h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

From google:
Methionine, cysteine, homocysteine, and taurine are the 4 common sulfur-containing amino acids, but only the first 2 are incorporated into proteins.

I seem to remember that it's cystein bonds that make the curls. And that's why permanent wave procedures are so smelly - breaking and reforming those sulphur bonds.

My own hair has turned curlier over the last ten years - at least when wet. When it's dried and brushed, it's merely wavy. But before brushing? Almost corkscrews!

Regarding balding animals:

Actually, they do—I’ve seen hair or fur loss in several animals, including coatis, Andean bears and cats of various species. In most cases, the animal was well past the average life expectancy of its species, so my guess is that animals in the wild tend not to live long enough to suffer this effect of aging, unless they have a disease that causes their hair or fur to fall out.
Craig Saffoe, Curator of Great Cats
National Zoo


Read more: http://www.smithsonianmag.com/arts-culture/why-dont-animals-go-bald-like-humans-and-other-questions-from-our-readers-90672666/

makes sense... as humans aas a species are living well beyond their origional average expected life span due to nutrition and lack of predation plus medacin I guess thesedays

It could be that humans go bald as a sign of status, just as the gorilla develops a silver back.

My Father has gone bald, and has a silver back. its quite disturbing in the summer, when he's working outside, without a top on, chainsawing wood...

... with his teeth

sadly... not far form the truth I think he's only kept alive thesedays by the vodka... and chain-smoking

On full frontal pattern baldness, its caused by a sub-dominant* gene on the X chromosome which can be masked by a gene on a matching X chromosome which doesn't carry the full frontal baldness gene, which is why women have the condition less frequently than males; the genevhas to be present on both their X chomosomes to manifest, men have only one X chromosome.

Men always inherit the trait from their mother.

Women can pick up a copy of the gene from either parent, but will have active pattern baldness only if both their parents have the trait, or both father and maternal grand-father do.

I've known two women who've got the condition, one in her early middle years, the other in her late senior years.

The medieval Japanese considered the trait so manly that they deliberately shaved the fronts of their heads to simulate the condition.




On hair curling treatments, on of the simplest natural means is with alternating beer and egg treatments.

The beer breaks the sulfur links, more is supplied by the egg yolk.




Highlights in hair color, for example purplish or bluish iridescence with a brunette, is a diffraction effect depending on the size the scales on one's hair.




*Genetic dominance depends on the number of iterations of a given gene.

If there's only one iteration on a given haploid set of chromosomes its always a recessive, manifesting only if there's a matching gene on the complementary haploid set of chromosomes.

Relative dominance arises when there are two or more copies of the relevant gene.

If, for example, there's a doubled set of genes on X-chromosome, it always manifests as a dominant with a male, but can be over-ridden by a quaduple set of genes coding for non-pattern baldness on the matching X-chromosome with a female.

"It could be that humans go bald as a sign of status" [Quotes]

I don't want to sacrifice my hair just to raise my status.