Mismatch: Why Our World No Longer Fits Our Bodies

As you may have guessed, it was this book's subtitle that caught my eye. Why Our World No Longer Fits Our Bodies. You can't get more blatant than that. Does the book live up to this audacious title? Are today's lifestyles more than our bodies can handle? I'll leave it up to the reader to draw their own conclusions, as this question is difficult to answer, but the evidence is compelling enough to suggest that changes need to be made.

The authors, Peter Gluckman and Mark Hanson, do a very thorough job of exploring the premise that the human body is mismatched to the modern urban lifestyle. The evidence is clear, argue the authors, and can be found in the increasing cases of diabetes, heart disease and obesity in the developed world. There are also more subtle consequences of our mismatch, such as those brought about by the falling age of puberty. Their solutions come right at the end of the book, and are a logical follow-on from their supporting evidence, but are perhaps are bit too brief. The aim of these solutions seems to be to raise people's awareness of the issues, rather than present final answers. Which is reasonable, given that the authors note that the application of evolutionary developmental biology to human medicine is a new field of study.

The relationship between our evolved biology and the nature of the environments in which we live is the real focus of this book. Generalist species such as humans have a broad capacity to adapt or cope over a range of environments but may not be so well-equipped to live in a particular environment as a specialist species. But it is important, the authors note, to distinguish between thriving in an environment and surviving or coping in that environment. Trade-offs which can affect our health and reproduction may have to be made once we move away from the centre of our comfort zone.

Living successfully for humans means being well-matched to the environment. The greater the shift from the environment at the centre of the comfort zone, the greater are the changes in physiology and behaviour needed to cope, until at some point significant costs appear.

When humans migrated progressively northwards from their ancestral home in the African savannah, they moved into colder climates where the average daily amount of sunlight fell. Occupying these new habitats in Europe and even further north gave advantages in terms of opportunities to hunt, and later to cultivate some simple crops and domesticate animals. But it also brought new threats. For example the low exposure to sunlight, especially in the winter months, reduced the production of vitamin D.

Vitamin D is made in the skin by the action of sunlight which converts a precursor molecule found in our diet into the active form of vitamin D. It is vital for many body processes, notably the deposition of bone during development. People who have chronically low levels of vitamin D during development suffer from rickets, and this is associated with skeletal deformity. Older adults who are vitamin D deficient are more likely to suffer brittle bone disease (osteoporosis) and even minor accidents produce fractures. This had not been a problem in Africa as sunlight levels were high throughout the year, and our ancestors had evolved to have dark skins as the melanin protected against the other harmful effects of sunlight.

In moving north we needed to have paler skins, filtering out less of the sun's rays and optimising our production of vitamin D. The cost of this strategy is that there is a higher risk of skin cancer in people with paler skins, triggered even in Europe during the summer when the sunlight exposure can still be high.

Before reading Mismatch, I had a limited understanding of evolutionary biology. So I found the authors' clear and concise introduction to its principles and processes quite useful. All the basics are covered early on, such as genes, variation, selection, adaptation, and inheritance. At the risk of veering off-track, I'll now provide a short overview of evolution for anyone who's interested.

The creation of a new species is the result of an accumulation of changes in the gene pool of an ancestral species. This usually occurs when some members of a given species become separated from the whole. This reduction of the gene pool means that over time new traits gradually become dominant, until the new group no longer resembles the old, and interbreeding between the two is not possible. This is known as macroevolution, or speciation, and takes thousands of generations. The genetic changes that occur in a population with the passage of each generation are known as microevolution. The accumulation of many microevolutionary changes leads to macroevolution.

Microevolution goes something like this: (1) Two individuals of the same species get together and mate. (2) Two sex cells or gametes (one from each parent) unite and form the first cell of a new individual, known as the zygote. (3) The zygote divides multiple times, producing identical copies of itself. Errors in this copying process result in mutation. (4) Mutation alters the genetic code of the offspring, resulting in the introduction of new traits not found in the parental generation. These traits are termed variations. (5) If a certain variation helps this new individual to better adapt to its environment, it will be more likely to survive and reproduce, thus passing on the variation to its progeny. This is known as the theory of natural selection.

In short, natural selection acts to select characteristics or traits that confer greater fitness within a given environment. It involves four straightforward principles: (1) there are more members of a species born in each generation than will survive; (2) there is variation in physical and behavioural characteristics among individuals within species; (3) this variation is heritable, and (4) characteristics that result in an individual surviving and reproducing tend to increase in frequency in the population, whereas characteristics of non-survivors decrease.

So natural selection acts on the most advantageous heritable variations. Those individuals whose characteristics best match them to their environment are said to have the most advantageous phenotype, which is defined as the observable characteristics of an organism. The phenotype is determined by both genetic and environmental influences. The genetic basis of phenotypic traits is known as the genotype of an organism. The genotype is the range of specific genes an organism possesses - in other words, the genetic constitution of an organism.

For example, my genotype for earlobes describes which version, or allele, of earlobe gene I have been gifted with. My father has free earlobes (dominant gene, which we'll call E), while my mother has attached earlobes (recessive gene, which we'll call e). Free earlobes hang below the point where they attach to the head while attached ones do not. My father's genotype for earlobes is Ee, and my mother's is ee. Since I have attached earlobes, my genotype for earlobes is also ee. If I possessed the dominant E allele, the instructions from this would have overpowered those from the recessive e allele and I would have free earlobes.

As a rule, any trait that reduces an individual's struggles in life could be considered beneficial. And anything that brings struggle into an individual's life could be considered a predator. Those individuals that have the necessary traits to overcome predators will survive long enough to reproduce. As an example, consider two different varieties of ladybird living in a lush green forest. One is coloured green, the other is orange. Green ladybirds blend in to their environment, so are much safer from hungry birds than the orange ones, who stand out like a sore thumb. Thus the green ladybirds will survive and increase their numbers, while the orange ones will slowly disappear from the species.

Without these two variations in ladybird colour, there would be no selection. The green colouring trait happens to be beneficial and over time becomes more common in successive generations of the population. The proliferation of green ladybirds means that as a whole, the species has become better adapted to its specific ecological niche, and has thus evolved.

The genotype provides the crude settings for the organism's development of its mature phenotype. But the environment also plays a large part in an organism's development. Epigenetic changes (changes that occur independently of genes) during development drive the phenotype towards a better match with its environment. The authors show that there are circumstances in which the resulting phenotype can turn out to be inappropriate, and these are mainly a consequence of modern environmental influences.

After all, humans evolved to inhabit a world very different from that which we have constructed for ourselves. It is well-known that Homo sapiens originated in the grasslands of Africa some 160,000 years ago. We lived as hunter-gatherers, relying on food from two major sources - (1) the collection of seeds, tubers, nuts, and fruits, and (2) hunting. There have been various estimates of the content of this Palaeolithic diet and it is clear that it differed significantly in a number of respects from the modern diet.

The authors explain: "The Palaeolithic diet was higher in fibre content and had a much lower glycaemic index (ability to raise blood sugar rapidly) because the foods were less refined. Wild honey would be the only source of concentrated sugars and it would have been a minor component of the diet. The diet had a very different mix of fatty acids, a higher protein content, and a much lower salt but higher potassium content. There was no milk, butter or cheese, and the meat was generally much leaner than today. Hunter-gatherers dispersed in accordance with available food suppplies. They could choose their environments, within limits. There is no fossil evidence to suggest that they suffered chronic malnutrition - quite the reverse, because the data available from skeletons suggest that they achieved modern, or close to modern, heights."

Our Palaeolithic ancestors may have had a good diet, but nothing lasts forever, and after the end of the last Ice Age the changes in climate and vegetation made hunting and foraging more difficult. A significant turning point in the history of our species was about to take place - the development of agriculture from about 11,000 years ago. Agriculture first appeared in the fertile crescent extending from the Levant to the Tigris and Euphrates (modern-day northern Syria), and with it came a progressive change in diet. Herding allowed the collection of milk as a food source and there was access to fatter meat on a more consistent basis.

This transition to agriculturalist and settlement-dweller eventually led to the development of urbanisation, complex power hierarchies, and the growth of cities, states, and empires. Some people now lived in contact with much wider networks of others than they would have had they maintained the hunter-gatherer or pastoralist way of life. Prior to the development of settlement, humans lived in social groups of less than 150 and perhaps as small as 20 to 50 people. These would have been extended family groups, and this has been an important component of our species' success.

With settlement, much larger numbers of people came into direct contact with each other. Those who lived in cities came into contact with many hundreds of people. From living in a small clan where individual roles and relationships were clearly evident and the power hierarchy simple, humans came to occupy complex networked social structures where roles were subdivided and separated and intricate power and control hierarchies emerged.

Clearly our social structures are far more complex today than they were when we evolved on the African savannah. This evolutionary discrepancy has been further magnified by a phenomenon the authors term "maturational mismatch". They observe that throughout most of our history, there was synchronous maturation of our bodies and our brains at puberty. But over the last hundred years they have diverged; while psychosocial requirements have become more demanding and full maturation appears to have been delayed, physical maturation is getting earlier.

Two centuries or more ago many teenagers could, and did, take on roles as mature adults. Junior officers in the Royal Navy during the Napoleonic Wars were in their early teens. Has today's society become so much more complex that adolescents need to know so much more to become an adult?

Gluckman and Hanson surmise that external influences like the media and the loss of tight societal pressures may have reinforced exploratory behaviour in adolescents, thereby delaying the development of attributes such as responsibility and self-control. The way adolescents are treated by society may also explain their delayed psychosocial maturity - as a society we confuse physical maturation with psychosocial maturation so we have a tendency to assume a person who is biologically mature is a full adult. These assumptions lead to rebellious adolescent behaviour.

This goes some way towards explaining maturational mismatch in relation to brain development. But it doesn't explain why the age of puberty is falling. The answer to this puzzle lies with diet and nutrition. The development of agriculture and settlement led to population growth, which brought humans into greater proximity with each other - static settlements dependent on agriculture allowed more people to live at one place. This led to fundamental changes in our nutrition. While hunter-gatherers had multiple ways to obtain food, populations dependent on a fixed location for their herd and crops became inevitably more at the mercy of climate and war. Malnutrition affects children first and their growth was reduced. When childhood nutrition is poor, puberty becomes delayed and so with changing patterns of settlement came a delay in puberty.

This allowed physical maturation to remain synchronised with the concurrent delay in pyschosocial maturation, as by this time social structures had become more complex and the skills needed to thrive in society took longer to learn. In today's society, complexity has increased still further, but this time puberty has not kept up. In fact, it has moved in the opposite direction. Gluckman and Hanson suggest that the reason for this is the health and wealth of modern life. The age of puberty is returning to where it was during our nutritionally-balanced Stone Age days, when life expectancy was short (around 35 years) and puberty in the female needed to begin between the ages of 7-8 to allow her a reproductive span of 16-18 years, enough time to support the youngest of her progeny to a fully independent existence.

The effect of nutrition on puberty differs before and after birth. While poor childhood nutrition delays puberty, poor fetal growth may lead to earlier puberty. Poor fetal growth due to deficient nutrient supplies is actually an adaptive response by the fetus. When the supply of nutrients from mother to fetus is poor, the fetus must reduce its growth rate just to survive. If the nutrient levels are too low, babies can be born premature. Their biological processes are able to sense that the environment within the womb is so threatening that it is wise to get out early in order to maximise chances of survival. Accelerated maturation and premature birth means that the individual is less likely to live a long life, so sexual maturation is also accelerated to ensure gene transmission to the next generation.

When a fetus develops in a constrained environment and then lives in a richer one after birth, there are several outcomes. Advanced sexual maturation is one - this is most dramatically observed in children who were born in very poor societies but then adopted and brought up in the richest countries. Their rapid switch from poor early nutrition to good childhood nutrition is associated with much earlier puberty - with some girls having their first period as early as 6 to 8 years of age.

A further outcome is a greater likelihood of developing obesity. Maternal constraint is a natural process in the mother that generates an upper limit on how much nutrition the fetus can sense. It may have given our species an adaptive edge during our evolution, because the predictive responses always made us expect to live in a slightly harsher environment than existed during our gestation. Thus as a species we are pre-adapted to expect worse than we may experience, and this would have given us an inbuilt safety margin. In fact, this is why the human neonate is born with a layer of high-energy fat reserves. If nutrition is compromised, these fat reserves serve the purpose of providing an energy buffer for brain growth to continue.

But as our nutritional environments have got richer, the discordance between predictions created by these constraint mechanisms and reality has become greater. Rather than being evolutionarily advantageous, these prenatal forecasts have now become disadvantageous, and are the major cause of what the authors call a "metabolic mismatch". The consequences of metabolic mismatch become manifest as heart disease and diabetes. The preference for high-calorie and high-fat foods that developed during gestation (in order to build the layer of fat) will lead to weight gain and eventually obesity in a rich environment.

This problem is particularly important among sections of the population who have inadequate education or are in lower socio-economic groups in both the developed and developing world. These people sometimes worsen their situation through inadequate education and inability or lack of opportunity to act. The range of foods they can afford often have a higher fat and carbohydrate content. This compounds their degree of mismatch. The poor are more at risk and poverty is a major contributor to chronic disease.

Further research into maternal constraint is very important, the authors argue, as it is clear that the increasing incidence of heart disease and diabetes have their origin in the mismatch that arises from the interplay between developmental plasticity and the postnatal environment. One might think that evolutionary processes would have worked to exclude such nasty fates for our species. They have not because for the most part these issues do not interfere with our reproductive fitness. These diseases until recently only appeared in middle age, well after reproduction has been completed. Evolution cannot select against traits that appear after reproduction has ceased.

Advances in medicine have allowed humans to live longer than ever before. Right up until the last century, longevity to middle age and beyond was rare. We have always known the certainty of death, but it was not within our power to delay it. We instead used religion to deny it through concepts of an afterlife. These days, we no longer tolerate the evolutionary imperative of decline and demise after reproduction. But there is a cost to living longer.

One has been the rapid rise in the occurrence of diseases of degeneration. There is a theory (the disposable soma model developed by Tom Kirkwood) stating that there is a trade-off between the lifetime investment in growth, reproductive, and repair systems. According to this theory, those individuals which anticipate a short life invest less in repair and more in early reproduction.

It then follows that women who are able to reproduce later in life are also likely to live longer. A study in Boston found that women who were able to conceive children naturally after the age of 40 had a four times greater chance of living to 100. There are several other studies showing the relationship between a late menopause and longevity and others showing the reverse, namely that early menopause is a marker for a shorter lifespan.

Experiments on mice have shown that longevity has genetic determinants: the genes involved are those associated with growth and metabolism. If a mouse predicts a threatening environment during its prenatal development, it will invest less in growth, metabolism, repair, and longevity and try to hasten its reproduction. Conversely if it predicts a benign environment, it will invest in greater longevity. Thus in mice, prenatal undernutrition leads to reduced longevity, whereas postnatal undernutrition leads to a marked prolongation of the lifespan.

There is evidence to show that these developmental trade-offs between components of the life-course strategy also exist in humans. So what can be done? The authors suggest that the route to reducing the impact of our many mismatches lies in technological, environmental, and cultural development.

One example of technological development involves modifying the epigenetic component of our evolutionary inheritance. An experiment is described in which undernourished newborn rats can be tricked into thinking that they are fatter than they really are by giving them injections of a hormone that is normally made by fat. These injections stopped the development of obesity even when the rats were fed a high-fat diet.

Other useful recommendations are given, such as social intervention programmes and further research into the causes and consequences of mismatch. The most wide-ranging and perhaps radical recommendation involves optimising the diet and body composition of all women of reproductive age.

Any reader with an interest in biologically-based approaches to human health would find this book appealing, as would science buffs who enjoy interesting facts and trivia. This is a very informative and well-written book, and health policy-makers should be made aware of the recommendations it proposes.

The Nuclear Comeback

I went to the Academy Cinema for the second time in a week on Thursday, to see the Documentary Film Festival screening of The Nuclear Comeback. The director is a New Zealander, Justin Pemberton, and at the end of the film he stood up in front of the audience for a question and answer session. Documentaries are the kind of film in which hearing from the director can add so much to the viewing experience. While the director obviously intended to focus more on the problems associated with nuclear power rather than the benefits, I found him to be pretty level-headed in the Q&A session and not excessively biased towards his cause. During the session there was a lively debate between the director and a pro-nuclear supporter. I'll mention more about it after the following brief overview of the film.

The title relates to the recent worldwide resurgence in nuclear power generation, which has happened as a direct result of climate change and global warming fears. Global warming is caused by carbon emissions, and the major benefit of nuclear power is that because no fossil fuels are burned, no carbon emissions are produced. Nuclear power also produces far more power per tonne than any other energy source, which is extremely important, given that the world's electricity consumption is expected to double in the next 25 years.

Governments are paying attention, and consequently 27 nuclear power stations are under construction, with projections for another 136 within a decade. A new group of campaigners have arisen, known as pro-nuclear environmentalists. Bruno Comby of Environmentalists For Nuclear Energy says, "We have absolutely no choice. We need to turn to nuclear energy because it is both clean, safe and abundant enough to ensure the survival of our civilisation."

Although several pro-nuclear commentators were interviewed, including a French pro-nuclear environmentalist who said that he would be happy to have nuclear waste stored underneath his house, the bulk of the film focused on the director's visits to several notorious nuclear sites around the world. These included a nuclear fuel reprocessing plant at Sellafield in Cumbria, which suffered a large, highly radioactive leak in 2005, and of course, Chernobyl.

Chernobyl was the focus of the debate I mentioned earlier between the director and a pro-nuclear supporter in the audience. This man was no ordinary audience member, however. He appeared in the film, firstly speaking to a community group about the benefits of nuclear power and then to the director about his view that New Zealanders need to be more open-minded when it comes to nuclear energy.

The man's name is Dr. Ron Smith, and during the Q&A session, he became very irate about the inconclusiveness of the film in regards to how many people actually died as a result of the meltdown. He said that the director had not even mentioned a recent World Health Organisation report which claimed that the harmful effects of the accident had been overestimated.

I had a brief read of that report. Here is a quote from it: "Given the low radiation doses received by most people exposed to the Chernobyl accident, no effects on fertility, numbers of stillbirths, adverse pregnancy outcomes or delivery complications have been demonstrated nor are there expected to be any. A modest but steady increase in reported congenital malformations in both contaminated and uncontaminated areas of Belarus appears related to improved reporting and not to radiation exposure."

The director did indeed leave room for speculation in this section of the film. One pro-nuclear commentator he spoke to said that the best sources he had access to put the number of deaths at 56. However, snippets of interviews with two other people were then inserted, one of whom said that because of Soviet cover-ups it was hard to get an accurate picture of the real number of deaths. She said numbers as low as 37 and as high as seven million have been given.

During the Q&A session, Justin mentioned these interviews in response to Ron's outburst. He continued by saying, "We've had this debate, Ron, so I don't want to get into it now." An audience member then piped up and said, "Yeah, but the audience hasn't heard it." Sadly, they didn't go into it, and that was the last we heard from Ron.

Ron Smith was interviewed on Campbell Live a little while back, and made it quite clear that he feels nuclear energy is very safe, clean, efficient etc. Providing the opposing viewpoint was the acting Energy Minister, Trevor Mallard. I thought Trevor made good sense and also got to the heart of the matter by highlighting the prohibitively high costs of building nuclear power plants. That interview can be viewed here.

As mentioned before, climate change is the driving force behind the renewed interest in nuclear power. However, it is not completely clear whether using nuclear power will actually reduce carbon dioxide emissions. A study conducted by the Institute for Applied Ecology concluded that based on the emission of global warming gases, nuclear power compares unfavourably to:

1) Conservation through efficiency improvements
2) Run-of-river hydro plants
3) Offshore wind generators
4) Onshore wind generators
5) Power plants run by gas-fired internal combustion engines
6) Power plants run by bio-fuel-powered internal combustion engines

Of the eleven ways to generate electricity that were analysed by the Institute, only four are worse than nuclear power in terms of greenhouse gas emissions. Every stage of nuclear power production, from the manufacture and eventual dismantling of nuclear plants, to the mining, processing, transport, and enrichment of uranium fuel produces emissions. Further emissions accompany the eventual processing, transport, and burial of nuclear wastes.

Even if this data is wrong and nuclear power is clean and green, not to mention safe, as Ron Smith would have us believe, there is a far more important issue that few seem to realise. And that is that many natural resources have reached their peak, and are now in decline. Not just oil, but metals, minerals, fish harvests, fresh water, fertile land. The list goes on. Our demand for all of these resources is increasing, while the supply is shrinking.

Having an abundant energy supply such as that provided by nuclear power would just bring further problems. More available energy means further industrialisation, leading to greater economic growth. This in turn leads to further increases in population and consumption. Which would also bring about more greenhouse gas emissions.

The simple truth is that the Earth has its limits, and cannot cope with humanity's over-exploitation of everything it has to offer. We will see economic contraction in the not-too-distant future. The question is whether societies will contract and simplify intelligently, or valiantly try to maintain the status quo with ambitious projects that will be ultimately unsustainable.

Studies have shown that uranium is unlikely to last any longer than 2050. There are plenty of other energy sources that will always be around. The way forward is finding out how to utilise these efficiently. Solar and wind energy are intermittent, so we need to create better electricity storage devices to ensure power can still be supplied during off-peak periods. I think New Zealand is on the right track. We know we don't have a need for nuclear power, and we know that renewable energy sources have to be tapped to mitigate our dependence on rapidly depleting fossil fuels.

If we want the future to offer hope, we have to realise that we live in a world of scarce resources. We have to work within those parameters. The era of great material abundance is over.

Crude Impact

The 2007 Documentary Film Festival is on in Auckland at the moment, so today I went to the Academy Cinema and saw Crude Impact, which explores the interconnection between human domination of the planet, and the discovery and use of oil.

First off, I want to say that this is an important film, and I think everyone should watch it. It presents the subject matter in an accessible way, without being too preachy, and made me realise the influence oil has had in shaping today's society.

It begins by linking the world's population explosion during the last century to the utilisation of oil. Thanks to oil, agricultural practices advanced and the result was mass food production. Basic evolutionary theory states that if the food supply is abundant, the population will grow.

Nowhere is this more apparent than in the United States, and as one would expect, the US seems to be the country that the sustainability message is most aimed at. The US is a huge consumer of oil when you consider its population, and this stems from the days when it produced more oil than any other country. This is what enabled the ascent to power - it was able to use oil to produce a wide range of products, which provided export income. With increased wealth came increased expectations. In the 1950s, the American dream of owning a large house, a car, and many possessions began.

The film mentioned that Americans are no more happy today than they were in 1950, yet today consumption levels are many times higher. Ever-increasing consumption levels require an ever-increasing demand for energy, yet if more possessions will not lead to more happiness, then why has this culture of excess become so ingrained?

In 1992, President George W. Bush Snr famously said "The American way of life is non-negotiable" and it was this attitude that provided the justification to strike oil deals with the Middle East. More oil had to be found to preserve the American way of life, and US supplies had long since failed to meet the demand. In 1956, Shell geologist M. King Hubbert had warned that oil production in the US would peak in the early '70s and decline steadily thereafter. He wasn't taken seriously.

But Hubbert was right. The demand for oil in the US has continued to rise, but now the vast majority of it is imported from Third World countries. One such country is Saudi Arabia, and the fact that the US willingly compromised its ideals to create a partnership with the Saudis is a good example of the power that oil exerts. Saudi Arabia is a country that is not concerned with its citizens' general well-being. The government rules in an authoritarian manner, and would seem to have very different values to those which the US espouses. Yet a deal was struck with the Saudis - the terms being that they would provide the US with oil, while the US would help them maintain their power and provide weapons when needed.

The human impact of this insatiable demand for oil was also explored in the film, with the example given of how the indigenous peoples of Ecuador had their habitat destroyed by oil drilling. Their water sources were irreversibly polluted by sub-standard drilling practices and has lead to many of the natives dying from the carcinogens. The Crude Impact website states: "As oil production increases, often the poverty level of regular citizens and indigenous peoples increases as well. These people rarely benefit from the wealth extracted from the land on which they live."

Another example of the human impact showed a prominent protestor in Nigeria being executed for trying to stop oil drilling from taking place on his people's land. African countries are often ruled by dictatorships, and the dictators will make deals with foreign countries without a thought for their fellow countrymen. The people on these lands are having their most precious asset stolen from them, and they can't do a thing about it.

Environmental issues were also raised, such as widespread species extinction due to pollution and global warming. Our continuing dependence on fossil fuels is the primary cause of global warming, and while the film did have a shot of a field of solar panels, there were not really any ideas given about how to meet our energy needs in an alternative way. The advice for now seems to be "reduce your energy demands, so that the oil that is left will last longer."

This may be easier said than done, considering the fact that the Chinese are experiencing an industrial boom. It was said in the film that if every Chinese person were to consume as much as each American, we would need six Earths. Another interesting statistic was given, and this was that if each American household replaced one of its lightbulbs with an energy-efficient bulb, the resulting reduction in energy consumption would be akin to removing one million cars from the road.

Current consumption levels cannot continue. The Earth has its limits, and to replace one energy-producing resource with another will not change this. Four recommendations were given to pave the way for sustainability: 1) Reducing the population. The film states that when women are given social, political and economic power, population stabilises and may even decrease. This is really about gender equality and giving women in less developed countries the same right to education as men. Women with more education have less children. 2) Reducing dependence on fossil fuels. 3) Buying locally produced food and other goods. This means that less transportation energy is consumed. 4) Spreading the sustainability message to the political leaders.

Our technological skill has progressed exponentially over the past century, but little attention has been paid to the long-term costs of our actions. The "bigger is better" attitude needs to be erased from the human psyche and new paradigms have to be developed. Without sustainability in the forefront of our minds, our short-term gains will do nothing more than bring long-term pain.

Ratatouille

I saw Ratatouille today and I thought it was amazing. Intelligent, funny, heart-warming, emotionally satisfying - I can't say enough good things about it. The animation is brilliant, the story has meaning, and the characters don't feel as if they've been dumbed down to target the younger audience, as seems to be the case with most of the kiddie fare produced these days. I was spellbound all the way through. This is a very likeable and well-made movie and I would have to say it is easily one of the best movies I have seen this year.

One thing I particularly appreciated was that the story felt less conventional than what I have come to expect from my cinema visits. Ratatouille's themes - such as "know yourself", "follow your dreams", "embrace new ideas" - were all presented in a non-preachy way, and this added to my overall impression of the movie as having a nice, simple charm. There wasn't any low-brow humour either, which I thought made a nice change.

The most surprising thing for me was that during one scene I found myself getting teary-eyed. This was not a sad scene, just an intensely emotional one. It seems to me that there are many things that I tend not to get emotionally involved in, so for a movie to bring about a strong reaction in me was a little out of the ordinary. It got me thinking that there are not enough intensely joyful moments in my life.

But that's another story. My final verdict of Ratatouille is: a thoroughly entertaining dose of escapism. You must go see it.

The Accident That Is Life

Charles Darwin once speculated that life on Earth arose in a "warm little pond" of organic chemicals. His hypothesis, stated in a letter to Joseph Dalton Hooker in 1871, was that this pond would needed to have contained all sorts of ammonia and phosphoric salts, lights, heat, and electricity. However, he was not able to test his theory, and so research in this field, known as abiogenesis, progressed slowly.

Then in 1924, Russian biologist Aleksandr Oparin put forward a theory of life on Earth developing within a "primeval soup", through gradual chemical evolution of carbon-based molecules. A further theory by J.B.S. Haldane asserted that ultraviolet light in Earth's primitive atmosphere caused amino acids (the building blocks of life) to concentrate in the oceans. And then in the famous Miller-Urey experiment conducted in 1953, Stanley Miller passed sparks of electricity through a glass chamber filled with water, methane, ammonia and hydrogen. This experiment was intended to re-create the conditions present on primitive Earth, right down to simulating lightning, which was thought to be an important catalyst in early chemical reactions.

Using paper chromatography, Miller was able to detect amino acids and other organic molecules that had formed in a trap connected to the apparatus. The experiment had therefore proved that organic molecules could have spontaneously formed from inorganic precursors, and it made headlines around the world. It seemed that the mystery of the origin of life had been solved. The hypothesis was that organic molecules were formed in the atmosphere after coming into contact with lightning, and were then rained into the ocean, where they combined to make proteins and nucleic acids, which are the basis of all life forms.

However, as with all experiments, objections were raised. Of particular concern was the fact that Harold Urey chose the gases that would be used, after assuming that these gases were present in early Earth's atmosphere. It was argued that by choosing gases that were very chemically active, Urey ensured that something would happen when the gases were placed together and a catalyst was applied. It was also later shown that the atmosphere on primitive Earth did not contain significant amounts of methane or ammonia. Scientists now believe that the atmosphere contained an inert mix of carbon dioxide and nitrogen.

When Miller repeated his experiment in 1983 using these gases in place of methane and ammonia, the resulting brew contained negligible levels of amino acids. Creationists seized upon the failure as evidence of the erroneousness of abiogenesis. Scientists returned to earlier theories to explain the origin of life, such as panspermia. This theory suggests that the origin of life depended heavily on chemicals delivered to Earth by comets and meteorites.

This is difficult to test however, and this is why it is preferable to assume that life originated on Earth rather than elsewhere in the universe. Still, the theory is considered possible, and it has the advantage of extending the available time frame and range of environments for life to develop. Moreover, panspermia does not conflict with the findings of the original Miller/Urey experiment, as many of the organic molecules that were detected by Stanley Miller are known to exist in outer space.

A meteorite that fell in Murchison, Australia in 1969 was shown to be rich in amino acids. Researchers studying the meteorite have identified over 90 amino acids, 19 of which are found on Earth. Since primitive Earth used to be nothing more than an enormous lump of rock, similar in composition to many of the asteroids and comets roaming the galaxy, it would make sense that amino acids were formed at the same time as the Earth, and hung around, in an inactive state. It also follows that many amino acids would have been transferred here by meteoritic infall.

Findings such as these lend credence to the idea that elements not originally present on Earth made their way here from space and were then responsible for the development of life. The early Earth was bombarded heavily by comets, and it is likely that this brought water here, along with a supply of complex organic molecules. Local evidence has also supported this. A meteorite streaked across New Zealand's sky on November 26, 1908. Two pieces of it were retrieved from a small crater at Mokoia, Taranaki. These pieces have been extensively studied, because the meteorite is one of a rare group that contains compounds of carbon and hydrogen.

Even though panspermia is a credible theory, science is continually unearthing new evidence, and recent experiments by Jeffrey Bada seem to have returned the origin of life to Earth. Bada is a chemist at Scripps Institution of Oceanography in La Jolla, California. He discovered that Miller's 1983 experiment, which used carbon dioxide and nitrogen to simulate the early atmosphere, produced chemicals called nitrites, which destroy amino acids as quickly as they form. Bada noted that the early Earth would have had significant amounts of iron and carbonate minerals, which neutralise the effects of nitrites. When Bada added these minerals to the experiment, the resulting liquid was filled with amino acids.

But other researchers are still sceptical of the claim that this finding disproves panspermia. James Ferris, a prebiotic chemist at Rensselaer Polytechnic Institute in New York, agrees that proteins can form after amino acids have been activated by lightning, but he doesn't see how the building blocks of nucleic acids would have developed. His argument seems to suggest that the first cellular organism arose from a combination of earthly amino acids and interplanetary microbes.

At any rate, experiments such as Bada's provide increasing evidence that science, given enough time, will find the answers to the mystery of the origin of life. It is natural to expect that for the time being, the answers will be in a continual state of change. This is the way science works - all "truths" are dependent on examination by others.

For me, the fact that the answer is not set in stone is what makes the contemplation of the origin of life so intriguing. In contrast, the problem with believing that an intelligent designer is responsible for starting life is that you have to maintain this belief, even when evidence comes along that may refute it.

Creationists like to believe that life is so infinitely complex and perfectly ordered that there is no way it could have all come about by chance. They argue that one need only look at the patterns inherent in the natural world to conclude that nature had a designer with intelligence and immense power.

Unfortunately, creationists usually overlook the fact that the creator of something as immensely complex as the universe would also have to have been created. If life cannot be the result of mere chance, it follows that an omnipotent supernatural intelligence would not just spring into existence. Therefore, there must be another designer - a super-designer - with so much power that designing a designer that can design everything is all in a day's work.

And then in order to have a super-designer you would need a super-super-designer. This is where the whole theory falls flat. I'm no closer to an answer about the origins of life than when I first started my philosophical musings.

There seems no reason to assume that the appearance of life on Earth was planned. Just look at atoms and their weird worlds of chaos. Electrons follow random paths and do not seem to be governed by any known rules. Creationists are well aware of this but do not find it convincing. They claim that the chance occurrence of the right combination of atoms needed to form even the simplest of living organisms is so remote that life must be the result of intelligent planning.

Creationists who make statements such as the above do not truly understand chemical evolution. The complex compounds that make life possible are not the result of a sudden combination of atoms; rather, they are the result of many intermediate steps and synthesising processes. Life started off in the most basic way possible, then succeeded in pushing forward. Life may indeed be an extraordinarily unusual occurrence, but this doesn't mean we should immediately assume conscious design. I quote the argument of W.T. Stace:

A man walking along a street is killed by a tile blown off a roof by the wind. We attribute this to the operation of blind natural laws and forces, without any special design on the part of anyone. Yet the chances against that event happening were almost infinite. The man might have been, at the moment the tile fell, a foot away from the spot on the sidewalk on which the tile fell, or two feet away, or twenty feet away, or a mile away. He might have been at a million other places on the surface of the Earth. Or the tile might have fallen at a million other moments than the moment in which it did fall. Yet in spite of the almost infinite improbability of that happening, we do not find it necessary to suppose that someone threw the tile down from the roof on purpose. We are quite satisfied to attribute the event to the operation of natural forces.

Biologists have accumulated a vast body of knowledge about the natural world, and this was achieved by looking no further than nature itself for explanations. Yet even with the quantity of information available, the origin of life is a topic in which the creationist view prevails. This is because it is one of the few areas for which science does not have a conclusive answer. However, having unanswered questions does not mean we should create a "god of the gaps".

Gods were responsible for disease until we found bacteria and viruses. Until recently, mental illness was thought to be caused by demonic possession. Now we know there are biochemical causes. It is only natural that God's sphere of influence will steadily shrink as we find out more and more about the universe in which we live.

Because there is no way to dust for the fingerprints of an intelligent designer who transcends natural processes, we have to stick with what is observable. Science can only deal with what is observable. In order for us to function as rational human beings, we must stop seeing patterns where there is only randomness and see things as they really are.

Plants Can Tell Who's Who

According to an article that I read in the New Zealand Herald last week, it seems that plants are able to tell relatives apart from strangers. The article suggested that plants are operating on a higher cognitive level than we give them credit for.

I've reprinted it below for your viewing pleasure. It is from the 19 June 2007 edition.

What will the vegans eat now? Researchers at McMaster University have found that plants get fiercely competitive when forced to share their pot with strangers of the same species, but they're accommodating when potted with their siblings. "The ability to recognise and favour kin is common in animals, but this is the first time it has been shown in plants," said Susan Dudley, associate professor of biology at McMaster University in Hamilton, Canada. "When plants share their pots, they get competitive and start growing more roots, which allows them to grab water and mineral nutrients before their neighbours get them. It appears, though, that they only do this when sharing a pot with unrelated plants; when they share a pot with family they don't increase their root growth. Though they lack cognition and memory, the study shows, plants are capable of complex social behaviours such as altruism towards relatives, says Dudley.

If I were looking for a non-biological explanation for this phenomenon, I would mention Rupert Sheldrake's theory of morphic resonance fields, which basically states that invisible energy patterns or morphic fields surround and affect all living things. Organisms that have surrounding energy fields of similar vibrations can communicate telepathically, and perhaps that is what these plants are doing.

However, a more logical explanation would be the biological concept of resource competition. According to the article, a plant grows bigger when it is potted with an unrelated member of its species. One obvious thing to look for is at what time each day the plant absorbs the most water and mineral nutrients. Siblings are likely to all operate to the same schedule, since their genetic makeup is similar. Therefore, they'll use available resources less efficiently than strangers that operate to different schedules.

An alternative explanation is the biological process known as allelopathy, where one plant harms another with specific biomolecules, in order to hinder this plant's growth and further its own. According to Wikipedia, "Although allelopathic science is a relatively new field of study, there exists convincing evidence that allelopathic interactions between plants play a crucial role in both natural and manipulated ecosystems. These interactions are undoubtedly an important factor in determining species distribution and abundance within some plant communities."

In any case, concluding that plants can "recognise" relatives and strangers seems a bit suspect. We have brains to perform this task. Plants do not. The researcher also makes the assumption that plants are capable of complex social behaviours such as altruism towards relatives. That's quite a leap to make. Looks to me like another case of anthropomorphism.

Earthlings

Just over a week ago, I saw a brutal and hard-hitting documentary called Earthlings. Narrated by Joaquin Phoenix, it critically explores how, over the course of history, humans have placed their own interests far above those of other living creatures. Consequently, the animals who share the planet with us undergo a tremendous amount of suffering in the name of human progress.

We were warned at the start of the movie that there would be some unpleasant scenes, but that if we managed to stay to the end, we would receive a bag of goodies. Well, "unpleasant scenes" was right, and somewhat of an understatement. Earthlings was filled to the brim with hidden-camera footage of animals being mistreated and tortured. The scene I found most repellent was of a goat that had been skinned alive. The expression on its face was one of pure terror.

The film was surprisingly comprehensive in its examination of the ways in which humans exploit animals. It started with animals being used as pets, then moved on to how we use animals for food, clothing, entertainment, and medical research. However, the brutal examples that were shown in all these areas were not, in my opinion, representative of society as a whole. There was a scene which had hillbilly types swearing at and beating pigs. Another scene showed dog catchers throwing a stray dog into a garbage truck and then watching as it is crushed with the rubbish. Japanese fishermen were shown slicing open dolphins. The most extreme and shocking examples were used in order to get the audience to sit up and pay attention.

A thought-provoking point was raised at one point: that if we had to kill our own meat, we would all be vegetarians. I can understand this, as I wouldn't want the blood of the free-range chicken that I eat once a week to be on my hands. However, many indigenous tribes around the world have no problem hunting for and killing their own meat. That's how they feed their families. Hunting is in their genes. It's who they are. The moral aspects of killing a living being don't come into it. It's the law of nature - survival of the fittest.

The men in these tribes who have been taught to hunt bring back the meat, and women and children partake in its consumption. In the same way, our society has organisations that specialise in supplying the meat. What I object to then is not the killing for food, but rather the way that these organisations 1) Waste resources, and 2) Cause animal suffering.

In the US, many, many fields are used to keep livestock. More than 800 million acres of US land (more than a third), and approximately 24% of the entire planet, is grazing ground for cattle. Then there's the land and water that is used to produce feed for those cattle. One acre of land can produce enough grain to feed about 25 cows for a day. That same acre could be used to produce enough grain to make 2600 loaves of bread. One hundred acres of land can only produce enough beef to feed 20 people. The same acreage can produce enough wheat to feed 240 people. The world's poor are starving due to this gross misappropriation of resources.

In stark contrast, it seems that the chicken and pork industries don't use enough land. Battery hens are kept in tiny cages for their entire lives, and pigs are crowded together in pens that prevent them from carrying out natural behaviours such as rolling in the slop and nursing their young. It has been said that chickens are the most abused animals on the planet. They are confined to sloping wire cages in dark sheds with little or no natural light. They will never see the sun, scratch the earth, or forage for food. Battery hens are routinely de-beaked; a process where chicks have their beaks cut back with a hot blade, causing instant and chronic pain. Day-old male chicks are killed in a huge grinder because they can't produce eggs and are too scrawny to be bred for meat.

I think if we want chickens to have better lives, free-range will have to become the norm. Of course, far less chickens and eggs would then be available for people to eat, and they would be more expensive. But this would be the only way to end the suffering. It would probably force many people into going without chicken and could potentially create many converts to vegetarianism. At least free-range chickens have a relatively happy life before ending up on the dinner plate.

I don't want to say much about fish, other than the fact that Earthlings tried to put the viewer off eating fish entirely by showing diseased fish. The virus that caused the disease is supposedly more lethal than AIDS. There is also the fact that most of the world's oceans are being fished to their limits.

I eat a lot of fish, and I am convinced that it has many health benefits. This is the one meat I would want to continue eating. I don't think beef is a healthy meat, due to its high levels of saturated fat. The argument about overconsumption of beef being responsible for the widespread occurrences of obesity and diabetes in the developed world was given a brief mention in the film. What needs to happen is that this information is shown unequivocally by the mass media. This would hopefully reduce the public's desire for beef. Less land would then be needed for cattle farming.

However, there are alternatives to beef. Just last week, I read an article in the New Zealand Herald that espoused the benefits of horsemeat. Guess what? Horsemeat is 50% leaner than beef, higher in protein, has 10 times more Omega 3, and gram for gram has more iron than spinach. It is also high in vitamin B12, rich in zinc, and very low in saturated fat. Gordon Ramsay is going to serve it at his restaurant in London. Animal rights activists weren't too happy when they heard the news, and dumped a truckload of horse manure outside the restaurant.

My guess is that people are more opposed to eating horses than cows because we use horses for entertainment. We ride them and race them, and they are seen as graceful creatures of beauty. The Herald article (which I should add, was reprinted from a British newspaper) agreed that pigs are intelligent, but said that horses are no more intelligent than chickens.

The intelligence argument is interesting. It is an example of anthropomorphism. Intelligence is a human characteristic and we can readily identify with animals that display this characteristic. It is human nature to put the most value on creatures with the most human characteristics. We have more sympathy for four-legged mammals than we do for sea-dwelling creatures with scales and fins. And most people would place the life of a fish above the life of a mosquito.

Our tendency to see a human life as superior to an animal life is given a name in the film: speciesism. This form of prejudice is compared with racism and sexism - the side with more power sees the other side as inferior and therefore tries to exploit this power.

Of course, speciesism is just another word for anthropocentrism, which is the view that humans are the most important beings on Earth. This way of looking at the world came from the Bible. The Bible teaches that humans are the apex of God's creation and all creation is there for the human to develop and use responsibly.

If it is not in our nature to see all lives as equal, what lives should we value? And what is it about these forms of life that makes them valuable? Some would say that all self-aware creatures should be valued. Some say that we should value animals that can express pain in a way we can relate to - if they scream and writhe, then why should we be masters of their fate? And if animals were killed painlessly, would it then be moral to eat them?

I don't have the answers to these questions, because the decisions people make are based on their values. There's no "one size fits all" way of living life. I don't eat red meat. I don't eat pork. In fact, I don't eat mammals at all. I may not be a vegetarian, but I do consider myself an intelligent eater. I know that vegetarians are said to be healthier than non-vegetarians, but in the end, the choice not to eat meat must be an individual one.