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Sunday, June 10, 2018

Our white skin

We "whites" seem inordinately proud of our white skins.  We have always considered it to be a sign that we are superior to the darker variety of homo sapian.  So I thought it would be fun to consider where our white skin came from.

We all know that people living in sunny climates which includes much of Africa, where we originated, have dark skins.  Undoubtedly, this included all the species of the genus Homo that preceded us.  Look at our nearest relatives, the Chimpanzies and great apes.  All with black skins despite the fact that they live, for the most part, in jungles.  Early hominids must have spent many hours in the sun and often, due to warm temperatures,  went with limited body covering.  They had to spend considerable time in the open finding their daily crust of bread and they developed dark skins to protect their skin from too much sunshine.
 Image result for image chimpanzees

Note that the babies have white faces while the adult is black.  Why do you think this might be.

Sunshine of course, provides us with vitamin D which is essential for the calcification of strong bones.  A hominid with weak fragile bones hasn't got much of a show in an environment in which his speed agility and strength will often make the difference between eating or being eaten.


But, vitamin D is important for so much more and we keep finding additional functions  of this important vitamin.  Some functions which have so far being discovered include:

*Strengthened immune system
*Enhanced muscle function.
*Improved lung health
*Anti-inflamatory properties
*Reduced blood pressure
*Reduced hardening of the arteries
*Protection from kidney disease
*Suppression of a pathogenic appetite
*Protection agianst Alzheimer

So there is a strong selective pressure for anything that ensures you obtain enough vitamin D

Sunshine is not the only source of vitamin D either.  Other sources include:
*Fresh fatty fish
*Oysters and some other 'shell fish'
*Some livers
*Cheese
*Egg yokes
*Raw milk
*Some mushrooms
*Some fish eggs.

Think of the dilemma of the first hominids that left sunny Africa.  Those that migrated along the coast toward India had little selective pressure to evolve a light colored skin.  Not only did they migrate through sunny climates but if they were able to fish, they would have got their vitamin D that way.

However for those that left the beach and migrated northward it was a different story.  There was a double whammy against them.  First, if they migrated into northern climates, it was more cloudy giving them less exposure to sun.  In addition in these colder climates, they would have had to dress in skins or clothes made of wool which was shed annually by various woolly animals.  They probably had only their face and hands exposed to the sun so there was a strong selective pressure to loose their protective melanin so that they could obtain their vitamin D.

For the males, there was another factor.  We had beards, possibly for the same reason that a male peacock has beautiful feathers so even less of our skin was exposed to the sun.

The interior of continents are very warm in the summer so they probably also evolved the ability to sun tan, if they didn't have this already.

According  to our present archaeological knowledge, Homo erectus  arrived in Eurasia at least 1.6million years ago.  For those that challenged the northern interior of the continent, there would have been a strong selective pressure for the evolution of a white skin.  Erectus sites from 1.6m years ago contain  flint tools including  retouched flakes so he was no dummy and it is not unreasonable to assume he fashioned some sort of covering.

Homo erectus likely evolved into  Homo heidelbergensis and then into
Homo neanderthalensis.  It is unlikely that this was a new migration from Africa since neanderthal genes are found in European people of today but not in modern Africans.  Incidentally another species which may have developed from Homo erectus is Homo sapiens denisova  further East in Asia.  Presumably, Denisovians who lived in northern climates characterized by cold cloudy conditions, they also had pale skins.

But there is something curious.  Bones of Homo sapien have been found in Africa from 315,000 years ago but only appeared in the fossil record in Europe 45,000 years ago.  How come.  Of the various theories presented, my favorite is armament.  It is likely that Neanderthals and our species came into contact much earlier than 45,000 years ago in the bridge from Africa to Europe, namely in the middle East. Think what a conflict that would have been.  The gracile Homo sapien comes up against the powerful, robust Homo neanderthalensis who makes his living stabbing large and small animals at close quarters with his spear.  No prizes for working out who would win that contra-ton.

I suspect the critial development which allowed our species to make inroads into Eurasia was the development of throwing weapons.  This could have included the lance, atyl atyl*, sling and even the bow and arrow

*Trowing stick which allowed a spear of a size between a lance and an arrow to be thrown with much more force that with the hand alone.

Our whole history is one of killing at greater and greater distances*.  It has culminated now with cowardly soldiers sitting safely in America, killing people with gattling guns and hell fire missils from their drones in other peoples countries as if they were in some sort of video game.

*In more modern times, the Battle of Agincourt

Neanderthals were at two disadvantages.  Their culture was one of killing prey close up and with humans the way we are, there was probably a strong sexual selection for the man that did this most effectively.  You bring home the bacon and the girls want you for their mate. So their whole culture favored the man who was a real man and could kill a deer at close quarters. But they had a second disadvantage.

You would think that they would rapidly adapt throwing weapons once they saw how effective they were.  Unfortunately, through evolution, they had evolved a shoulder joint that while it was very powerful, it was not adapted for throwing.  Even if they wanted to adopt the new weapons, they would have been very clumsy at it. Neanderthals lacked a throwing arm.

An effective throwing weapon would have completely changed the balance of power. And again, the way we are, when a tribe of Sapiens defeated a tribe of Neanderthals, they probably killed all the males and took the females for themselves.  Here a little diversion into genetics.


With the difficulty of travel when all you could call upon were your legs, and considering how territorial humans are, the two tribes were what we might consider pure breeds.  In other words, they would have had a high degree of homozygosity* at many more sites on their chromosomes than modern humans who breed with other humans who are distant both in geographical terms and in their genetics.

*Each cell of our bodies has two copies of each chromosome.  The genes on each chromosome at the same locus can be the same (homozygose) or different (hetrozygose).  When closer related individuals mate, this increases homozygosity and of course when a recessive lethal gene or even a disadvantagous gene comes together in an individual, he is either dead or disabled.  Inbreeding over time, to some extent, weeds out deleterious recessive genes from the population.  When two inbred individuals from different genetic lines breed, their offspring are likely to be particularly robust

 We keep chickens for the production of eggs.  We start with a variety called brown shafers who are great layers.  They are a hybrid of at least 4 so called pure breed varieties and express hybrid vigor. However we allow them to breed freely and you should see the varieties of chickens produced.  They not only revert to the original varieties but produce all sorts of assorted mixes.

Imagine the offspring of this first mating of male Sapien with female Neanderthals.  The two populations had been isolated and inbreeding for thousands of years.  The result would have been the equivalent of our Brown Shafers.  They would have all looked very similar and likely would have been very strong with a somewhat better throwing arm than Neanderthals but not a good as Sapien and with an intermediate skin colour.

In order not to make the whole story too complicated, I will assume that a throwing shoulder is determined by one gene and likewise skin color.  Any genetisist will tell you that many genes are involved in the determination of these characteristics and most others.  Mendel lucked on to some characteristics of peas that indeed were determined by one gene and so laid the basis of genetics.  I will also assume that both genes have equal influence.  That is neither is dominant over the other.  We will use W for a white skin and w for a dark skin.  Also T for a throwing shoulder and t for a non throwing shoulder.  This is a huge simplification but will make the situation easier to understand.

In what the genetisists call the F1 generation we have a cross between two quite homozygous populations (pure bred) The offspring will have half their genes from the mom  and half from the dad and those from all the dads will be quite similar to each other and likewise all those from the moms, similar to other moms.  Then the fun starts.

When the children start to reproduce, their offspring will have all sorts of mixes of these genes.  We will have:
WWTT - a white skin and a throwing shoulder
WwTT - a dusky skin and a throwing shoulder
wwTT - a dark skin and a throwing shoulder
and so forth.  Use a Mendelian square to work out all the variations.  On one axis you put WT, Wt, wT and wt and the same on the other axis.  These are the genes in the gametes (eggs and sperm).  Now selection begins.  Since humans are nasty and of great danger to each other, a throwing shoulder will be selected for as will a lighter skin, especially as these hybrid humans move away from the coast into more northern areas.

We have all heard by now that we have a small percent of Neanderthal genes.  This begs the question of what is a species.  The old definition was that two individuals are of the same species if they can produce a viable offspring that itself can breed and produce viable offspring.  Of course the situation on the ground is more complicated than this.  Apparently the various species of hominin in Africa bred back and forth in all sorts of combinations and clearly we bred with Neanderthals.  Otherwise we wouldn't have their genes.  Over the thousands of years since we started to breed with Neanderthals, individuals would be selected with characteristics from both strains of human that had the best survival.  Here we have only considered two.

I suppose we we were lucky to breed with a species that had already adapted to northern climates.  It would have speeded up considerably our rate of adaptation as we kept those characteristics that benefited us rather than having to start with favorable mutations - a much slower process.

We can thank the Neanderthals for our white skin.

Post scriptum
Facts are such a bitch when it comes to a great theory.  It was great fun poking fun at the white supremicists but it turns out that it probably is not true.  Have a look at the youtube videos from this chap.   Apparently it is true that at least some neanderthals were white and interestingly they had red hair.  The whatsit in the woodpile is that the genes that make present day whites, white are different from the ones that made Neanderthals white.  We seem to have evolved out own genes to turn our skin white and hence give us our daily dose of Vitamin D.

Now, of course, this doesn't mean necessarily that all Neanderthals were white.  If there was a population that lived in sunny parts of the world or on the sea shore where they got enough vitamin D from the sea, they could well have been black or brown, just as present populations of humans display all color variations.  Anyway, so much for a fun theory.




Monday, April 23, 2018

Brown flour

Brown flour just ain't what is is cracked up to be.  Let me quote a paragraph or two from The Third Plate by Dan Barber (incidentally, highly recommended)

"The roller mill appeared in the late 1800's just in time to expand the divide between the wheat field and the table.  It was a technological breakthrough that revolutionized the wheat industry just as the cotton gin had done for the cotton industry a century earlier.  Until its widespread use, people used stone mills.  Stone mills like the one we use at Blue Hill work like molars, crushing the kernels between two large stones.  They are effective, but slow and tedious, and they do little to separate the kernel into its component parts, a key development in the drive to industrialize flour.
 Image result for image a water powered flour mill


A few years ago, Klaas's wife, Mary-Howell showed me a picture of a wheat kernel in cross section.  It looked like an ultrasound image of a six-or seven week old human gestational sac, which isnt a bad comparison; a wheat kernel is a seed, after all.  The grain's embryo or 'germ' is surrounded by the starchy endosperm, - the stuff of refined white flour - which stores food for the germ.  Surrounding the endosperm is the seed coat or bran, which protects the germ until moisture and heat levels indicate it's time to germinate. 
 Image result for image wheat kernel

Whereas stone mills had crushed the tiny germ, releasing oils that would turn the flour rancid within days, roller mills separated the germ and the bran from the endosperm.  This new ability to isolate the endosperm allowed for the production of self-stable white flour, able to be stored and transported long distances.  Overnight, flour became a commodity. 
 Related image


It's hard to fathom that merely removing a temperamental little germ could revolutionize a staple grain, but that's just what happened.  The settling of the Great Plains and the advent of roller-mill technology meant that white flour was suddenly cheaper and more readily available.  Small wheat farms, including those in the former grain belt of New York, couldn't compete. Gristmills dotting the landscape became the stuff of folklore.  The homogenization of the US wheat industry had begun

The whiter flour became, the greater the demand.  To be fair, that's been the history of wheat for thousands of years.  But for all its efficiency, steel couldn't match the old-school grindstone in two key respects.  In fully removing the germ - that vital, living element of wheat - and the bran, the roller mill not only killed wheat but also sacrificed nearly all of its nutrition.  While the bran and the germ represent less than 20% of a wheat kernel's total weight, together they comprise 80% of it's fiber and other nutrients.  And studies show that the nutritional benefits of whole grains can be gained only when all the edible parts of the grain - bran, germ and endosperm - are consumed together*.  But that's exactly what was lost in the new milling process.

*this probably relates to the fact that you need to consume all the amino acids in protein at the same time.  The digestive system takes up amino acids as balanced proteins.  If there is an excess of one amino acid, the excess is rejected. Presumably there are different amino acids in the various components of the wheat seed and only by consuming the whole seed do you get the full nutrition.

There was another cost as well, just as devastating. Stone-milled flour retained a golden hue from the crushed germ's oil and was fragrant with bits of nutty bran.  The roller mills might have finally achieved a truly white flour, but the dead chalky powder no longer tasted of wheat - or really of anything at all.  We didn't just kill wheat,  We killed the flavor.


The Chinese Dilema

You may have wondered why there are so many Chinese in the world today.  The answer is surprisingly simple.  Many many years ago some Chinese genius worked out that in order to have sustainable soils, you have to return every bit of organic material you can to the soil.  This includes animal waste, human waste and all the inedible parts of your crops.  You can also supplement this with material from the sea since you are sending huge amounts of nutrients down your rivers from the land.  It has worked a treat and despite  mongol hoards, palace revolutions and wars, the Chinese have grown and prospered.'

It helped that they had rich deep loes soils gratis of the continental glaciers that ground rock into fine powder to be carried and deposited by the wind but so did America and they have gone through meters of this 'god given' bounty in a few centuries.

In the mean time other empires have prospered and declined as they mined their soils and the area they occupied had to wait for the slow process of building new soils from the bottom up before significant numbers of people could once more occupy the areas where empires once existed.

Back to the Chinese, they are now coming into the 'modern world' and it doesn't auger well for them.  On the nutrient front, they now have flush toilets and will be sending massive amounts of nutrients to sewage plants to be detoxified, denitrified and what is left, sent down to the sea.

It doesn't have to be this way.  For instance, in Seattle, they now have a sewage plant that is turning their 'feed stock' into valuable fertilizer, the sale of which covers half their running costs.  If this becomes the norm instead of the exception, perhaps us westerners can also have a sustainable future.

The Chinese are sinning against sustainability in another way now.  In their rush to industrialize. they are polluting their air to an extreme extent. It is so bad that they are negatively affecting their agriculture.  Never mind. there is light on the horizon.  At the same time they are working as hard as they can to replace coal energy with wind and solar energy and petrol vehicles with electrics.  With their command economy, they will most likely succeed and rather rapidly at that.

In the mean time the Chinese are buying up land all over the world to be able to feed their people.  If they adopt the western model of flushing nutrients down to the sea, they will have to buy up a lot more.

Monday, April 2, 2018

historical sea level




https://upload.wikimedia.org/wikipedia/commons/1/1d/Post-Glacial_Sea_Level.png

Time                         Level
 22000 years ago      Minus 120m
 15,000                                 -107
 10,000                                 -40
   9,000                                 -25
   8,000                                 -15
   7,000                                 -30cm

 

Sunday, April 1, 2018

Electrical demand balancing

Electricity generating companies are facing a couple of problems which can be solved by demand balancing but first, what is demand balancing.

At present, most generating companies monitor the use of electricity and as demand goes up, bring on more generators and as demand goes down, reduce the power output of generators and even shed them.  All generators have a certain range of output so as power demand increases, smaller variations in demand can be met by increasing the amount of power produced by a given generator but beyond a certain level, more generators must be brought on line Power companies have a dilemma in that they must have sufficient generating capacity to meet peak loads.  This is expensive.  To build new generation capacity when it will only be used occasionally is a nightmare to their accountants.

There are peak generation periods such as in the morning when everyone is getting ready to go to work or school and more so in the evening when everyone is home, the TV is running, mom is making dinner in the oven, it is winter and all the lights are on.  What the generating companies don't need is that at this peak load time you are also running the dish washer, cloths washer, cloths drier, water heater and so forth.  If these functions could be shifted to late at night when all the evening activity is over and the lights are out, then they could avoid having to build more 'plant' that will only be needed in peak hours.

This is where demand balancing comes on.  The power company has to find a way to induce us to use power whenever possible in trough hours so that we don't need this power in peak hours.  The inducement is simple.  The make power less expensive during trough demand.

They could simply make power less expensive for all uses as demand goes down but what is really the holy grail for them is to be able to switch on and off some of your electrical devices as needed to balance their base generation.

We need some hardware and soft ware to make this happen.  Here is an idea of how it will work.

You have special little units that you plug into your wall socket and then plug your device into the unit.  It 'talks' to your smart meter you have installed.  You can set the unit to come on at different prices for electricity and, of course, the power company, when they have a little excess power, will send a message down their lines that now power is at 24c, 23c, 22c and so forth as they need more demand to balance the base power they are producing.

You are unlikely to put one of these devices on your TV or stand up lamp.  If you do, the TV and/or the lamp will go off if the price for power goes above what you have selected. All these functions that are on demand.  ie that you can switch on and off as you want, you still pay the full power price of, let's say, 25c/kWh.  The only equipment you are likely to use these special plug in units for are your chothes and dish washer, any batteries you are charbing (such as your car or wall unit), your hot water cylinder and so forth.  On the front of the device will be a dial that you turn to the price you are willing to pay for the function in question.  But all devices are not equal.

With your car battery or hot water cylinder, the power can go off and on as the power company adjusts the price to use their base generation.  Your washing machine is something else.  Once the cycle starts, you want it to finish.  Otherwise you may have food baked on to your dishes or a wet mess in your clothes washer.  So we have another wee switch on the device which you can put in 'continue to the end' or intermitent.  Now we have one more problem.  For your dish washer, you will set the 'continue' function so once it starts it will finish.

A battery or water heater is something else again.  You may have set your car battery charging unit to, say 10c since past experience shows that you are likely to get some power at this price during the night but here we have a different problem. You want to be able to get to work in the morning.  so we need one more function in our wall plug device..

We have a timer on the device which you set so that full power comes on, say, an hour before you go to work.  If the battery is fully charged, it will not take any more power but if the battery is only partially charged, it will fill up your battery at the full cost.  Not to worry.  Even at the full day time rate, it costs about a third as much in fuel to drive a km than with fossil fuel.

Despite what you hear, power companies are more worried at present by the decrease in power demand.  People are putting in LED lights, factories are becoming more efficient and the power companies are seeing decreasing revenue.  The Electric car is a god send to them.  But they don't want to have to build generating plants that only work to take care of peak demand.  By shifting demand to off periods, they solve this problem and make existing generators much more revenue efficient.  For instance, when there is lot's of water, they can send more of the water through the generator rather than over the spill way.

This is also a great way to help solve the problem of intermitent generation of renewable energy.  Say that during the day, the generation of wind energy is unusually good.  They can lower the price for these special functions such as heating the water in your cylinder even during the day.  You get cheaper power, they sell the excess instead of wasting it and over all, less fossil fuel is used.  Win win all around.