Tuesday, February 16, 2010

Stuck on You

I've just come back from a marine zoology camp, where I've spent a week working on a group project about competition between two species of limpet. This didn't mean we were racing the limpets. We were looking at competition for a common food source - in this case, delicious microscopic algae that grows on rocks.

Below is a picture of a boulder covered in limpets. You can see why I didn't end up taking many photos on camp.

Our project involved lifting limpets off the rocks with a bread knife and relocating them to produce areas of higher than natural population densities. Then we waited to see if they would exhibit a behavioural response to being in a high density area. Having a shell is a bit like wearing a burqa - it makes it difficult for others to read one's non verbal cues - but I'm sure that the limpets' little faces were contorted with effort as some of them practically galloped away from the higher density areas at speeds of more than 4 cm per hour.

You can think of the intertidal rock pools as being like a great savannah full of grazing beasts. The herbivorous limpets are the gazelles and antelope. The predatory whelks, who drill through the limpets' shells and suck their flesh out, are like the big cats. Check out this vicious killer, Dicathais orbita:

And this glorious creature would be the elephant:

Elephant Snails (Scutus antipodes) are the giants of the intertidal rock pools. Their distinctively shaped shell is usually hidden under thin flaps of skin. When they feel threatened, the skin retracts and the shell is revealed. Having so much juicy flesh can be a liability, so these snails are typically found under ledges at the edge of pools. They come out to graze at night, when there are fewer predators around.

This Elephant Snail was part of a group which we were responsible for relocating at the end of the camp. They had been used in another group's project, in which they were tested for their responses to both a native and an invasive predatory starfish. It was a bit like the witness relocation program. Maybe, in time, these Elephant Snails will be able to come to terms with horrors they witnessed in our laboratory tanks.

Monday, February 1, 2010

Viral media

When I told my Grandma I was going on a camp to study bats, she listened politely for a few moments, then said "Yes, but really, what's the point of bats?". This was a new addition to her repertoire, which usually goes along the lines of: "I don't know why they bother having crocodiles. They're ugly, they eat people...why don't they just shoot them?" Grandma grew up in England, where over a millenia or so, people have done exactly that to their larger wild animals. The English have also replaced most of their wilderness with gardens and fields. In Grandma's opinion, this looks 'much prettier,' and is a great improvement on our ugly Australian bush.

I found it difficult to come up with an impromptu justification of the existence of bats. I didn't have the option of claiming that bats are God's creatures. After discussing mortality with her doctor, Grandma has decided that she's an agnostic. I ended up resorting to the slightly feeble argument that a) bats are cute, and b) they eat insects, which is a good thing if you hate insects. I was betting this argument on the fact that Grandma would hate insects, which, after all, are ugly and eat people. But she claimed to liked them. I'll have to remember this fact for possible point scoring the next time we have a sophisticated discussion about ecology.

I suppose I've always assumed that living organisms have an intrinsic value, not to mention their ecological significance. Even bacteria have their virtues. What they lack in personality, they make up for in useful nutrient recycling activities, or helpful gut-flora action.

However, I feel tempted to draw the line at viruses. These are entities - they can't even be called living things - that don't even bother to have their own cells. They lie around as inert capsules of DNA or RNA, only springing into action when they infect a cellular organism and hijack its cellular machinery to produce more virus genes. These genes get packaged in a protein coat and released into the world as more dormant viruses, which wait around to infect the next organism. A virus is the ultimate example of someone who needs to get a life of their own. Even parasites stoop to excreting and reproducing for themselves.

Maybe Richard Dawkins would understand the simple needs of the virus. The title of Dawkins' book The Selfish Gene refers not so much to the genetically determined selfish behaviour of organisms, but to the selfishness of the gene itself. This is because all the gene wants to do (not consciously, of course) is to produce more copies of itself. According to Dawkins, the carrier is merely the vessel of the gene. Evolution, and the variety of differently shaped bodies it has produced, represents increasingly sophisticated attempts by genes to package themselves in order to ensure their reproduction.

Judged on these terms, viruses are nature's car poolers, house sitters and refusers of plastic bags. They say no to unnecessary packaging. They don't waste valuable resources growing their own cells when there are plenty of other people's cells to go around.

But, as with a sanctimonious hippy, I just can't warm to them. When it comes to genes, I prefer the ones that have as much ornate gift wrapping as possible. The more colours and accessories the better.

Call me a sucker for a cheap gimmick, but these genes glow in the dark!

It's not just a visual aesthetic that counts against viruses. There's also a lack of narrative drama. Sure, swine flu got a lot of media coverage, but how did this make the virus feel? What does a pathogen really get out of life when it's incapable of conscious thought, unconscious thought, movement, sensory perception, feeding and mating? What is the point of viruses?

The elephant in the room, of course, is that viruses make a mockery of our limbs, brains, emotions, genitalia and rational thoughts. If we're just doing in a more elaborate way exactly the same thing they're doing with a few sticks of non-sentient genetic material and a protein coat, - that is, replicating our DNA ad infinitun - then we have to ask the question: what is the point of us? Which, in my books, is all the more reason to despise them. Essentially, I'm saying that I hate viruses because they are irreconcilably different to us, yet at the same time remind us of ourselves. Because this means I have to identify with something I hate, I only hate them more. Of course, Fascism is not always a good thing, but let's just say there's a time and a place.