Blooming, Buzzing Confusion

White Girls Can't Sunbake

2005-01-17T01:25:00.000+10:00

It’s hot. Bloody, stinking hot. This was the phrase that reverberated persistently through my brain today, despite my serious attempts at distraction.

Having lived in Australia most of my life, very few people can understand why I would have any trouble at all with hot weather –wasn’t I born and bred in it, after all? When I went to live overseas for a few years this theory took an even further battering, for apparently not only did I despise the heat, but I revelled in the crisp, cold winters that I had never before experienced, standing outside in delight as light snowflakes fell all around me.

Observing that the “much experience with weather X leads one to like weather X” hypothesis was crumbling under the weight of the evidence, I tried to come up with a new theory. When people quizzed me about the apparent contradiction, I confidently informed them that although I was Australian, my close ancestry was from Eastern Europe, and thus, I was genetically adapted to cold weather.

Although this explanation involved completely shooting from the hip, it did seem very likely to me that there might be an evolutionary reason why people who are historically from cold climates have pale skin, and those from very hot climates have dark skin. I was very excited, therefore, to finally get the opportunity to learn about a feasible explanation for how skin colour may have evolved. Explained in Stephen Oppenheimer’s book, The Real Eve (and also in the fascinating video of the same name), there have historically been evolutionary tradeoffs to having lighter or darker skin.

Oppemheimer explained that in very sunny climates, it would have been adaptive to have dark skin, as the melanin producing skin pigmentation protects people from too much ultraviolet sunlight (and therefore from skin cancer and death), and also acts to radiate excess heat. It further acts to protect folic acid from being destroyed (particularly important during pregnancies).

Conversely, for people living in cold climates, they would have evolved very little skin pigmentation as there would have been a much decreased risk of skin cancer, but a much increased need to allow for as much sunlight as possible to filter in. This would have included the ability to absorb as much Vitamin D from sunlight as possible.

Therefore, there are different gradations of skin colour that one would expect to find (and indeed, does find) in different countries, depending on their latitude. As Oppenheimer notes: “From the available genetic evidence, Africans appear always to have been under intense selective pressures to remain dark-skinned. Outside Africa, though, we can see gradations of skin and hair colour as we move from Scandinavia in the north of Europe and Siberia in the north of Asia down to Italy and Southeast Asia in the south of those regions. (pg. 199).”

This leads to the obvious problem that dark skinned people who have in more recent generations moved to cold climates, and people with very pale skin (like yours truly!) who have moved to very hot climates, can lead to serious health risks. Oppenheimer even provides the example of European immigrants to Australia, and, noting that Aussies have the highest skin cancer rate in the world, predicts that this immigration has
“started (white Australians) on the slow evolutionary path that will eventually lead to descendents of Europeans becoming generally darker-skinned” (pg 199).

I used to like this example, because I thought that it was a nice simple illustration of how natural selection is still clearly acting on human beings. I don’t know if I agree with Oppenheimer anymore, though. Now, I’m not so sure, whether these tradeoffs would not be offset nowadays by advances in cultural evolution. Let me explain.

For there to be some sort of selective pressure on some aspect of our behaviour or phenotype to change, it would have to affect our levels of reproduction. So in the past, if someone with pale skin lived in a hot climate, they would have been more likely have greatly suffered from bad sunburns or skin cancer. They would have therefore produced fewer (if any) offspring compared to their darker-skin counterparts. Nowadays though, it is very rare for people to die of skin cancer due to effective detection and treatment, or even get the cancer before they’ve had an opportunity to reproduce. So I am not convinced that the dangers of excessive ultraviolet rays would still lead to a decrease in pale skinned people. Similarly, I’m not convinced that people with dark skin would necessarily be selected out in cold climates, if they receive the vitamin supplements they would otherwise be getting from excessive sunlight.

These are just speculations, however. Who knows, as the hole in the ozone layer increases, our battle against skin cancer (arriving sooner in people’s lives) may not be so easy to fight. Furthermore, people getting supplements they need to substitute excessive sunlight depends on wide availability of these supplements, and effective education about the need for them.

For now though, as I contemplate going to sleep, when it is still 26C (78F) and 89% humidity at 1am, at least I can feel vindicated in the knowledge that I *knew* growing up in this climate did nothing, damnit!

D & C

Meditation Changes Your Brain!

2005-01-09T13:05:00.000+10:00

An article in my local newspaper today announced the exciting news that meditation can change the way your brain is wired together. Neuroscientists measured the brain activity of people who had many years of experience with intensive meditation (Buddhist monks), and those with no meditation experience (students plucked from the researchers' university). They found that the monks had a far higher level of activity of a particular type of brain wave (gamma waves) in an area of their left frontal lobes than did the untrained students. Furthermore, the more experience a particular monk had with the meditation technique, the more activity was present.

Now, I am the first to admit to knowing nothing about meditation. Despite having a very disconcerting experience the only time I attended a few classes, I am completely agnostic about its potential effects. I would have no trouble believing that evidence could be collected (or already exists) demonstrating that it has stable positive effects. Where I am very skeptical, however, is when considering the claim that: "Experience with X can cause Y changes in the brain!". This is a claim that is made over and over again in the media about all sorts of abilities, and it is the implications of this sort of claim that I am interested in analysing in further detail here.

My problem with this type of claim is straightforward; I don't think being told how a particular phenomenon affects brain activity tells you anything new at all (of any substance) about that phenomenon. It is a totally banal claim, dressed up to seem earth-shattering. This important flaw was first brought to my attention reading Steven Pinker's The Blank Slate. This criticism is therefore not original with me, and my explanation will mainly consist of a paraphrase of Pinker's argument.

Pinker states that: "...there is no scientific question as to whether experience, learning, and practise affect the brain; they surely do if we are even vaguely on the right track. It is not surprising that people who can play the violin have different brains from those who cannot, or that masters of sign language or of Braille have different brains from people who speak and read. Your brain changes when you are introduced to a new person, when you hear a bit of gossip, when you watch the Oscars, when you polish your golf stroke - in short, whenever an experience leaves a trace in the mind....Neural plasticity is just another name for learning and development, described at a different level of analysis".

To belabour the point, imagine learning to play the piano. You need to get used to how the different octaves work, the spatial representation of where your hands are in reference to the keys, and how all those music symbols you see in the music sitting in front of you can be represented on the keyboard. Eventually though, you get to the point where you can play a piece of music fluently without needing to view music, or even consciously processing where your hands are moving. It is self-evident that something must have changed in your brain to allow this transition to take place.

Similarly, knowing that people that have intensive training in meditation have differences in their brain is not very informative. What would be far more interesting is knowing exactly how the brain goes from the untrained to the trained state, or being able to make some sort of claim about the objective value of these changes (say, whether they are somehow useful or detrimental). These sort of studies, however, do not lend themselves to answering these sorts of intriguing questions.

Finally, I wish to add an important disclaimer. I have a great deal of respect for neuroscience research, and I know that the psychology department where the meditation research was conducted is a very reputable one. I have not read the primary source for this study, and it is very possible that there are more practical implications discussed in the article than I am extracting from the newspaper story. However, it is media reporting of these sorts of stories (and thus, the conceptions of these issues by the lay public) that I am concerned with here, and why I consider citing the newspaper source sufficient for my current purposes.

No doubt many people realise that the media can often misrepresent the material that they are reporting. Without knowing where the fallacies might lie, however, can make it difficult to critically assess the validity of these reports. Even with some background in the area, reading Pinker's ideas on the topic was a real eye-opener for me. New advances in our understanding of how our brains work can give us many important insights into ourselves. Hopefully though, we can differentiate between real advances, and other hyperbolic claims.

Hello World

2004-12-31T15:50:00.000+10:00

This blog has been sitting in impatient limbo for at least a month or two now. Whenever I muse over what I might write, I think "too boring, too depressing, aren't there more than enough people in the world spouting these sorts of views? What on earth is the value of yet another blog in the world?"

I still don't have an answer to that question, and for now I'll just have to leave it at that. Right now its value to me is to try to organise my thoughts in some coherent matter, and hopefully improve my writing skills.

Knowing my hesitation regarding the commencement of this blog, one of my good friends sent me this quote from a book on writing he is reading:

"Writing is not trying to figure out everything you want to say before you put pen to paper or fingers to the keyboard. Working in this way will result in having very little to say, or worst yet, having nothing to say at all. (Ever hear of writers block?) Writing almost always works best when it springs from the discoveries you make during the writing process."

I am curious to see whether this blog will gather a life of its own, or fizzle out in the deep, dark cyber void.

D & C