Sunday, October 31, 2010

Why Are Women Pretty? Or, Why Do Men Like Porn?

Why isn't it men that wear makeup?
Why is that when you walk down the makeup aisle, the hair aisle they aren't monopolized  by products for males?
Why do department stores have a vastly disproportionate amount of female apparel and clothing?
Why is it that 87% of all plastic surgery is performed on women?
Why don't men go and get their nails done?
Why aren't men the ones that are most likely to have long, expensive, complicated, time consuming hair dos?  Why isn't it that men are the ones that take FOREVER to get ready to go somewhere?
Why isn't a diamond a guy's best friend?

Or, why is the human mating system so different from the vast majority of other animals?

Nearly across the board it's the males of a species that display.  They come in every shade and hue conceivable.  They hum, honk, buzz, vibrate, dance, sing, knock antlers, bash horns, strut, display...Their males are, simply put, pretty.

It isn't that human males don't have their own system of showing off--muscles, sports, status displays, material wealth, etc.  It's just that you'd kinda expect men to be prettier if they were like seemingly all other animals, but it's the females of our species that are beautiful, that preen, that strut and that display and not the males.

We seem to have everything backwards.


1)  Males that were picky had offspring that were more likely to survive and reproduce.

2)  Females that had certain attributes could communicate some perceived advantage and make them more likely to mate.

3)  There were enough females that males could be choosy.

4)  Being able to care for a child is much more critical to humans than it is to other animals.

Let's look at some of the human female attributes that men find appealing and parse them a smidge.  Hopefully, what we can learn is how that we're distinct from other animals.

Breasts - Why not start with the obvious?  We're the only ape, let alone mammal that make a display out of their mammary glands when they aren't lactating.  This, like several others to follow highlights a theme that child rearing is unusually difficult, costly, involved, prolonged in humans.  Our children are ridiculously vulnerable when they're born.  Wildebeest newborns need to be able to stand within a few minutes or they're abandoned.  Human newborns can't even lift their head or roll over and won't be able to walk for an entire year!!!  Animal Kingdom wide, that's shocking!

Nearly a third of a mother's resting metabolism goes into breast feeding.  So, men want women that can hack that Herculean task.

Hips - "I will greatly increase your pains in childbearing; with pain you will give birth to children." --Yahweh

Humans run a fine line between wanting speed and ease of locomotion, which has been linked to narrow hips and wanting wider hips for bigger brained babies.  Wide hips might be a more recent desired trait that shows a shifting emphasis on braininess.

Buttocks - Fat.  Glorious fat.  Energy reserves = successful pregnancies and ability to provide enough milk.

Taken to the extreme this produces a condition that's known as steatopygia.  

Eyelashes - why is having long eyelashes considered feminine?  That's an interesting question.  It might have something to do with youthfulness, which we'll talk more about below.  Or, maybe something to do not with eyelash length, but in eyelash prominence.  Maybe masculine foreheads that have pronounced brows might conceal eyelashes, so obvious eyelashes indicate feminine skull structures.  I have no clue, though...

Eyebrows - Why do women pluck their eyebrows to make them thinner?  Well, because big bushy eyebrows are masculine.  Why?  Because it externally communicates something about the internal hormonal balance.

Lips - We're the only ape to really have lips - red, puffy, voluptuous lips.  I've read some anthropologists speculate that this is some kind of throw back to the red, puffy, engorged vulvas that our ancestors were wild about (like a whole host of other simians have today).  That may or may not be, but it is possible to see this body part, like many, as a dip stick - it lets you know the health of the organism.  Moist (think lip gloss), red (rouge) lips contrast dry, pale or blue lips.  Doubtless, there is also a hormonal connection - it's known that higher estrogen levels = fuller lips.  Maybe it's yet another communication adaptation - red lips make for more obvious lip expressions.

Or, what if lips evolved simply for kissing?

To kiss.
To be kissable.

Sclera - This isn't specific to women, but it is interesting.  We're the only ape that has white scleras (the whites of the eyes).  Other apes have brown or dark sclera so as to camouflage their eyes.  The whitening of our sclera could have happened as another dip stick adaptation (white shows you don't have jaundice, bloodshot eyes or malnutrition of some kind) or as yet another adaptation to increase our expressive abilities.  One study showed that human babies look where the tester looks, as opposed to how tested apes look where a face is pointing.

Eyecolor - based on the mutation rate of certain markers it's estimated that the existence of blue eyes in humans is somewhere less than 10k years.  That fact alone combined with the knowledge that it's recessive should make it shocking to think that there are areas in Europe where the prevalence exceeds 80%.  So why the proliferation?  It's sexy.  Why is it sexy?  I'm not sure there's a simple answer, but possibly because it was an indicator of desirable genetic diversity (at least initially).  There are some psychological reasons I can't quite put my finger on yet.  Please look at this picture and comment your thoughts.  Blue does seem to accentuate where the eyes are looking (like at your eyes) by giving greater contrast to the eye's aperture.  That might be why they seem so piercing.  Brown, on the other hand seems more doe-eyed and innocent.

Hips to waist ratio - Hormones.  Men prefer women  with a waist to hip ratio of 0.7.  It indicates a desirable hormonal balance.  The difference between men and women's hips/waists can be a dead give away for drag queens.  Notice the below picture.  It's instantly obvious that's a male.  Why?   Because women's hour glass figure is important to communicate internal hormonal states.

You don't have to think twice about it.  This is a male's hips and waist.  Much about hormones is communicated through the shape of our anatomy.

Youthfulness - Young women can produce more children, better nourish them and have less chromosomal abnormalities.  This is not true for men who can actually become more appealing with age (think Harrison Ford and George Clooney).  Old men that are healthy and attractive often have high status (which takes time) and therefore resources and have proven that their genes came make it through the long run.  The emphasis for women is ability to care for healthy children.  The emphasis for men is ability to provide for a child and lack of mutations.

Hair (scalp) - More recently I think hair has communicated less about being healthy and disease free, which it does quite well, but more about personality.  This is a little bit of a pet theory, but I think our head fur (follicles only grow to a certain length and then die) turned into hair (doesn't stop growing) because of what it communicated about the person that could up keep it.  Think about it.  Hair can take an enormous amount of work. Especially long hair.  One of the easiest and clearest indicators of insanity is unkempt, wild, crazy, matted hair.  Maybe, just maybe, human scalp hair developed to show that a person wasn't crazy and could wash, comb, detangle, and fix up their hair.  Something like, if a women could care for her hair, which is time consuming and difficult, she could care for a child.  It's a thought.

I've included a clip of a women crying after getting a nastey hair cut.  I watched the rest of the show and to my recollection there were several women that refused to get their hair cut.

Women communicate with hair.

Works Sighted [sic] :

Monday, October 25, 2010

The History of Nice - Compassion in Human Fossils

We've been nice for a really, really long time.  It's basically the reason we're still around.  How else could we have survived ice ages, famine, skirmishes, hunted together, colonized every corner of the globe and communally created technology.  Take a moment to marvel at just a small sampling of the archeological findings that teach us the long history of human empathy, compassion, caring, affection, loyalty, commitment, and generosity.  We are the loving ape.

Where: Dmanisi, Georgia
Who: Homo erectus
When: 1.75 million years before present
What: toothless skull
Importance: this human lived many years without teeth and was most likely extremely decrepit.  He was being cared for; maybe even having his food chewed for him.

Where: Java, Indonesia
Who: Homo erectus
When: 800,000 years before present
What: severely broken femur
Importance: What happens to an animal if it brakes its leg?  It dies.  It lays there are slowly dies of thirst or starvation.  This human was cared for, feed, carried for months on end.

Where: Atapuerca, northern Spain
Who: Homo heidelbergensis
When: 500,000 years before present
What: hobbled spine.
Importance: he probably could barely walk.  Undoubtedly couldn't hunt.  Someone must have shared with him for years.

Where: Atapuerca, Spain
Who: Homo heidelbergensis
When: 530,000 years before present
What: deformed skull of child estimated at 8-12 years old
Importance: differences were accepted.  This deformed child was cared for for years until he passed on.

Where: northern Iraq
Who: Homo neanderthalensis
When: 60-80,000 years before present
What: crushed left orbit blinding that eye, withered and long since healed right arm most likely causing some paralysis, deformed right lower leg and foot.
Importance: couldn't see well, couldn't handle object well, could barely walk and yet he survived for many, many years with the help of a most likely loving community.

Works Sighted [sic]:

Avian Lungs Adaptation - Bewildering Breathers

Ultra cute ultimate breathers - Bar-Headed Geese
It's been estimated that bird's lungs work on average three times more efficient than mammals.  While a human may be strapped to the hilt with oxygen canisters climbing Mt. Everest at barely a crawl, it's possible for them to look above them and actually see a Bar-Headed Geese flying lazily over them (which is especially neat since it's thought that their annual migrations pre-date the Himalayas, hence the ridiculous journey.  Old habits. :) ).

How do they do it?

They cycle, not just pump.

Air enters their lungs (often on the up beat of their wings) and goes into several sacs at the back of the lungs.  The exhale takes that air through a lattice of capillary saturated branches that lead to a few more sacs that eventually exit the air (often on the down stroke).

The system seems rather counter intuitive and circuitous, but its strong suit is that it can create a constant flow of oxygen rich air to the blood stream.  Our arguably inferior spongy lung system pumps rather utilizing this odd circulation method.

Interestingly, there has even been speculation that dinosaurs had a similar lung system based on their rib/bone structure and the fact that some scientists have estimated that there were somewhat low atmospheric oxygen levels during roughly 100m years of the Mesozoic and they would need some very specialized breathing adaptations to obtain the massive size they did.

Works Sighted [sic]:

Sunday, October 17, 2010

Evolution of Acne

I had a bunch of ideas that I wanted to blog about this week.  Guess which one I picked?  The one that had the word 'evolution' in the title!!  teehee.  I just love thinking about the evolutionary origins of all the things that we take for, acne!

So, here's the question: what's the evolutionary explanation for acne?  What, if any, selective advantage did acne (or something that causes acne) bestow to its possessors?

I've compiled a short list of possibilities that I'd like for you to help me expand.

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The Sexual Repellent Hypothesis: some have said, although I'm skeptical, that acne keeps you gross enough during puberty that others will wait to mate with you until you're old enough adequately deal with the child. I can see a couple of problems with this.   First, acne happens more frequently in males, since a large trigger is testosterone which increases the sebum production (pore blocker and lubricant).  Males, evolutionarily, although they can have selective advantage in investing in offspring have little selective disadvantage in not trying to produce offspring.  So, our explanation of acne has to address the male problem and this one doesn't seem to adequately.

"It's Because I'm White, Isn't It?" Explanation:  Whites have more acne than non-whites.  So, how come?  Well, I've thought about this for a bit since a close friend of mine suffers from Rosacea (a reddening condition of usually the face).  Whites are white to absorb solar radiation to synthesis stuff like Vitamin D.  We feed off the sun.  The farther north one gets and the more clothing you wear means the whiter we need to get to make enough Vitamin D.  There's another strategy evolution can use, though - don't just make the skin whiter, fill it with more blood.  Is it possible that whites get more acne because our facial skin is flusher because it's trying to get enough blood to the surface to make Vitamin D?  Maybe.  It's a thought.

Dirt Don't Hurt Hypothesis: maybe we wash our face too much.  I don't know this to be true and I don't want to be the one to test it either, but it's a worthwhile thought.  We didn't regularly bath for most of our evolutionary history and maybe constantly removing the surface oil from our face (which is desperately trying to keep the face supple and emolliented to stay young looking) causes the production to go haywire.  Maybe.

The Lucky Loser Hypothesis:  some evolutionary biologists have proposed that maybe we go pizza face because it prevents us from getting murdered.  The argument simplistically goes like this, if you look good, you're a threat to other males' harems and therefore you get killed.  On the other hand, if your face looks like the surface of the moon then you probably aren't a threat for their mate to cheat on with.  Or, so they think!  This argument receives anecdotal support by a good number of monkey species that have beta and omega males producing more offspring than alpha males.  Zits are the perfect cover to sneak a mate with or to survive until your fully grown.

You Eat Yourself Pimpley Hypothesis: this argument says that it isn't an adaptation at all, it's a side effect of the fact that our diet has changed so drastically, so recently in our evolutionary history.  What are the two most recent additions to our diet?  Agriculture (by which I really mean grains) and dairy.  Both of which have been linked to increased levels of acne.  The study in the linked article talks about tribal Canadians and Japanese that broke out after being introduced to dairy.  It also talks about aboriginal people from Paraguay and Papua New Guinea that ate hardly any complex carbs and likewise had no occurrences of acne.  Now, I should say diet and acne is a highly debated subject, but one I think we should listen to.

Monday, October 11, 2010

Human Diet Hints from Evolution

Let's let our bodies speak and tell us what diet we should eat - Evolution's Fad Diet.

We have a relatively small large intestine (in comparison to other animals), which are used to house bacteria to ferment foliage (among other stuff).  That probably means that we didn't eat a whole lot of salads.  In the book Before the Dawn one of the most surprising things I read was that during the Ice Age humans probably only ate about a cup of greens a year! (Based on bone/tooth composition, which contains molecular markers for what they ate)  Don't take that too far.  We do have a significantly sized lower GI.

We have relatively small guts. That means our diet has been relatively high quality for a while - meats, fats, carbs from things like tubers, cooked matter.

No, that gorilla's not preggers.  They just have massive guts to break down the difficult to digest foliage they munch on.

We don't synthesize Vitamin C.  Our relatives did, though.  The section of our genome that used to has been identified, but it's garbled through mutation and since our diet usually had enough Vitamin C (most likely from fruit) we lost the ability.

Our appendixes are all but gone.  We don't need them to break down cellulose (plant pulp) anymore.

The cecal appendix (a through l) or appendix-like structures (m through o) in a variety of mammals. The cecum ⁄ appendix is oriented toward the top of each drawing, the distal end of the small intestine toward the left and the proximal end of the large intestine toward the bottom. (a) human, Homo sapiens; (b) Pongo pygmaeus, orangutan; (c) Lepilemur leucopus, sportive lemur; (d) Lasiorhinus latifrons, Southern hairy-nosed wombat; (e) Oryctolagus cuniculus, rabbit; (f) Phalanger gymnotis, ground cuscus; (g) Anomalurus derbianus, scaly-tailed flying squirrel; (h) Trichosurus vulpecula, common brushtail possum; (i) Bathyergus suillus, Cape dune mole-rat; (j) Atherurus africanus, brush-tailed porcupine; (k) Castor canadensis, beaver; (l) Microtus pennsylvanicus, meadow vole, shown with a partially uncoiled large bowel; (m) Phascolarctos cinereus, koala; (n) Ornithorhynchus anatinus, platypus; (o) Tachyglossus aculeatus, echidna.

Many humans digest lactose after infancy which means being able to drink milk had a very significant selective advantage (since it's so freaking recent - less than 10k years).  Places like the Netherlands which have traditionally farmed cows have lactose tolerance rates nearing 100% (certain pastoral African tribes have comparable rates).

Lactose intolerance distribution

We have small teeth and weak jaw muscles.  This is probably due to an increase in caloric quality of diet (carbs, fats, proteins) and the advent of cooking (which goes back several million years).

Our teeth or flatter and better for grinding in comparison to other primates which have teeth so jagged that they can't grind.

Pan=chimp, Pongo=orangutan

We don't synthesize all the amino acids necessary for life.  Where doest the term 'essential' in 'essential amino acids' come from?  Essential to all life?  No.  Only essential to humans.  Think about it.  We have to eat all the essential amino acids or we get quite sick, but other animals don't worry about it.  You don't see cows munching soy, yeast, rice with beans, meat, etc.  Their hulking lumps of bovine bodies make them quite well on their own.

Related topic:

Subcutaneous fat: some argue that humans have much more subcutaneous fat than other primates (subcutaneous is right below the skin as opposed to the internal types of fats).  Contrawise, others say nay and point to domesticated and caged animals as pudgy examples.  A greater need for subcutaneous fat could come from: variability in diet availability, aesthetic look of fat distribution (think booty and breasts, which are largely lumps of fat), or thermal protection during Ice Ages accompanied by a lack of body hair.

Post script:

Our bodies need vitamin B12, which we need from animal products.

Our bodies product elastase, which digest elastin, a connective protein in animal tissue.

Sunday, October 10, 2010

Virus Evolution

It's a topic one doesn't hear much on.  How did viruses evolve?  How did they come into existence and when?  My interest piqued below's a little net trolling I've done on the topic.

Virus Facts
Overview: Viruses aren't technically alive (life=metabolism, maintain homeostasis, possess a capacity to grow, respond to stimuli, reproduce and, through natural selection, adapt to their environment in successive generation).  They depend on invading other cells to reproduce.  They're essentially intricate molecular structures filled with genetic information to hijack other cells.

Scale:  they're one hundredth the size of a cell (on average).

Mimivirus - the largest virus

Relevance/Common Ailments Caused by Viruses: influenza, herpes, HIV/AIDS, chicken pox, warts, hepatitis, rabies, polio, and most everything else nasty.


Evolution of Viruses:   To cut to the chase, we don't know.  Why we don't know is almost as interesting as knowing, though.  They're too delicate to fossilize (although I guess the earliest virus evidence found was a plant abnormality from 200 mya).  Analyzing their genome doesn't help much either.  It's a tangled mess for a couple reasons.  One reason is the means by which they sometimes replicate their genome, the reverse transcriptase, is quite error prone.  Furthermore, they often sneak their genome into the genome of their host so the host cell will treat it like its own and build more proteins that build viruses.  It's probably not too hard to see how that can get kinda sloppy - lots of cross over.  That's part of the reason why we call them 'swine flu' and 'bird flu'; they literally contain bird and swine DNA.

There a couple of theories about how they might have evolved (and this might have happened several ways on multiple occasions).

  • They could have come from escaped genetic info that evolved to hijack other cells.
  • They could be trimmed down cellular parasites.
  • They might have coevolved early on in life's history and been an important part of the genetic exchange that catalyzed the genesis of life.

Prevalence: there are fifteen times as many viruses in the oceans as there are bacteria and archaea.  Woah.  They infect every branch of the tree of life and hence suggesting a very early origin (as does their diversity).

Relevance in Evolutionary History: viruses are an important source of horizontal gene transfer - viruses taking DNA from one organism and putting it in another.  It's been speculated that this may actually be a big part of evolutionary change.

Medicinal Treatment:  they're kind of like zombies - you can't kill what's undead (or more aptly, unliving).  So, we vaccinate/immunize to preemptively teach our body to recognize them and digest them when caught.  The tough thing about HIV/AIDS and other viruses is that the evolve so quickly and are so tricky about showing up on our immune systems radar.

Virus Infects A Cell from New Life Ministries on Vimeo.

Works Sighted [sic]: