How is sex like Obamacare?
No – I’m serious. How is sex like Obamacare?
…Good guess, but no – I’m not talking about the health and longevity benefits of sex later in life.
You don’t give up so soon, do you?
A: Sex and Obamacare both offer substantial benefits to the community, but they only work if everyone participates, and it’s not in everyone’s interest to participate.
Not so clear? Allow me to explain…
(What did you expect, I was going to start with sex? And trust that you’d still read through to the end?)
Insurance works (when it works) by sharing risk, providing a safety net that makes everyone more secure. But not everyone has the same risk, so it turns out to be a better deal for some than for others. To the extent that one can know his own risk in advance, people can game the system. Healthy people choose low premiums and high deductibles, while people who need more frequent medical services will choose the opposite. For the healthiest individuals – those who are young, don’t smoke or drive motorcycles or pursue rock climbing on the weekend – any kind of health insurance is a pretty bad deal, and it is in their interest to opt out.
Ross Douthat has a column in yesterday’s NYTimes about computer glitches that dragged down the rollout of Obamacare three weeks ago, but he begins by citing a New Republic article by Jonathan Cohen from last May.
Health insurance needs lots of healthy people to sign up for coverage. Their premiums cover the big bills for the relatively small number of sick people. So if the exchanges don’t enroll enough young, healthy people, insurers will have to raise everyone’s premiums. In the worst case, this could create what actuaries call a “death spiral”: Rising premiums prompt people to drop out, causing premiums to increase even more.
When Obama designed Obamacare, the greatest challenge was how to ensure participation. The obvious solution was universal coverage by a single payer, the system used in Commie countries like Great Britain and Canada and Japan and France and Germany and Spain and Switzerland and… Obama went to great lengths to avoid that, because it would be the end of fat profits for Aetna and Wellpoint. So instead of a one-sentence health care bill that welcomed all ages to buy into the present Medicare program, we have a 961-page document full of rules and exceptions and exceptions to the exceptions, and lots of wiggle room for insurance companies and their lawyers to continue charging exorbitant rates for Swiss-cheese coverage. Whether the Federal government has the Constitutional authority to compel people to buy insurance from private companies was a question posed to the Supreme Court two years ago, and it was resolved on a technicality.
…but I digress. The point is that the community has a collective interest in universal insurance, but for the strongest and healthiest individuals, insurance is a bad deal, so the community coerces their participation.
Just like sex.
…allow me to explain.
When I say the word ‘sex’, you’re probably thinking of male and female, reproduction, that sort of thing. No? Were you thinking of something else? Then you must be a biologist, because to a biologist sex isn’t about reproduction, it’s about combining genomes. Sharing genes. Sex is strongly linked to reproduction for us and almost all higher organisms, but it doesn’t have to be that way.
For bacteria, sex consists in plasmid exchange. Bacteria share genes promiscuously. Aplasmid is a little loop of DNA, and bacteria eat them like candy. They are constantly shedding genes (in the form of plasmids) for others to pick up, and taking in other genes that they find in the environment, with no regard to where the plasmid came from, or who owned it last. It’s as if they had no Mommies to teach them right from wrong. Plasmids are replicated along with the rest of the bacterial genome, and passed on to daughter cells. In this form, bacterial genes move freely not just between strains but also across species lines*. (This was discovered in the 1950s, when genes for antibiotic resistance spread through the bacterial world far faster than epidemiologists had anticipated.)
Protozoans (‘protists’) are much larger and more complex than bacteria, and, like higher organisms, they have two copies of each chromosome, but only during some phases of their life cycle. Protists share genes by sidling up to another protist of the same species, and dissolving the cell wall between them. They thoroughly mix their cytoplasm, and then their cell nuclei (with the genetic material) merge as well, and they mix up chromosomes, and mix up the genes within each chromosome. When the two protists separate, there’s no more telling which was (formerly) which. Each individual is now half and half.
This is called conjugation. It is a mind-bending process that disrupts our notion of indvidiual identity. It is also closely related to the way in which sperm and egg cells are generated in animals and plants (meiosis). But for most protists, reproduction is separate from sex. Every individual is perfectly capable of reproducing by simple fission of the cell (mitosis), and needs no other individual to do this.
There was a lot of evolutionary history before sex was invented, but it wasn’t nearly so interesting as what happened afterward. Sex was the best thing that ever happened to evolution. Sex promotes cooperation, and integration of whole communities of interest. It is sex that tamed the selfish gene and changed the rules, so that evolution wasn’t merely a race to see who could reproduce the fastest.
Before sex, it was every cell for itself. There was no motivation to cooperate, because only one cell’s progeny would survive into the future. Every other cell was a competitor, an enemy. After sex, there is a community encompassing a gene pool. Everyone has both an individual stake and a collective stake in the future. The individual stake is in getting more of my own genes into the communal gene pool. The collective stake is in seeing that the community survives and thrives.
What does this have to do with the title at the top of the page?
Sex made possible a life style that is far more resilient and robust in the long run, adaptable to different environments and robust to changes in circumstance. Sex ties together the fate of a community (the biological word is a deme) that shares genes. Sex also makes possible diversity, which protects a deme against extinction, and leads to far more rapid and efficient evolution into yet stronger communities.
But there’s a problem. It’s not in everyone’s interest to participate. In fact the “fittest” individuals – meaning those that can reproduce fastest – have no incentive to share the genes that make them superior. Hey – if they’re winning the game, why would they vote to change the rules? They would do well to opt out of sex, and just reproduce clonally.
…and if they did that, then the community would fall apart. Cooperation would give way to a selfish brawl, and the fastest reproducers would win. No complexity, no resilience, no evolvability.
Somehow, evolution has solved this problem. Evolutionary biologists haven’t a clue how this happened. From asexual reproduction (with gene-sharing on the side) to fully sexual reproduction must have been quite a complex transition, with no immediate fitness benefit, but only a very long-term reward for the community that pulls it off. It is a great and enduring mystery how this long-term communal interest prevailed over the short-term interest of the selfish individuals (for whom sharing genes was a bad deal).
Sharing of genes was made mandatory for almost all higher organisms, and even for some protists. In protists, the compulsion to conjugate is enforced with telomeres. Telomeres are protective tails on the end of each chromosome, and with each cell division, the telomeres get a little bit shorter. Eventually, this will lead to cellular senescence, and the protists will no longer be able to reproduce. The telomere is only rescued during conjugation, when an enzyme called telomerase is produced, that can restore the telomere to its full length. So if these protists don’t conjugate, they will eventually die out. [William Clark has a very readable account of this.]
And how is the mandate to share genes enforced in higher organisms? In most animals and plants, reproduction is tied firmly to sex. The individual cannot reproduce on its own, but only by finding another individual to share genes with. This solved the problem, and made sure that the fittest individuals would not opt out of the system, but would share their genes like everyone else. But how was it arranged? This linking of sex to reproduction, making sex a mandate, has been called the Masterpiece of Nature. No one knows how it evolved
The inexplicably dunderheaded mentality of the modern evolutionist
Since the 1920s when Darwinian fitness was first fitted to a mathematical formula, mainstream evolutionary scientists have postulated (i.e., they made an educated guess to see where it would take them) that fitness consists in leaving more offspring behind, faster.
(The exact formula is like a compound rate of return on investment, where the investment is one individual and the return is counted in offspring, which enter the formula as if they were a kind of dividend payment. This measure of fitness is called the Malthusian Parameter, designated lower-case r, and is computed according to the Euler-Lotka equation.)
Evolutionary theorists equate fitness to r, the Malthusian parameter, and base their models and their calculations and their predictions on this assumption all the time. They assume that the game of natural selection is all about making more babies, the faster the better. And yet, in another part of their brains, they all know that with two sexes, higher animals and some plants commonly sacrifice a full factor of two in r by being only one sex at a time. Hermaphrodites (like worms and slugs) have both sexes in the same organism. They have all the advantages of mixing genes, and add the advantage of being able to reproduce twice as fast. Twice as many offspring. Twice the fitness. Why don’t slugs take over the earth? Why aren’t we all hermaphrodites?
This is considered by evolutionary theorists to be an abstract mystery, a theoretical curiosity, a subject on which a few deep thinkers write clever papers year after year. But it is never – never! – a reason to question the fundamental assumption that “Fitness=Rate of Reproduction”, or that Natural Selection always operates to maximize reproductive success. It is never taken as evidence that Multilevel Selection is the name of evolution’s game, or that the perspective of the Selfish Gene is not the full story.
Next week, I plan to come back to the question: what blood factors do we lose as we get older, and what destructive blood factors appear in higher concentrations with age?
*to the extent that ‘species’ can even be defined for bacteria. Read more if you’re interested.
This article originally appeared on Josh’s blog here: http://joshmitteldorf.scienceblog.com/2013/10/21/how-is-sex-like-obamacare/