The Birds and the Bees...Literally.

Chapter 2 in The X in Sex

I mentioned in an earlier post that I was reading a book called "The X in Sex". Well, I finished it. And I know I say this about almost every book I read (and it's true!) but this was so interesting! Plus it was well written, and even funny in parts....I mean who can't appreciate a chapter entitled "The Duke of Kent's Testicles?" It's even more amazing to me because the subject of the book (minus the portions about testicles of course) is actively, at this very moment, doing all the things that I am reading about...inside every cell in my body. It's weird feeling to learn about my insides, and understand myself in such a way. I mean, there are processes going on in my body right now that...even with the aid of a book, I'll probably never understand. But somehow it's still me. How could I not know myself?!? Ha ha...It's just so weird...and awesome. I love it.

I learned so many cool things from this book that I am afraid if I try to cram them all into one blog it will be...sort of long and unfocused. So instead I am going to try to break it down into a few segments.

But before we start talking about the familiar males and females, X and Y and all of that, I thought it might be worth while to go into a little more depth on the multiple ways a living thing can create progeny. Bear with me if it seems a little redundant to the last post about this book. I'm going to try to be a little more specific.

Sex happens to be the one us mammals and many reptiles and birds use, but it is by no means the only (or even most efficient) way to produce offspring. And some of them are pretty incredible, at least as strange as our own way. As most of you probably know reproduction is broadly divided into sexual and asexual.
Asexual can be broken down into parthenogenisis, binary fission, budding, fragmentation and many other, but more obscure methods.
Fission and budding are mostly accomplished by bacteria, some viruses, and plants, and while they are interesting in their own right (and have many advantages), I'd much rather focus on parthenogenic species, because they are just so neat. They are animals that can reproduce without a male (or an opposite sex). Primarily they are mother/daughter species (although some can produce males once in a while, or be all male species) where the genetic material from the mother is passed directly and completely to the daughters. The classic pathenogenic species are aphids. But science has now discovered that some bees, lizards, hammer head sharks, Komodo dragons, and boa constrictors also reproduce this way!
When we move onto sexual reproduction things might become more familiar because there are boys and girls, but the methods of producing the XX/XY or ZZ/ZW (in birds and reptiles) can be totally foreign still! Besides our "normal" way of reproducing there are hermaphrodite species, like snails and many amphibians that can have both male and female sex organs at the same time (and fertilize their own eggs) or have the ability to change from male to female during their life cycle. Some species of frogs, when the ratio of male to female gets disrupted, can convert many of it's population to the less dominant sex to balance things back out again!
Or there is what is called "external fertilization" in contrast to our internal method. Salmon do this. A female will lay her eggs in the water, and a male will come by later and fertilize the eggs, and all the mating happens outside the body of the female.
Even when we finally get to talking about sexual reproduction where there are distinct males and females and the females are internally inseminated by males, the process can be wildly unfamiliar.
Humans (and all mammals) use genes to determine sex. XX and you have a girl XY and it's a boy. But there are many sexual species (with males and females) who don't use genes to determine sex! What do I mean? Well, here are two examples.
Bonellia is a kind of worm that lives in the ocean. They have males and females, but it is not genes that determine the sex of the offspring, rather it is the environment. The female creates sexless larvae that float around in the ocean. Eventually they drop to the ocean floor, and it is here that they decide what sex they will become. If the larvae falls and there are no other Bonillia around then it will become a female and root. If the larvae falls and there are other Bonillia around then it becomes a male, burrows into the side of the larger female, and essentially becomes a symbiotic...testicle! (Angler fish, as I mentioned before, also have a symbiotic relationship with each other.)
A second example is that of the Nile Crocodiles.They don't use genes or environment to determine sex, they use temperature! The sex of the baby crocks is determined by the temperature of the eggs during the middle of the third incubation period. If the temperature is above 34.5 degrees C or below 31.7 degrees C then the offspring will be female. But if the temperature falls within that 4 degree window, the babies will be male!

Often times we view the natural world with the idea that it is somehow perfectly designed, that there is an methodical simplicity in it, but I disagree. Especially when it comes to reproduction.  It seems to me life will try anything and everything. Males/females, females/females, males/males, male-females, males-then-females, non-sexed to sexed, non-sexual, clones, spores...etc. It reminds me of the game Boggle, where you use a discrete number of  letters to make up as many words as you can. So life has done with reproduction. Using the building blocks available, life tried every combination it seems,without bias. And the ones we are left with are the ones that worked better than the other possible combinations that are no longer with us.
Our human sexual reproductive ways have many advantages (primarily genetic diversity) and it is truly amazing how our bodies reproduce, but our strategy is far from perfect, and far from being the only way to get things done. And there are many weird, dramatic, and often unfortunate concequences embedded in our chosen methods. I will begin to discuss those in the next post.
But the take away point here is that there are pros and cons to every method of reproduction. None is perfect, none is flawless, and most of them are not even ideal. But the one thing they have in common (and the only thing they need to be viable forms of reproduction) is that they do in fact create survivors. You and I are one of them, and so is every other living thing on earth. Groovy. Yay for reproduction!

Who's Your Great-Great-Grand-Daddy?

The other day at the gym I was surprised to see an issue of the journal Science among the normal fitness/body building ones in a basket in the lobby. I was a little early for yoga, so I sat down for a quick read. As I thumbed through some of the shorter articles I came across one discussing the recently-complicated family tree of we humans that was pretty neat.
For the past 100,000 years or so we have been tooling around the earth doing our "thing" which involved learning, creating culture, reproducing and all that fun stuff. But many of us forget (or maybe never realized to begin with) that we weren't the only folks around at that time. In the past 35,000 years there were Neandertals for one, and archaic humans called the Denisova hominin in addition to ourselves. And if you go back to the beginning of that 100,00 years when Homo sapiens emerged there were probably a few of our older ancestors still running around, like Australopithecus sediba and so on.
Anyway, for almost the entire history of anthropology it was thought that we humans never mated with any of our  early neighbors. But DNA sequencing is turning that idea on it's head. Recent study comparing modern human DNA to Neandertal and Denisovan DNA has produced the following results:

• Eastern Europeans and Asian people have inherited 2%-6% of their DNA from Neadertals.
• Peoples of Southwest Asia have inherited about 5% of their DNA from the Denisovans, and another 4-6% from Neandertals. (Another study found this same distribution in people in the Philippines, Southeast Asia, and Melanesia.) (That's about 10% total!!!)
• Denisovan DNA was found in Australian aboriginals
• Three isolated African groups inherited DNA from an unknown archaic people, long after modern humans arose.
• It has been discovered that over half of the human genes that code for leukocyte antigen proteins, (i.e.the ones that help detect pathogens in the blood) came from some or another "archaic" human.

I guess maybe I should point out before closing what is meant by archaic humans. They were still Homo but their DNA shows them to be distinct from us modern humans. They appear to have evolved from the same ancestors as Neandertals, but were closely enough related to humans to be able to reproduce.

Note: You may notice that I spell Neandertal with a "t" rather than a "th". I believe the "th" is the American version, but in all of my readings (both in school, and in scientific journals) always uses the "t" version, and I figured if it's good enough for Science it's good enough for me.

Glowing Kittens

Glowing Kittens! (image from discovermagazine.com)

        Well, it was only a matter of time before scientists "made" kittens that glow as well as puppies. These adorable little guys are being used to study feline HIV (which apparently can also infect monkeys). The virus was inserted into the eggs of the mother to see whether the kittens would be immune to feline HIV afterward. In order to tell if the virus actually made the transfer it was tagged (i.e. inserted into the virus) with a bioluminescent gene from jellyfish that would glow under a black light. The 'glow' was used to confirm that the virus indeed made it into the kittens, which is obviously a necessary control on the experiment. Isn't that ingenious? Oh science, you've done it again!

Sphincter Says What?

This has been my week for learning  semi-gross, yet strangely fascinating facts about biology. So just today (yes I can be cutting edge once in a while) I read an article about sphincter cloning.
It might be hard to believe, (and to be honest I have a hard time accepting the fact that I totally believe you can  replicate butt holes but still doubt whether or not wearing white after Labor Day is acceptable ) but scientists have successfully cloned a mouse sphincter! And while I am certain going from a mouse to a human is an exponential process (literally) it's a great achievement.
All poop jokes aside, (and I have a ton) it's really an amazing thing. Many people think the worst thing that can happen to you as you get older is to get wrinkles, or get grey hair. But there are much more embarrassing prospects that can occur with aging that can greatly reduce your quality of life. And the fact that there are folks out there looking to improve my prospects when I'm 70 is something that I will not take for granted. It's a modern day miracle.
Read here for the full story!

Starvation, Stress, and Fetal Development

I have been listening to a really interesting (and somewhat confusing) lecture series on human behavioral biology and have really enjoyed it so far. Out of all the interesting and unbelievable things I am now becoming acquainted with, there was one that I thought I'd share here. In a lecture called "Behavioral Genetics I" I learned about the pre-natal environment, and the lasting effects that things like stress and diet (of the mother) can have on a fetus while still in utero. Even though both stress and metabolic problems (or whatever you want to call them) are often passed from generation to generation (for about 3-4 generations being the average) neither is a genetic trait, i.e. they are not transferred to the offspring through DNA. These are examples of non-Mendelian inheritance, or non-genetic inheritance. They are circumstantially transferred from mother to fetus (and through subsequent generations) through some specific situation or as a result of some outside influence. I find that totally fascinating!
The following paragraph comes from a study on people who lived through the Dutch Hunger Winter in 1944.
For example, I guess it's during the third trimester that a fetus develops its metabolic pace, I guess you could say. That is to say it is during the last trimester when the fetus sort of (metaphorically) takes stock of how often and how much nutrition they are getting from mom and they adjust their metabolism, (which remains fixed ever after for the rest of their life) to most efficiently absorb calories. The staggering affect of this is that if the mother is starving, or otherwise not eating properly, or overexercising (so her body needs more calories than she is giving to her baby) then the fetus develops a very thrifty metabolism that can eek every last drop out of its caloric intake. If the mother eats normally, then the fetus develops a metabolism that is more normal, i.e. doesn't try to hold on to every calorie that enters the body. What that translates to down the road (in western society mostly) is that in the first case, there is a very high chance that the fetus will be obese, and will develop diabetes later in life, because it's body is tuned to absorb every last calorie, and once they are introduced to a western diet McDonald's and ice cream, their body can't process it normally. In developing nations this is actually adaptive because starving mothers there are more likely to raise their kids in an environment where there is little food and they need that frugal metabolism to survive.
It's just really incredible to think that during that 3 month window, way back when, inside mom, the amount of nutrients she consumed while the fetus was developing, could have lasting effects like her offspring having a lifetime battle against obesity.
Likewise, stress in the mother during pregnancy can alter the amount of stress hormones produced by her fetus and lead to things like depression and increased susceptibility to stress later in life. It basically works like this; mom gets stressed, she releases glucocorticoids into her blood stream. The fetus then absorbs them and as a result, develops a smaller than average brain, thinner cortex, which in turn makes it harder for the fetus to produce the hormones that block glucocorticoids (i.e. they can't turn off the stress response, after the stressful situation has ended). This leads to depression, anxiety, etc, And when the offspring get pregnant (years later) the cycle continues through the next generation.
So I guess the moral of the story is if you get pregnant, eat a lot of (healthy) food and whatever you do DON'T FREAK OUT!

I guess I should note that there are some scientists out there who disagree with the conclusions reached above. There were other studies conducted that produced different results. However from what I've read, it seems the differences are due to inconsistent controls from experiment to experiment. (For example, a similar study was done on Russian babies, and the results showed no correlation between mothers starving and obesity of fetus later in life, but in the Russian case the study covered the average of all babies (not just the ones in the last trimester), and the fluctuation in food supply was much more gradual than in the Dutch Hunger Winter study.)

Consile This

I just started reading Consilience by Edward O. Wilson, And when I say "just started" I mean I am 10 pages in. The basic idea, from what I've gathered in the pages I have read so far, is that the author believes eventually science will merge with social science and everything will be explained and made clear through a singular set of laws. Philosophy will cease to exist, because every aspect of human endeavor will play by the universal rules, and so become understandable, testable, and predictable. At the moment I haven't the slightest idea of how this might happen, but it appears by the length of his book that Wilson has come up with a solution. I was going to read more, but I suddenly felt more like writing and thinking. (Not that reading doesn't require thinking, but I mean pondering/thinking not analysing/thinking.)

I have been toying around with a similar idea (or maybe the same one?), although I never gave it a name, whereby every human action and decision no matter how ridiculous or surprising might be understood in a fundamental way if viewed through the active mechanism of evolutionary progress. It is the idea that no matter what we do, no matter how badly we want to be in control of who we are, at the heart of every action that we are capable of performing we will always find that we are doing what 3.5 million years of evolution is telling us to do. From that point of view, psychology would not be the study of why humans act and feel the way we do. We would already know that. The study would focus rather on figuring out how our actions and feelings are satisfying our (to borrow a phrase from Star Trek) prime directive of evolving.
Even the actions of the insane and mentally ill could be "understood" because if there is some physical ailment that interferes with their ability to function then it stands to reason that their judgement and decisions would be faulty because of it (and not a their own fault). But what would that do to our legal/justice system?

The question becomes if everyone always does what nature intended, then is everything hopeless? If everyone since the dawn of consciousness (and before it for that matter) is doing what evolution wants them to do, then you could argue that the reason we have not achieved things like world peace is because we were never meant to. That's as good an example as any. At first glance killing each other appears counter-evolutionary, but maybe there is a reason we have been fighting each other for centuries. One might argue that it has been our primary means of population control. Our instinct to take over what others have instead of live peacefully side by side could be interpreted to be a result of the fact that evolution has shown that in the long run it is more beneficial to have your neighbor dead than living next door with his 50 offspring and a dwindling supply of land and food.
A dog can learn to open a car door, but it can't speak English. A dog is limited by what it is. Maybe we are limited in the same way? We might learn some cool tricks and have some nifty ideas, but maybe we lack the ability to change the world we live in literally because we are human. I don't know, does that sound depressing? Who cares if it's depressing, what if it's true? Science and philosophy, thought and instinct all rolled into one smooth reality.

Like I said, I haven't read the book yet, so hopefully whatever Wilson has to say on the subject is encouraging and not defeatist. I am already confused! Any thoughts?

The Schwarzenegger of Cows

She ain't your typical bovine. Belgian Blues, like the ones pictured here, have a (naturally occuring) faulty copy of the gene that regulates muscle development causing their muscles to grow faster and much larger than normal cattle. They are now purposely being bred by farmers as meat cattle. Holy double cheeseburger!

Monks, Peas and Dirty Knees

I am currently reading a biography of Gregor Mendel, the "Father of Genetics" as he is called. The book I am reading is called "A Monk in the Garden" by Robin Marantz Henig. It's really a great read, and I recommend it to anyone interested in learning more about this Augustinian Monk, and his experiments. It's his life that interests me more than his research at the moment. I already know what he did, and how. I was curious about learning more about who Gregor Mendel was. Here's what I have learned so far:

It appears that Mendel had some sort of condition throughout his early and middle life that left him bed ridden for weeks to YEARS at a time! I am no doctor, but it seems to have been more psychological than physical. Maybe today it would be diagnosed as a sever anxiety disorder or chronic depression. Basically Mendel couldn't handle any stress, and when he was confronted with it he just fell apart.
In retrospect he was perfectly suiting to living in a monastery and tending generation upon generation of peas, because there really isn't all that much (besides frost maybe, or the possibility of burning in hell) that should stress out a gardening man of the cloth.

His life at first seems simple and confined. After all he was a monk living in a monastery. But at the same time on a certain level it appeals to me in that life was predictable, and known, and he didn't have to worry about paying the bills, or providing for his retirement, or any of the million other things that most of us deal with on a daily basis. (Maybe I am just saying that because I am under a lot of stress right now?) Whatever the reason, reading about Mendel's lazy days kneeling in his garden pollenating and picking his beans, his afternoons in the greenhouse sitting and counting and sorting them, or playing chess, or just thinking, the world class meals he was served three times a day (and a snack!)that he ate without ever having to step into the kitchen or wash a dish, the evenings in the Library (or the hall that held all the books that the monks read that was behind the library)sitting in an overstuffed chair perusing any number of topics in their extensive library....(it goes on) feels fairytale like to me, and I am fascinated by the idea of it. Doesn't that sound like heaven? Except for the whole celibacy thing, the fact that the monastery apparently was freezing year round,and that he had to sit through a church service everyday, I believe it sounds perfect.(I guess I should note that Mendel did teach classes at a school in Brunn during the week, but even so, it still seems like a pretty good life.)
I wonder if given such time and circumstances I could come up with such a breakthrough theory of scientific importance?
Probably not, but boy would I love the chance to try.