my mind.

1. sadik u said white folks have less melanin cos of the cold weather...but if a blk person is born there how come then the melanin is still being produced? i geuss thats where the phenotypes come in place

2. MsJackson white folk surely dont come in same shade but they are much more similar than we are ( they are good imitations of each other)....i geuss their difference comes in their hair where they have redheads, blondes, brown hair, ama thats where their melanin goes to?

[Sadik]

cb

Once again my answer is KCSE Biolgy level.

Black people are not indigenous of these temperate countries. Remember for genetical trait to develop it needs long time to evolve. Human life span is around 100 yrs. For evolution to take place you needs thousands of yrs.

[mkamba]

These are some of the things that God did not want man to know.... as soon as i see him countryBoy i will try and make sure thats the first question i ask him and let u know.

[shidanyingi]

And I will add.....

Melanine is contained inside melanosomes bladder. A darker skin has more numerous melanosomes. The melanization process is regulated by attractine protein, which is built from the amino acid tyrosine.

Why there is too much of these melanine in tropical areas, eg African descent?

This is a tough question but the answer seems to be leaning towards the theory developed by a UK biologist, Dr James Mackintosh, which I will paraphrase here.

“He believes that long time ago, tyrosine was most likely conserved to make essential proteins when food was scarce in cold, dry areas. This was then converted into extra melanine in the warm, damp tropics where food was abundant and diseases rampant”. Africa?, hmmmmm........most possible candidate.....

After that genetics took over.