There must be something wrong with the link between my science gland and the pleasure centre of my brain. I mean, normally a story like this would have me a-jitter with excitement. But for some reason, it fails to enthuse me.

So what’s up? Scientists have created (by means of an ingenious combination of intelligent design and natural selection) RNA molecules that can replicate. Except, well, personally I think “replicate” is rather a strong term. They copy themselves by assembling two smaller strings of RNA, rather than directly from nuclear acids (PZ Myers explains the process here). To me that doesn’t seem like that big a leap forward in the RNA World research. It’s one step in a long chain that might end up with something of supreme awesomeness - but we’re not there yet.

Cool stuff, but nothing I’d get overly excited about. (Or maybe I’m just stressed about the paper due on wednesday and having to turn my apartment upside down in anticipation of the new bed. Hard to tell with these things.)

evolution, rna

One of my most popular posts on this blog is Answers From an Atheist, where I answered a load of questions about atheism. In the same vein, I recently received an e-mail from a christian creationist who said he had encountered this blog, and asked if he could “show me some things”. Shrugging off the slight creepiness of that question I responded that I’ll be happy to spar with him so long as the “things” he wanted to show me didn’t come from Answers in Genesis. I also requested permission to post our exchange on my blog. He didn’t say no, so, here we are.

Before we start: If anyone wants to take me to task for being condescending and snarky, go right ahead. I am being a bit condescending and snarky. This guy engaged me via e-mail, rather than on my blog, which to me implies he has something really important to say. He wanted me to take the time to listen to his arguments and respond to him personally. I agreed, hoping he actually had something interesting to say, and then he sends me these confused rhetorical questions. Although I try to maintain an upbeat, friendly tone throughout my response, I can’t help if some snark poured through as well. I’m sure he means well and I hope he gets back to me (although I can imagine it’ll take him some time to get through my rambling), because I do enjoy a good verbal one-on-one.

Oh and if anyone finds fault in anything I say, please call me on it. My response was hastily written and not particularly well researched (although I’ve obviously come across the subject of the origin of sexes many times, I haven’t read anything in-depth about it recently). I don’t think there’s anything ass-backwards about it but one can never be too sure.

And, finally, if you’re a non-atheist or non-biologist with questions, please do ask! I’m no expert on either area but I love pretending to be one…

Are you willing to seek God’s existence? I certainly hope you do, because there IS evidence pointing to God.

This question is unanswerable except in the form of counter-questions:

1. Which “God” are you talking about? One of the many christian versions? Or any of the abrahamitic ideas of “God”? Or shall we branch out and include the gods of all living religions? Maybe, for good measure, the dead ones as well? I always thought grecian mythology was a hoot.
2. What evidence?
3. Do you realise it’s rather weird to ask someone to “seek” something before you present them with the evidence? Seeking God’s existence presupposes that he exists. Since I have no such presupposition, I look at the universe without religious eye-glasses, and see no evidence.
4. What do you mean by “willing”? I’m not unwilling to believe in god, I simply can’t believe in something that goes against the evidence. Are you “willing” to investigate the possibility that god actually doesn’t exist at all? Because believe me, the evidence is much better!

Do you believe the big bang formed the universe?

Since that’s the informed consensus of contemporary physicists, yes. It’s not my area of expertise so I’m happy to leave this question in more capable hands. Just like physicists are (for the most part) happy to leave the question about the evolution of life into the hands of biologists. Unfortunately, theologians often seem to do neither…

If so, then how come big bangs tend to cause detruction rather than creation any more?

I’m sorry, but what exactly do you think a “big bang” is? You seem to be confusing it with “explosion” or “loud noise”. As far as I understand it, the Big Bang was named such because it’s an easy visual - everything springing into existance at once, in a boiling hot soup of matter eventually coagulating into stars and planets. It makes our puny human minds think of explosions. But that doesn’t mean it actually was an explosion in the regular sense of the term. Besides, since the Big Bang entails something coming from nothing, and “something” is already in existence, the Big Bang can’t happen again, by definition - not in this universe, at any rate.

If the universe was formed by a big bang, things should still form by a big bang.

Non sequitur. If you were formed by your mother and father mating, you should still be forming by your mother and father mating. No? No. Something happening once does not necessarily mean it can and will happen again.

If I went to a junkyard, and got some old metal, and springs, then put them into a box, and shook it for a day, week, month, then a year, and all of a sudden BANG! A watch is formed by random chance, would you say that is logical?

“Logic” has nothing to do with it. This is about probability. And no, the probability of a watch being formed in that fashion is extremely low. What does this have to do with anything? I suspect that you think you’re saying something really smart about either evolution or the big bang, but I’m afraid you’re way off target - although I can’t say much about the big bang (as I said, I’m not a physicist), I can tell you that evolution is not purely driven by chance. Please look up “natural selection”.

One last question for now, What about reproduction? Let me explain: Almost all living organisms have to reproduce with one male, and one female. One connot carry life without the other. Which came first according to evolution? If the male evolved first, he could not have reproduced without the female, and vise versa How is it that both the male, and the female both randomly came into existance, ad they both evolved individual, and complex reproductive systems?

Ah, now, this question I can actually answer (to the degree that anyone can, I suppose)! See, reproduction is a very interesting part of life and its evolution, and one biologists spend a lot of time on (insert obligatory sex joke here). However, my answer will by necessity have to be rather brief and unsatisfactory, seeing as I don’t have time to 1. plow the literature for all the extra interesting tidbits or 2. write the series of books the subject deserves. Especially seeing as it’s already been done.

First of all, I’m glad you say “almost”, because … well, even with that caveat, you’re still completely wrong. Most living organisms are bacteria, and they do not have sexes - although they do carry out a fair bit of DNA exchange which may be seen as a sort of sexual behaviour. And among the sexually reproducing organisms, it’s still the case that when environmental conditions are stable, males are pretty much superfluous, so the idea that “one cannot carry life without the other” is also faulty. We’ll get to this in a bit.

So, how did sex start and why? First let me just say that obviously, we don’t KNOW. I’m going to present a hypothesis to you that is perfectly plausible, but I’m not saying it’s the gospel truth. The puzzle of how sex began is a big one, a whole field of research in itself. That you expect me to answer your question just like this says something about your disregard for the complexity and intricacy of biology as a research discipline.

Anyway. At some point, organisms evolved an ability and propensity for exchanging DNA with one another. What’s the benefit? According to one hypothesis, the benefit is evolution itself. Because the environment an organism and its decendants exist in is not static but ever-changing, carrying around the same old combination of genes for generation upon generation can be detrimental. Mutations that actually confer some sort of benefit are rare (most are completely neutral), and so organisms “invented” a way to introduce some variety.

This is the beginning of sex, and eventually it led to sex as we know it - where two gametes, each carrying half a genome, fuse to form a new individual. Since you’re specifically asking about how the sexes appeared, I’m not going to go more indepth about the theories of why organisms started having sex in the first place.

In the beginning of sexual reproduction, there were (probably) no males or females. Many species still don’t have sexes as we know them - there may be some small differences (we might call one individual +, another -), or in some cases, none at all. When there are no differences, everyone can mate with everyone in a free-for-all sex bonanza. However, reproduction is tricky and expensive - it costs time and resources. The more you invest in your offspring, the better your genes will fare in the next generation - but, the more you invest in each of your offspring, the fewer offspring you can afford to produce. So it’s not surprising that while some individuals evolved a propensity for creating large, well-supplied gametes, others evolved to “cheat”, producing small gametes that could fuse with the larger ones. Essentially, maleness and femaleness evolved side by side. If there’s a lot of female-type individuals around, producing a lot of big fat well-supplied gametes, it’s very advantageous to be a “cheater”, producing many small gametes that might fertilise the big ones.

Sex organs, the pretty kind

The point is, the evolution of maleness and femaleness - as defined by gamete size and motility - is really not weird at all. It’s no more odd than considering the co-evolution of parasites and hosts, or symbiotic relationships. Remember that it all happened very gradually and not overnight. And remember that the organisms that first evolved these traits were not the kind of animals that you’re thinking of, which have a whole arsenal of secondary sexual traits that are not intrinsically male or female but simply tacked on throughout the course of evolution. Thus your comment about “individual and complex reproductive systems” is also faulty, as the original males and females were simply individuals that produced slightly different gametes.

And, for the record, this is still very true for many, many organisms. In the ocean, the easiest way to reproduce is simply letting your gametes float away in the water and hopefully meet some other gametes on the way - this is how for instance corals do it. They do not have “individual and complex reproductive systems” - some of them produce big fat eggs, some of them produce small swimming sperm. That’s it. You, on the other hand, happen to be a mammal, and since mammals have the most weird and complex secondary reproductive traits of all, you think that’s what it means to be male or female. Sorry to let you down.

(I would go into why secondary reproductive traits - including breasts, uteruses and vaginas - might look the way they do, but this is already very long, so I’ll leave it for another time.)

And to come back to the superfluity of males, there are plenty of examples of organisms where males have more or less disappeared. Either the females reproduce by parthenogenesis (or as you religious folk like to refer to it, “virgin birth”), or the males exist as very rudimentary attachments living like parasites on the female. Imagine a scrotum attached to a woman providing her eggs with sperm. How does parthenogenesis work? If the environment is stable over time and you don’t need a partner to help raise your offspring, no sexual recombination of genes is required to keep your offspring fit, and this means that wasting time and energy on finding a mate is a bad idea. Females that evolve a way to produce offspring without male aid thus produce more offspring than those who do require males, and eventually the males disappear. This is really not at all weird - after all, females have everything they need to produce offspring - large, well-fed gametes. All they need to do is put ALL of their DNA in a gamete, instead of just half. Piece of cake. Males on the other hand couldn’t create offspring on their own even if their life depended on it, as the gametes they produce quickly starve and die.

I have attached an essay on reproduction I wrote a couple of years back, which explores the incredible variety of reproductive strategies among animals. I’d recommend you read through it before replying as I hope it’ll give you some apprecation of the complexity of the subject before you slag me off for being too cursory.

I obviously haven’t attached that essay to this blog post, but I do think I’m going to post it sometime in the fairly near future. Stay tuned.

religion, creationism, atheism, big bang, evolution, reproduction