Darwin, Incest and Plant Sex

17 February, 2009

plantsexIn the heart of Berlin in the 1790’s a theologian named Spengel was hard at work investigating the sex of plants. Up until that time it was generally assumed that many plants, having both male and female parts, would fertilise themselves. Spengel spent much time examining plants and came to rather different conclusions that he published in his opus Das entdeckte Geheimnis der Natur im Bau und in der Befruchtung der Blumen. It went down like a lead balloon. No one was interested and his work languished unheeded and Spengel moved on from botany. If he was remembered at all it was by his fellow professors who would rather not talk about plant sex at all thank you very much.

Half a century later Charles Darwin was worried about incest and inbreeding. For his theory of Natural Selection to work there had to be enough variety within a population. Sex provided this variety but what if a population kept breeding within a small group? This was more than just idle curiosity for Darwin, he had married his first cousin and indeed his family and that of his wife had been interbreeding for many generations. It was well known amongst livestock breeders that closely related breeding pairs gave rise to poor offspring. Three of Darwin’s ten children died in childhood – he wondered if his close relationship to his wife had left him with weaker children. With these thoughts on his mind he did what he excelled at – doing an insane amount of experiments.

Darwin performed thousands of experiments in search for evidence for his theories. No armchair philosopher, Darwin was the epitome of the experimental scientist. He turned his attention to flowers, which he felt needed an explanation to fit with Natural Selection – why would plants have created these beautiful and complex structures unless there was a reason for them? It was known that insects sometimes carried pollen between plants but this was seen as a rare occurrence. Darwin set out to show that this was the main way in which the flowering plants reproduced and, inspired by Spengel’s work, he devised some simple experiments to demonstrate what would happen if flowers self fertilised as was thought to be the case.

He created two groups of plants. One group was forced to self fertilise. This is a rather easy thing to do – essentially a bag is placed over the flower so that the only interaction can come from the same plant – if fertilisation occurs it has to have been from the same plant. For the other group he castrated the flowers – pulling out the stamen before the plant was fully fertile and thus any fertilisation would have to come from another plant. After a few generations the results were clear. There were fewer self-fertilised plants, and those that had survived were stunted compared to the cross-fertilised crop. This had to mean that the main strategy for reproduction for those plants was cross-pollination, which meant the insects were pivotal in the process. And this gave an answer to why the plants had flowers – they were there to attract insects.

Darwin’s experiments and results (published in his book On the various contrivances by which British and foreign orchids are fertilised by insects, and on the good effects of intercrossing ) convinced the world in a way that Spengel hadn’t. Perhaps it was the snappy title, or that his experiments were more convincing than the theologians. In any case, plant sex had finally come into its own and took its place as part of the scientific knowledge of the age.


Idol Words

4 February, 2009

postmodernism1Postmodernism is often taken a little too far. One idea that springs up a lot from the university campus is that since we cannot have any concrete foundation on which to place our knowledge, all knowledge is relative and interchangable, a cultural imposition rather than anything ‘real’. Of course such people live their lives as if there is knowledge (they don’t try to walk out of third floor windows since they ‘know’ that’s a bad idea), so it can get a little annoying to hear postmodern ideas in the face of genuine inquiry. Nonetheless there is one aspect of postmodern literary criticism that I find can come in useful. This is the idea that what a text means is not necessarily what the author intended it to mean. Or rather, that a text can have more than one meaning based on what the audience brings to it. Personally I always like to find out what the author intended (to me that’s a pretty good ‘true’ meaning), but what happens when that’s not possible?

The bible has been read in many different ways. Christians looked at the Hebrew Bible and turned it into the Old Testament. It was the same words, but now they viewed it as a prophecy, a prediction of their saviour. Only someone with this idea in their head could possibly see this, but see it they did. The advent of christianity has changed many peoples view of what some ancient stories meant, but then so has the Enlightenment and the advancement of human knowledge, and not in the way that might be expected.

As an example, the first chapter of Genesis (the seven day creation) is not mythology. The second chapter story of Adam and Eve most certainly is, but when it come to finding a genre for the seven day creation it is more like that of the natural philosophers of the Ionian School. The ancient warring serpents have been toned down and removed – God is seen as acting at a distance, well beyond the anthropomorphic deity of the next chapter. This is the Hebrew equivalent of Empedocles or Thales naturalistic explanations. If any ‘message’ is to be taken from Genesis 1 it is that the world is God’s creation and that it is good. Quite a lot of time is spent on that point alone. This idea of the world being a good place stands in contrast to the Gnostics or Encratites or those Hindus who saw this world of Maya (illusion) as being an evil place. For them the world was to be denied, earthly delights were but temptations and the true world could be experienced by escaping from this world (through fasting and celibacy). The Genesis story stands starkly opposed to that idea, instead it instructs people to enjoy the fruits of your labours in this world.

A few thousand years later we discovered that Thales, Empedocles and Genesis were wrong. The world is not made up of four elements, the Earth does not float on water and the cosmos was not created in seven days. Can the message of Genesis survive this revelation? Well, not if you take it (as some do today) as the literal way that the world came into being. The author of Genesis may well have imagined that his was the best theory for the creation of the world, but would he have written the same if he had more knowledge? What would the author change if he knew of fossils, or saw a picture of the Earth from space?

The story of Jonah (a fun and somewhat odd book) has a message that can be fairly easily understood. Jonah is sent to Nineveh to warn the evil Assyrians that if they don’t repent of their wicked ways then Yahweh will destroy them. Jonah doesn’t want to risk going to Nineveh so he tries to run away, but Yahweh sends a fish to swallow him. After three days Jonah relents and promises to preach to the Assyrians. The King of the Assyrians hears Jonah and what do you know, he repents! So does the entire city! Jonah goes off in a huff since he was looking forward to these wicked people getting their comeuppance. In the hot sun he finds shade under a bush which Yahweh then destroys. Jonah gets all upset and Yahweh reprimands him for being more concerned over a bush than he was about millions of human beings. Who are we to judge that people are beyond salvation? That would be one message from this story. And yet this story pops up most with apologists arguing that someone could survive inside a fish for three days, as if that were important to the story. Does it matter whether any of the story ever happened? Could the same be said of the book of Job? Or even about the gospels of the New Testament?

We bring our own ideas and opinions to any text we read, in this the postmodernists are correct. The literalist has made an idol of the bible and will read the words as truer than reality itself. The liberal christian will seek positive meaning from tales that may well be allegorical. And the anthropologist will try to read the text as the author intended, requiring knowledge of the cultural milieu, the sitz im leben. My own bias shows now, as though I agree that the text means different things to different people, I do feel there is one meaning which is closer to ‘truth’ and here I must part with the postmodernists who might indeed have taken things a little too far.


The darkness of the soul when contemplating the cosmos

Nobody likes Dark Energy. The name itself, like Dark Matter, tells us that we don’t know what it is. It’s a placeholder name for some anomalies between theory and observation. It started in 1998 with some distant supernovae that suggested that the rate at which the universe is expanding is increasing. There is a type of supernova (Type Ia) that is used as a so called ‘standard candle’. They always give off the same amount of light and so by measuring how bright they appear to us we can tell their distance. And the further away they are, the further back in time we see them, and from this (and some snazzy mathematics) it was becoming clear that the universe wasn’t just expanding, but getting quicker and quicker at expanding. Suddenly we were living in a special time.

It’s a general assumption in physics that we don’t live in a particularly special place or at a particularly special time. Sure we happen to live on a planet that supports life, and we live after a certain time – certainly life as we know it could not exist until the first generation of stars had burned the higher elements into existence. But we could safely have lived a few billion years ago and the universe would be much the same, and we could live a few billion or trillion years into the future and everything would be essentially the same as now.

Dark Energy changes this. Now the past is receding with an alacrity that will one day hide the evidence of the Big Bang. A lot of what we know about the early universe comes from observations of the Cosmic Microwave Background radiation. But with the acceleration of the spreading of space the radiation will one day slip away and no longer be a clue that we can look at to discover our past. Less than a hundred years ago it was thought that the Milky Way Galaxy was the entire universe – a massive collection of stars surrounded by an infinite empty void. Improved telescopes have shown us that this is not the case. The 400 billion stars of our galaxy have cousins in the hundreds of billions of other galaxies we have seen. Yet in the dim and distant future when space is stretched further and further our local group of galaxies will be all that is visible to the civilisations that exist then. Not for them the discovery of receding galaxies, no clues to lead them to the idea of a singularity from which all we know has come. Indeed by then the local group of galaxies may all have merged into one super galaxy and the ideas of the early twentieth century, the island universe surrounded by infinite void, will be in exact accord with the evidence.

Unless… What if we are not living in a special time, but a special place. Every way we look the universe is the same, but what if we were in the centre of a region of space which was emptier than normal. In astronomy we look far away and look back in time, but what if it’s not that things were different back then, but that things are different ‘over there’. If the rests of the universe is denser than where we are it will restrict the expansion of the universe. Our observations say that the universe did not expand as quickly in the past, but maybe it’s just that the universe didn’t expand so quickly in denser areas. If this is the case then we will have no need of dark energy to make sense of things. Within ten years we will have telescopes capable of measuring enough of a sphere around us to test if this theory is true. Then we will know whether we live in a special place, or just in a special time.