I was talking to the sibling figure about his lack of social life. Since it's agreed that he's the one with the 'people skills', it's a bit discomfiting. I said I had more friends at his age because I treasured the few that I made like precious gems.

The real reason? House full of pastries and kittens.

moss and gender

So if you're like me, you've often thought "Why am I not more like moss?" The possibilities of being hydrostatic aside, why are our gametes so pathetic? Why don't they live independent lives?

Note to self. Write science fiction with characters who can be completely dehydrated and revived. Also, with gametes that pull their own weight.

The cheery answer is that sometimes human gametes do. Recall high school sex education, where they explained that sperm contain a chemical that causes girls to fall in love? That is a lie and I did not know that until just now! I swear I have other examples!

Right. When the sperm and the egg fuse, some proteins from the gametes are still present. These proteins have startling effects on placental and embryo development. Sperm proteins determine the degree of implantation of the placenta- its ability to obtain nutrients from the bloodstream. (This is one of the major problems with egg fusion. No egg is going to encourage aggressive nutrient use on the part of the embryo. ) Egg proteins determine head size.

Oh, but that's not really gamete function at all- we want to anthropomorphize our gametes whilst they are still alive. Fine, fine, here. It's an article on how men will someday become extinct!

Except they won't. At least, not until everyone else does.

You'll have to excuse my terrible lack of citations here- all my science books are in storage. While Google is great, it cannot search for "that thing about 3/4 of the way through the book, next to the mostly green illustration". As a quick refresher- all eggs have an X chromosome. The chromosome present in the sperm (X or Y) will determine the gender of the embryo (female or male). Thus, most males have XY, most females have XX, and intersex persons have a dizzying array of possible chromosomal and hormonal variations. When fertilization occurs, there's a swap meet among the chromosomes- known as crossing over. This has less impact on the person who will get these genes than previously thought- you use all your DNA- but it makes a big difference to that person's offspring, because they get only the one copy. Oh genes, always thinking ahead.

The article above states that as Y chromosomes cannot recombine, single detrimental alleles are not exposed to selective pressure and eliminated. As such, most of the Y is nasty junk DNA, with only a cheery SRY (order: make testicles!) gene cluster maintaining some level of professionalism. (But there's evidence that they can recombine with themselves. Cool.) Since the DNA on Y chromosomes is crap, they are steadily shrinking. Soon they will vanish!

Well, okay. They'll vanish as soon as the SRY gene cluster moves to another chromosome. And all of the Y chromosome data becomes useless. Then males as we know them will vanish, as the genes that make them male will be on a different chromosome. (Italics for sarcasm.)

But we've strayed from our discussion about gamete adventures.

All living DNA is mutating at a steady rate. Since there are three times as many X chromosomes as there are Y chromosomes, X chromosomes have more time to experiment. (This is one of my favorite evolution facts. Larger populations mean a higher chance of an interesting mutation. Higher survival rates mean a smaller likelihood that the awesome will be lost due to random chance. This is why I am a liberal: because social supports might foster cool mutations.) Every so often, an X chromosome will decide that it can't trust a chromosome it can't recombine with- so all eggs containing this X chromosome will reject all sperm with Y chromosomes. Think of those amazon eggs, rejecting the possibility of becoming male! The excitement!

That's my gamete adventures Hail Mary pass. Sometimes eggs reject sperm with Y chromosomes. One of these shows up about once every... million years.

But let's think about the implications! The mutation can arise in a male, but after the first male passes it along to his daughters, there will be no males with that gene. (Well, until the magical circumstances that I'll talk about later.) Without males passing along this X chromosome, there can't be females who are homozygous for the trait. Thus, even if the gene gives you superhuman speed and the ability to eat rocks, it can't be present in more than 50% of all eggs. You'd end up with a male to female ratio of about 1:3. And what an advantage to the X chromosome! A 50% increase in available carriers! After a few generations as a zero sum gene, becoming 50% of all the mammals in a population!

But maybe a plucky sperm (with a Y) gets hit by a magic bolt of cosmic radiation. It's enough to knock off the DNA that marks it as a possessor of a Y chromosome, so it manages to fertilize an amazon egg. The resulting dude is a biological jackpot. Since his sons can carry the amazon gene, their daughters can be homozygous for that trait. Their sons will have the magic Y chromosome by default. Sperm from any other source is quietly selected against, because an ever growing portion of the population will be unable to bear sons with the old Y. Soon, everyone is a descendant of this dude. He wasn't even that awesome. (Everyone is also a descendant of the first person with the amazon X)

Man, that's another great science fiction short story. Oh, and platypus gender is freaky.

So this process has happened several times in our past. Every time, we've shaved a little bit more off the Y chromosome. Right now it is tiny. It's basically the SRY gene complex (testicles!) the SRY gene complex upside down, in case recombining is gonna happen, and about 50 million base pairs of mad ramblings. (The X has 150 million base pairs that code for things like blood clotting and color vision.) In the future, there will probably be further shaving of those mad ramblings. If the next amazon X recognizes the SRY complex as the marker of Y-ness, then we'll end up with that old 3:1 gender ratio. There can be no magic supersperm to remedy that, because the resulting person will have no sperm.

Unless the SRY complex is swapped to a different gene. See above sarcasm.

My, this is a long post.

What advantage do the other chromosomes gain by letting the X chromosome be picky about what sperm to accept? Well, at one time there were lots of human like things wandering around so it paid to be choosy about which sperm to accept. Mammalian hybrids don't survive very well- another way that moss is cooler than us- and since female mammals bear almost the entire cost of producing babies, X chromosomes in eggs were under significant pressure to reject dicey sperm.

One last thing. Over the last five million years, we've shaved 100 base pairs off the Y chromosome. The thousands of genes that once separated males and females have been reduced to less than ten. Human males are basically ladies with testicles.

C and I debate about this all the time. That's why I make him look at orangutans when we are at the zoo.

Dress Shopping

Amy and Bee and I went wedding dress shopping in Sacramento yesterday- Ryan was there too, although I am fairly certain he didn't know what he had stumbled into. It was a sodden miserable day, and we visited every freaking vintage store listed on yelp.

Long story short, they all sucked. I was looking for a fabulous cocktail dress, possibly from decades past. The first store resold disposable fashion. (So much zebra print.) The second had some fabulous coats, and many many beaded things- but I'm thirty years too young to shop there. The third store had been replaced with a bicycle shop, and the fourth....

Well, it sold secondhand lingerie. And bondage gear. And sex toys. And Zoot suits.

No dresses.

So we went to the mall and found a very nice dress. It's pale lavender. The saleslady cooed when I said it was for my wedding. I also tried on pretty much everything in the prom department. And I bought a suit, so I can fight with my mother about wearing jeans to interviews. Also, I am so epically bad at navigating Sac that I think Ryan hates me now.

I am convinced that clothes shopping is a trap meant to subdue and distract women from the real meat of things. My dream is to have C's wardrobe: endless stacks of t-shirts and underwear and jeans, with four neatly stored outfits for special occasions. I hope lavender dress 1a can become my second special occasion outfit. The suit is #3.

The wet woolly weather eventually trapped me in a little town along the I-5 corridor, where I spent the night in a cheap hotel watching TV and sweating in my skivvies. I'm not trying to kickstart a porn movie- apparently everywhere I go now has the heater modulator broken- set on 'high'. (This is also true in my car.)

I JUST CANCELED A JOB INTERVIEW SO I COULD GO WEDDING DRESS SHOPPING. SOMETHING IS WRONG WITH ME.

So ladies, (I believe I now have at least two lady readers) recall how in college you'd be talking to a dude about something charming and innocuous (like how to set your physics TA on fire) and suddenly you'd realize that you were in a conversation? The sort of conversation where being charming and diffident would lead to awkwardness about sex? And then you tried to break the world record for most uses of the word "boyfriend" in under a minute?

Right, at some point I decided to stop mentioning the boyfriend. It gave the impression that turning a simple, playful conversation into sad tales of emo woe was a perfectly acceptable wooing strategy, but I was sadly already taken. Also, after you snap at a man, you can go back to borrowing his notes. You can't do that after the significant other freestyle event. And I like to save the "O, if I were not enamoured of my love, I would dally with you, kind sir" for when it's kinda applicable- i.e, heavy duty harmless flirting.

So I saw the first dude I ever flirted with at the grocery store! We were from different cliques in junior high, but we used to bait each other shamelessly. We got about two minutes into a conversation, and then he dropped "wife" like six times. I smacked my head and said "Oh, I'm engaged! I just get so tired of all the wedding crap it slips my mind." (See, this is what I get for leaving "boyfriend" out of significant conversations. Also, least believable truth I've told all day.)

I think I may owe a few emo boys from Physics 7 an apology.

The Grandmother Hypothesis

So there seems to be mild to moderate interest in me rattling off about evolutionary psychology. I'm going to make an effort to separate my own musings from what I've learned- but in some cases, the whole thing's gotten mixed up. Thus, citations.

The grandmother hypothesis is a theory that addresses the conundrum of female longevity. Males can keep producing sperm into their second century, but a female giving birth after 50 is rare. Old Darwinism holds that if an organism can no longer reproduce, there isn't really any point in continuing to survive- so why do women live years and years past menopause- and on average, much longer than men?

One very popular theory is that grandmothers- and to some measure both sets of grandparents- increase the chances that children will survive. Another pair of eyes can keep someone from toddling into a sink hole, another pair of arms can carry around a miserably sick baby for a few essential hours, another pair of eyes can find some tasty treats, and another mind can remember and teach all sorts of skills.

There's a corollary to this theory; post menopausal women are frikkin' juggernauts. Since there's no longer any need to keep the body able to reproduce, they can drive themselves so very very hard and sacrifice everything for the good of their offspring. Recall how pTerry said there were entire civilizations based on the lifting power of little old ladies in black dresses? This explains why the only sport where women have an advantage over men is ultramarathons, where ladies in their fifties hold many of the crazier records. This explains why your mother is so much more productive than you are.

Everyone loves this theory, both because it makes intuitive sense and because it emphasizes those traits we admire in ourselves. Unfortunately, evidence is thin. It's pretty difficult to separate children who survived because grandma was around from children who survived because they had awesome genes, as did grandma- the proof that they are awesome is that she was still around.

An early experiment (not mentioned in the wiki article, but in my evolution textbook) looked at records of Canadian frontier families during the 19th and early 20th century. This is a wonderful combination of excellent record keeping with a horrible environment for children. As an illustration let's use the Little House books which are set immediately to the south; in the Dakotas, Minnesota, Kansas, and Wisconsin. After Laura and co. leave the extended family, everyone gets malaria- including the pregnant mother, and then a few years later everyone gets scarlet fever. They lose an infant during the scarlet fever, and an opportunistic infection gives the eldest child cataracts, leaving her blind. Then there's the long winter, where they nearly starve. The Ingalls had five children, four who survived to adulthood; one is blind, two are weak and sickly, and only Laura manages to reproduce. Shortly after her first child is born, her husband gets mumps and becomes sterile. (To her eternal fury, that child decided not to marry.) The frigid plains were not a happy place to raise a family. But this study found when a grandmother lived within 2 miles, there were on average .6 more children per family, and an increased survival rate of 11%. It's pretty solid evidence that grandmother presence and infant survival are at least correlated. (Oh, more Little House examples. While the original family has zero descendants, the siblings of Ma and Pa who stayed near Grandma and Grandpa have a couple hundred descendants today.)

So everyone was happy and excited, and decided to do more experiments. And blast, it doesn't seem to work anywhere else. The Hazda post menopausal women work very hard, and share freely with their offspring- but there's no increase in offspring survival. And there was a recent large scale study where living grandmothers are correlated with a decrease granddaughter infant mortality, but increase infant mortality in grandsons. There was some kerfluffel about murderous paternal grannies- clearing the way for granddaughters because they share more DNA. There's not a lot of evidence for it, but there isn't really another theory for post menopausal survival either.

Let's talk about the decreased grandson fitness study! Decreasing the fitness of someone who shares 23% of your DNA seems dumb, but I'm an optimist. I'm pretty sure LeeLee (my grandmother) preferred the brother to me. She quite liked the idea of a clever granddaughter who wanted to become a botanist, but she had real affection for the quiet child who was a dab hand at bridge. (Tiny, tiny sample size. Please yell at me for bad science.)

Here's my sciencey rationalization that explains the results: say you have a gene for resistance to viruses or mental alertness or extracting rare nutrients. There's a really common version that works fantastically 99% of the time. There's a rarer version that works 90% of the time. If you have two copies of the common one, you'll be just fine 99% of the time you need to use that gene. If you have two copies of the rare one, you're stuck with 90%. If you have both- called heterosis- then 99.9% of the time, you will win. (By win I mean not die.)

What does this have to do with the previous study? Well, if this gene is on the X chromosome, grandma can be heterozygous at our theoretical allele and probably live longer than average. If a granddaughter is also heterozygous there should be a similar boost in survival. However, some grandsons could have the less awesome version of the gene, and are sadly missing a second copy of 1/26th of their DNA. It sucks to be a dude.

I think my next post will probably be on that.

too long, didn't read

My brother has his first internship that's prep for a white collar job. I end up proofing most of his communication with his supervisors because we're neurotic and I have no life.

I cannot convince him to keep his e-mails short. I hold the shorter the message, the more likely people are to read the whole thing. Five sentences max. Five sentences and a checklist. He decrees that he must explain every turn of his thought process- double check for miscommunication, avoid sounding curt and rude, give the intuitive scope of his project.

Say it with me. Too long, didn't read. Chatting is for personal communication.