Why did we evolve to die?

Second donor question (might as well get them out of the way when I’m still awake!):

“I would like you to tackle the question of why there is death in terms of evolution.”


What a good question! I should preface this by saying this isn’t my particular field of research, so I don’t know any relevant studies to cite off the top of my head – but I’ll try to explain death in general evolutionary terms.

So, why do things die? At first glance, it seems counter intuitive. The whole driving force behind evolution is “survival of the fittest” – fittest being those who produce the most viable offspring. Wouldn’t it benefit an organism to live as long as possible, continuously producing more and more offspring?

The roadblock is that organisms are constrained by the laws of physics. When you boil it down to the basics, living things are just really complex molecular structures and chemical reactions. And it takes a lot of energy to keep the entropy or “disorder” of a system from increasing (which is a vast oversimplification of the Second Law of Thermodynamics, I know – forgive me). That energy comes from things like the sun (woooo photosynthesis!) or metabolizing food (woooo citric acid cycle!).

Aging is basically the general decay of processes. As you build up more and more errors, things just don’t work as well. And there becomes a point where you make a trade off. Do you expend lots of energy to keep the old structure alive so you can inefficiently reproduce, or do you scrap it and focus on the newly made organisms?

Now, that’s a painfully anthropomorphic view of evolution, but it’s basically how it works. Keeping a decaying organism alive doesn’t significantly increase its fitness. In fact, it can even decrease its fitness! If you’re in an environment where resources are scarce (aka, pretty much every environment), you’re competing with your children for those resources. So resources you use to keep yourself alive could alternatively be going into making grandchildren for you. Sometimes it’s in your best evolutionary interest to die!

I think this can sometimes be an odd concept for humans to grasp, since we’ve recently been able to avoid nature’s typical limitations. Back in our savanna days, we’d usually get eaten or die of disease before aging took place. There was no evolutionary benefit to have mechanisms in place to stave off aging even longer when we’d usually die before getting to that point. Evolution doesn’t care if your joints start hurting or you don’t reproduce as well, because you wouldn’t have been around anyway!

And that’s what differentiates scientists from the rest of people. I find this absolutely fascinating, while I probably just depressed a lot of you by calling you decaying bags of molecules that nature doesn’t care about. Ah well.

This is post 7 of 49 of Blogathon. Pledge a donation to the Secular Student Alliance here.

Neanderthals and the beauty of science

A common creationist debating tactic is to sneer at science, saying something like “It changes all of the time! Scientists can never make up their mind, and often times they’re wrong! Why would you want to trust something that admits it could be wrong?”
And my response is usually to laugh, because that’s precisely what makes science so wonderful. We don’t stick with some dogmatic book even when faced with mountains of contrary evidence. We’re constantly trying to figure out where we’re wrong, so we inch closer and closer to an understanding of reality that’s based on…well, reality. Finding out we were wrong and correcting that mistake is the beauty of science.

I bring this up because a recent news story illustrates this perfectly to me. You may have seen the story circulating that non-African humans are part Neanderthal. Yes, some Neanderthals and Homo sapiens interbred back in the day!

At first I was a little confused, because I thought we had established this in May of 2010 when the Neanderthal genome paper by Svante Paabo’s group came out. But this new paper serves as a confirmation of that work, since it avoids one of the main criticisms of the study – that the human and Neanderthal DNA were cross contaminating each other. This new research only looked at human DNA, and compared it to the Neanderthal sequence. What they found was that about 9% of the X chromosome has a Neanderthal origin in non-African humans.

But if I go back to just April of 2010, everything was different. I was taking my 500 level Evolution class at Purdue, about to graduate. Our final project included downloading mitochondrial DNA sequences of humans, Neanderthals, and other apes to determine if humans and Neanderthals had interbred. From that data alone, the conclusion was an obvious “no.” And that’s what all prior knowledge had said up until that point.

I remember one of the last questions on the project being to explain how new information could potentially change this viewpoint. We needed the whole genome before we could definitively say Neanderthals and humans didn’t interbreed! Mitochondrial DNA is only a tiny part of the whole genome. We need more information because we’re so closely related. And what if only Neanderthal males were the ones mating with humans? Then no Neanderthal mitochondrial DNA would be passed on at all!

One year later, and my professor has to totally redo his lesson plans.

And that’s what makes science awesome.

This is post 3 of 49 of Blogathon. Pledge a donation to the Secular Student Alliance here.

Attention Seattle science fans!

The Department of Genome Sciences at UW (aka, mine!) is starting its summer public lecture series, Wednesdays at the Genome. Tonight is the first talk on “Recent adventures in human evolution” by Dr. Josh Akey. I did one of my lab rotations with Josh, and I can assure you it’ll be an interesting, fun presentation. Here’s some more info:

The UW Department of Genome Sciences played an important role in determining the sequence of the 3 billion letters of DNA specifying all of our hereditary information and is now one of the leading centers where the human genome is being interpreted and where new technologies for this analysis are being developed.

To share these advances with the public the Department of Genome Sciences hosts a ‘Wednesday Evenings at the Genome’ public lecture series each summer. These exciting discussions assume no background knowledge in genetics or other biological subjects and provide opportunities to chat with our presenters.

Presentations begin at 7:00 pm in the W.H. Foege Building Auditorium (S060) and will be followed by refreshments at 8:00 pm just outside the auditorium.

ADMISSION is free and the public is especially encouraged to attend!

SPEAKERS TO COME:

• July 13 – Mike Bamshad – Confessions of the genome: solving rare disease mysteries

• July 20 – Elhanan Borenstein – Meet your tenants: A genomic tour of your inner microbial zoo

• July 27 – Harmit Malik – Paleovirology: ghosts and gifts from ancient infections

Hope you enjoy it!

Why biologists shouldn’t be poets

Three Ninjas: what is it that proteins do?
Three Ninjas: they react w/ enzymes or something?
Three Ninjas: and proteins need to folded in a very specific way to interact with the right enzyme?
Three Ninjas: or…am i all mixed up?
Me: enzymes are proteins
Three Ninjas: oh
Me: Proteins do…everything
Three Ninjas: but if two people are an amazingly good fit for one another you could say they are like
Three Ninjas: proteins
Three Ninjas: folded just the right way
Three Ninjas: to
Three Ninjas: do something
Three Ninjas: ???
Me: there are enzymes that react with things, or structural things that hold the cell together, or things that act as signals, or things that regulate how other proteins are made or how much of them are made
Me: Well
Me: An enzyme binds a substrate
Me: Which is usually not a protein, but can be
Me: if you want to get really tecnical, an enzyme and a substrate that are an amazingly good fit would actually be really bad
Me: That’s what toxins are
Me: They bind to enzymes better than the right substrate
Me: So much better that they never unbind
Three Ninjas: i think that may not be the metaphor i’m looking for.
Me: So the enzyme is put out of commission
Me: Enzymes work in that they bind briefly, do something to the substrate, and then release it
Me: :P
Me: #overanalyzation
Three Ninjas: but proteins have to be folded into a very complex and specific shape to do their job though right?
Me: Yes
Jason J Brunet: GOOD ENOUGH
Me: rofl
Me: Goddamn musicians
Three Ninjas: :-)




And of course I think scientists can be equally good at creative pursuits (heck, I’m an artist too!). We just make very nerdy, scientifically accurate metaphors. Here, have a haiku:

Our love’s like poison

inhibiting an enzyme

I only want you.


…You should see the ode to fruit fly breeding I wrote for my creative writing class.

How big are the health benefits of circumcision?

When Dan had me on as a guest of the Savage Lovecast, one of the questions I fielded was on circumcision. I knew that circumcision had been shown to reduce HIV infection rates in at least one study, but I also knew the reduction wasn’t that huge. And frankly, that’s all I knew about the research, so I didn’t want to assert any more. I hadn’t read the paper, so for all I knew, it could have it’s flaws.

Turns out it does. PZ explains:

Now Salon has followed up with an article that suggests that circumcision may actually have some health benefits. I am not impressed. They cite a couple of incomplete epidemiological studies in African populations for HIV infection, and they come up with some astounding figures: a 50-60% reduction in infection rates. Wow, with that kind of advantage…sign me up.

However, these are deeply flawed studies. None of them were completed: they all abandoned the protocol and stopped the research as soon as preliminary results gave them positive values. This is like shooting craps and announcing that all your dice throws were practice…until you get a good roll, and then, yeah, that was the real deal. That one counts.

They all overstate their results. That 50-60% reduction was in relative rate, in comparison across the two groups. The actual calculated protection in absolute terms conferred by circumcision was a 2% reduction in the likelihood of infection. That doesn’t dazzle me, either, and given that the studies were terminated when they got their best results, I’m not persuaded.

And finally, give me a plausible mechanism for how circumcision would achieve these remarkable gains. Tell me how it is supposed to work. If it’s something to do with hygiene, it seems to me that better sex and health education should have the same or better effect than lopping off bits of skin.

Again, the jury is still out. So don’t be using this questionable study in the name of “science” to justify chopping off foreskin. And frankly, it would take a lot more than a 2% benefit to outweigh the concerns of autonomy in my mind. That’s not even touching on the fact that most people do it thanks to religion (which is bollocks ) or “tradition” (which is also bollocks).

And while I’m against circumcision, I’m also with PZ on his final paragraph:

I also say as I always have that I oppose circumcision, think it is a pointless and petty bit of suffering to put children through and ought to be discouraged, but I also don’t think it’s as hideously damaging as the obsessive nuts want to claim. Also, in the context of the original post, I consider it a prime example of selfish privilege to invade discussions of female genital mutilation, which does cause serious sexual and medical problems, with demands that we pay more attention to the lesser concerns of males getting lightly scarred penises.

What he said.

Picking on myself

I couple of weeks ago I mentioned that I was checking out UW’s mental health clinic, mainly because I wanted to facepalm at the Traditional Chinese Medicine/acupuncturist screener. I wanted to explain why I was going, for two main reasons:

  1. I don’t want people to worry about me, especially since it’s not that bad. I know I concerned a lot of people, including some who emailed me personally, so I wanted to let them know I was okay.
  2. Mental health has a lot of stigma attached to it because people are so embarrassed to admit anything is wrong. And frankly, it’s silly. We don’t tease or shame people for having bronchitis or cystic fibrosis or other physical ailments. And hell, mental health is still physical – the brain is an organ, not some disembodied spiritual puppet master. If we don’t mock people for being deficient in insulin, we shouldn’t mock them for being deficient in serotonin.

I was especially motivated by JT Eberhard’s bravery in so openly discussing his struggles with anorexia on his blog. So I want to do my part in breaking down that stigma, and talk about why I was going.

I don’t pick on myself. I pick at myself.

Dermatillomania, Compulsive Skin Picking, BFRB (Body-focused Repetitive Behavior). There are a lot of names for it, mainly because it’s only recently being recognized, and no one knows quite how to categorize it. It’s part of the Obsessive-Compulsive Disorder Spectrum along with classical OCD, anorexia, body dysmorphic disorder, hypochondria, and Tourette’s. It’s very closely related to the more well known trichotillomania, which is compulsive hair pulling. But instead of plucking hairs, I peel at the skin on my fingertips and lips.

It was weird when I finally realized there was a term for what I’ve been doing since I was a little kid. But it was even weirder when I read the description of the disorder. It was like a stranger has been secretly spying on me when I read this article:

What I am referring to is not the kind of little bits of rough nail or cuticle that everyone picks at or bites from time to time, nor is it the occasional blemish that people might squeeze or pick. These nail-biters continually bite their nails past the nail bed and their cuticles until they bleed and are constantly walking around with red, sore, and sometimes infected fingers. Those who pick their skin compulsively have their faces and bodies covered, at times, with red sores and scabs known as acne excoria, a self-inflicted skin disorder that resembles acne. The smallest pimple or blemish must be opened and picked at or squeezed, either with the fingers or another implement such as tweezers, needles, pins, toothpicks, etc. Numerous scars are often the result.

It’s funny. These particular examples sound gross and extreme to me because they’re not my particular tick. But what’s become normal for me is probably bizarre to all of you. I pick at the skin on the pads of my thumbs and fingers, and at my lips. It starts with a bit of dead skin that many people would pick off. But my problem is I can’t stop. You know how little kids like to put glue on their hands, let it dry, and then peel it all off? It’s the same fun – except I’m pulling off skin that’s not ready to come off.

Sometimes I go too deep, or go too far, and I’ll bleed. The result is bright red, scarred thumbs that look miserable and hurt to bend, or bruised and chapped lips that I perpetually blame on the weather. It’s clear that it’s a compulsion. You’d think the first time I made myself bleed I’d stop, right? But I’ve done it probably hundreds of times, and most of the time I can’t even stop while I’m bleeding – the job has to be “finished” until everything that can be removed is.

Why? The article gets it right again:

Another similarity between these problems and trichotillomania is that they seem to happen when people are in one of two modes. Some do it in an automatic way, as if they are in a trance and not really thinking about what they are doing. Usually, they are involved in some other activity at the same time such as reading, talking on the phone, working at the computer, watching TV, etc. For others, the deliberate picking or biting is their main activity at the time, and they will frequently interrupt other activities to engage in it.

There is also a strong commonality seen in the various purposes behind these three problems. At the most basic level, they satisfy an urge. Many report an almost uncontrollable feeling of needing to do them. Pulling, picking or biting also seem to deliver a pleasurable or relaxed sensation. When sufferers feel stressed, doing these things has a kind of soothing effect on their nervous systems, and reduces levels of stimulation. On the other hand, when they are bored or inactive, they seems to provide a needed level of stimulation to the nervous system. This probably accounts for why so many people who dislike doing them find it so hard to stop. It simply “feels good” at the time, no matter what the consequences.

If I’m stressed, I pick. If I’m bored, I pick. Sometimes I don’t even realize I was doing it until the damage is done. And worse, sometimes I realize I’m doing it, and my mind is screaming “Just stop!” and I can’t.

And as time goes by, it gets worse. Not in intensity, but in scope. The more I peel, the more the skin around the edge gets weak – so I then have more stuff to peel in the future. Which means what used to be a little pink spot near my thumbnail has crawled almost to the base of my thumb.

So that’s why I went to get help. I want to stop before my whole hand is a scarred mess, or before I take a chunk out of my lips that won’t grow back. I wanted to stop feeling ashamed when people asked what was wrong with my thumb (A paper cut? A blister? A skin disorder? Who was I kidding?). I wanted to stop freaking out about someone noticing it in a photo or when I shook their hand.

But I couldn’t do it with willpower alone. And I couldn’t do it with friends yelling at me to stop – that just made me feel even more terrible, which ironically would make me pick more. Though I did find a trick to stop picking at my nails – I cut them very short. Forgetting to bring nail clippers on a speaking trip is a tragedy for me.

But an unexpected upside to all of this? I get to geek out about the science behind it.

I know, always the nerd. But it’s intriguing. There’s a good sign this is genetic, which is also true in my family. And the hypotheses behind it are interesting:

Some have theorized that there may be that the same out-of-control grooming mechanism in the brain underlies them all. My own theory is that there may be some type of dysfunction of a brain mechanism that regulates levels of stimulation within the central nervous system, and that these behaviors represent an attempt to control these internal stimulation levels externally. People seem to pull, pick, or bite when they are either overstimulated (due to stress or excitement) or understimulated (due to boredom or inactivity). Many similar behaviors can be observed in animals who are kept in confined or unstimulating environments, or who live in stressful conditions.

The latter theory is supported by the fact that anti-depressants often successfully treat dermatillomania, though little research has been done on it yet. But if anyone ever wants a genetic sample, they know were to find me.

So, that’s that. I’ve always been wary of putting something out there that people can use as ammunition to show how crazy I am (or atheists are, or feminists are, or evolutionists are, or…). But it’s worth putting it out there to make all the other “crazy” people realize they’re not alone.

And come on. If someone wanted to call me crazy, they already have plenty of wacky things I’ve said or done.

“Wealthy, Handsome, Strong, Packing Endless Hard-Ons”

Greta Christina has a fabulous post over at AlterNet on “The Impossible Ideals Men Are Expected to Meet.” It’s a must-read. Not just because everything Greta writes is a must-read, but because it illustrates how sexism also hurts men. Which I’ve said a billion times before, but apparently not as eloquently since people still think I’m a hyper-sensitive libido castrating feminazi spider monkey.
Yeah, I didn’t get the spider monkey comment either, until I did a bit of research. Apparently the spider monkey mating system consists of females approaching the males! How utterly backwards. Those goddamn feminist monkeys.

Miss USA contestants on evolution

Beauty pageants, along with Hooters restaurants, are on my list of Things I Wish Would Drop Off The Face of the Planet. They desperately attempt to market themselves as something more than a superficial patriarchython by including a talent portion (“Look, I can play the piano mediocrely!) and an interview on a hot button issue. But listen to how the contestants answer “Should evolution be taught in schools” and you’ll see education and intelligence is not how you become a state representative (if you can stomach the whole video):

The thing that kills me is how many people think evolution should be taught just because people need to be exposed to different opinions. No, it should be taught because it is true. Graabbaelaelkeellele!!!

The upside to all of this? One of the few very-pro evolution contestants was the winner, with this response:

I was taught evolution in high school. I do believe in it. I’m a huge science geek. […] I like to believe in the big bang theory and, you know, the evolution of humans throughout time.


Maybe there’s some hope after all. Though I don’t blame these women in particular. The US is woefully uneducated when it comes to evolution – they’re just a product of our culture and terrible science standards.

EDIT: Miss Vermont wins at everything (13:00 in):

“I think evolution should be taught in schools because not everybody necessarily has the same religious background, and it’s important to have scientific facts about the world. And we do know that evolution exists, even on a small scale like with people, and with bacteria that are becoming resistant to drugs and what not. So, might as well learn about it.”

Hope!

I have rotten timing

I’m going to miss seeing this rotten-smelling flower:

The corpse flower unfurled its stately bloom at the UW Botany greenhouse tonight and was in full splendor by 10 p.m.


The stench was just starting to stoke up — the flower attracts pollinating insects by smelling like carrion — and had not yet reached its full power. Said to make the eyes water, it should reach full power in the middle of the night tonight. The greenhouse is open til 11 tonight, and reopens for visitors at 8 a.m. tomorrow, when the flower will still be stinky. The scent will fade, but the bloom still be well worth a visit all week.

And is it ever. A line of admirers snaked out the door to see the flower, with people waiting half and hour and longer for their chance to come in the steamy greenhouse, and climb a step ladder to peer inside the depths of the flower’s giant bloom. It’s that big.

Its outlandish, Alice in Wonderland appearance is the draw, figures Doug Ewing, who with a team of greenhouse techs at the greenhouse coaxed the flower into bloom after two and a half years of dormancy.

It could be years before the flower blooms again, so see it now!


Boooooooo! I literally work right next to this greenhouse, but I’m out of town for a week! Curse my timing. And opportunity to be a geeky biologist, lost.