As a scientist I know that correlation does not imply causation. Just because two things, A and B, are correlated does not imply that A causes B or vice versa. For example, there is a correlation between the number of pirates on the world’s oceans, and global temperature, but this does not imply that pirates, or their absence, is causing global warming. But even if there is cause and effect going on, then you still have to work out if A causes B, or if B causes A.
Genes get a good press. The DNA double helix is a iconic, and we are all know that genes are how we inherit our mother’s blue eyes or our father’s curly hair. Proteins also have a good press. Food is sold as being “high in protein” — we know we need protein as part of a balanced diet. But the third key biological polymer, RNA, gets much less publicity. This is a shame, as our cells have a lots of it (more than DNA), and it is essential to all life on Earth.
This is an update on last week’s post on a paper on cancer by Tomasetti and Vogelstein. Fur has flown over this paper, in particular with some of the media coverage. There was an interesting, and angry, article in The Guardian, and remarkably an arm of the World Health Organisation (WHO) produced a press release on the paper. They were not impressed. And journalists reflected on their coverage of the article. It was all go.
As a society we have become very dependent on antibiotics since penicillin was introduced 70 years ago. Before then healthy adults would die of sceptic shock from massive infection. We don’t want to go back to those days, and so we need to develop new antibiotics at least as fast as the bacteria in hospitals are evolving resistance to our existing ones*.
This is the message of a paper by Tomasetti and Vogelstein, that came out last week. Unlike a lot of papers in Science it is beautifully written, with a simple idea and a clear message. They start with the simple observation that some cancers are much much more common than others. For example, the American figures they quote give a lifetime risk of cancer of the colon of 5%, and risk of bone cancer of the pelvis of 0.0003%. Why the difference?
Although the average number of times people cite my papers is lower than that for a Siamese cat, people do cite my work. And so Google Scholar reckons that at the time of writing my papers have attracted a total of N = 2858 citations and I have a h-index of 27. The value h of the h-index (named after Jorge Hirsch) is the number of papers that have been cited, i.e., referenced, at least h times. I have published 27 papers which have all been cited at least 27 times.
Over Christmas, as is traditional, I have been eating and drinking a lot. The drinks include beer, wine, dessert wine, liqueurs, etc, but no ouzo, pastis or sambuca. Ouzo, pastis and sambuca all have the distinctive flavour of aniseeed. While Googling something for a paper I am drafting I came across the explanation for why these drinks become cloudy when you add water. Ouzo for example is quite strong, about 40%, and so it is often diluted with water, but as soon as the water is added, the ouzo goes from clear to cloudy.
Pretty much everywhere on Earth where there is liquid water there is life. The biochemistry that powers our cells only runs in liquid water. In the Universe liquids are rare, like Little Red Riding Hood liquids are very particular, requiring conditions that are neither too hot nor too cold. Much of the Universe is near 0 K (-273 C), which is way too cold, or inside in stars at thousands of degrees, which is way too hot. Saturn’s moon Titan is at a refreshing – 180 C, which is too cold for liquid water, but methane is liquid at this temperature. The image to the left is of the surface of Titan and the dark regions are huge lakes of liquid methane and ethane.
The plot to the left shows the distribution of heights of American women, ages 20 to 29, according to the 2007/2008 census. Data here. I couldn’t find data on UK heights, but it should be similar. Data for the heights of men are similar but shifted up a bit. The circles are the data and the line is fit of a Gaussian function to this data. The most probable heights are around 165 to 170 cm (5 ft 4 in to 5 ft 6 in). The width (standard deviation) of the Gaussian fit is 7 cm.
All organisms, from us to bacteria, need to adapt to survive. As I start to write this post, I have just had lunch and so I guess my blood sugar is probably peaking nicely. Some of this sugar will need to stored for later consumption, and doing this will involve flipping switches in my biochemistry to go from my pre-lunch state of burning food reserves to storing excess calories from my lunch.