Science Highlights of the Week

Its a funny old thing, the world of science. It covers a vast area of knowledge and research, with new discoveries being published continuously, all across the world.

Obviously, it wouldn't be possible for any one person to keep up with all the novel discoveries. Instead they can read my list of Interesting Things and Ideas that have been in the headlines this week.

Disclaimer: Some Interesting Things and Ideas may be omitted from this list for reasons of brevity, simplicity and my lack of complete omniscience

©Wikicommons; Image Credit: Emichan

People prefer sex to story telling

Covered in Nature News here.

Researchers first thought that genetic drift could be predicted through the spread of fairy stories across cultures. The idea being that, when groups of people meet each other, they would socialise by sharing folk tales and then part. Later, when they meet again, they might marry (or, more likely, just produce some offspring) and new genetic material would be introduced into each culture.

Instead it seems that the processes for sharing cultural and genetic information are not parallel. It was found that the cultural variation was more pronounced than the genetic variation across the European cultures studied.

In short, people went for sex over conversation when it came to making new friends.

You can tell how stressed an elephant is from its poo

Researchers in Africa's Serengeti National Park have found that elephants living within the protected area of the park are less stressed than those that live in the in the less protected adjoining areas of Grumeti Game Reserve and Ikoma Open Area. The scientists found this by looking at hormone levels in the elephants' dung.

More elephants live inside the park area, even though there are no physical borders marking out the park boundaries. No male elephants were found outside of the protected park. The happiness of the elephants appears to be entwined with the levels of human activity where they are living, and they have learnt not to leave the protected areas to avoid large numbers of humans.

TV lowers your sperm count

In newly published research, The Harvard School of Public Health has announced that a man's sperm quality can be significantly lowered simply by watching 20 or more hours of TV a week.

The young men was all otherwise healthy and had considerably less impressive swimmers than their contemporaries who watched little to no telly. Men who took part in mild to vigorous physical activity for at least 15 hours every week had the healthiest sperm.

Even mild increases in physical activity (5-8 hours a week) had a generally positive impact on the fitness of the sperm.

Previous research into the effects of physical activity on sperm health had only looked into comparisons between professional athletes who dedicate their lives to sport and the average man who doesn't have the time to dedicate to achieving that level of fitness.

This new data is likely to have a significant importance for couples who are struggling to conceive, as it seems that even modest lifestyle changes will have a positive impact on their chances.

We were all cute once

Maureen O'Leary at the University in New York State, has, through incredibly extensive mapping of evolutionary trees, identified the lsat common ancestor of all placental mammals.

Through genetic analysis, our fluffy, bug-eating grandma has been identified as living at the same time as the last of the dinosaurs - approximately 100 million years ago. However, currently no fossil records have been found of placental mammals predating the KPg Extinction.

Ancestral trees based around morphological characteristics can be compared to those based upon molecular characteristics, and often these two do not overlap. Trees based around morphological traits seem to suggest that placental mammals did not begin to diversify until after the dinosaurs had become extinct.

Published in The Yorker 11th February 2013

A flaw in the scale?

The Seventeen BMI calculator taken as a screenshot by recovering anorexic Shirley Wang before the  removal of the feature from the website.

Last November, a petition was sent to the teen magazine Seventeen with over 2,700 signatures requesting the removal of the hideously flawed BMI calulator from their website. The site proclaimed a BMI of 15 to be within the healthy range for an 18 year old girl - for sense of scale, that would mean a 5'6" young lady weighing in at less than 95 pounds.

The calculator has been removed, thankfully, but the problems brought up by the feature have highlighted a lot of problems in the scale we use for defining our physiques. Putting aside the fact that the "healthy BMI range" given here appears to be be pulled out of someones nether-regions, is BMI of any use to any one whatsoever?

The original BMI measurement system has been around for 150 years and is used nowadays to sort people into categories from underweight to morbidly obese dependent on the calculation: 

• weight (in kilos)/(height (in meters) squared)

This system is renowned for being wildly inaccurate, as it fails to take into account any sort of variations in gender or athletic build. Physicians will take into account factors such as age, blood pressure and body fat percentage when accessing someone's health, yet the average person at home on the sofa will simply enter their height and weight into any one of hundreds of online calculators.

Using this calculation, short people are frequently calculated as being "thinner" than they are, whilst tall people come out as "fatter". Large-breasted women often come out several point higher than they actually would be with "average" sized breasts, even if there is not an inch of fat on the rest of their bodies.

A more accurate calculator has recently be devised by Nick Trefethen, a Professor of Numerical Analysis at Oxford University:

• 1.3 x weight / height to the power of 2.5

Whilst this is all very reassuring to those at either end of the scale, the greatest flaws with BMI are at a societal level.

As a girl, I remember weighing myself and calculating my BMI on almost a weekly basis. I wanted to compare myself to my friends who were all much taller and thinner (and generally more glamorous and elegant) than I, I wanted my BMI to match theirs, thinking it would make me just a smaller version of them. I still now feel the need to calculate my BMI every time I weigh myself, aiming for that all elusive number.

The impact that this can have on any one person (young or old, male or female) is immense. In all likelihood  the result of trying 50 different ridiculous diets in early adulthood is just going to be the gain of an extra stone or three in the following years.

So why do we still use BMI? Probably because it is neat and simple. It allows us to put ourselves into boxes of "healthy" vs "unhealthy".

Yet the human body is a hugely complicated bit of machinery and every single one of them is different. Any approach to categorizing them is going to be flawed from the start.

Instead, there are other measurements and factors that one can use to judge their health if they so wish. These are much more subjective, they don't involve any neat equations and they require us to actually trust and understand our bodies.

It really revolves around how healthy you feel. Things like generally clear skin, strong teeth and thick hair tend to be noticed by the opposite (or same) sex very quickly when it come to finding prospective partners as they are good (if general) indicators of a healthy human being.

For women, a hip to waist ration of around 0.65-0.85 (a massive range, covering many body types) is well within the healthy body structure - a recent study has seen that men see a ratio of 0.7 as ideal as this is a sign of high fertility...

As for your general health, if you can comfortably walk a mile in 15-20 minutes without getting out of breath, if you can make it up three flights of stairs without needing a time out, if you eat a few green things (vegetable green, not gummy sweet green) a day, you are probably alright.

Small changes in lifestyle can have big changes in your health, trite but true. Take the stairs, not the lift; walk, don't take the bus; put down the takeaway and cook a proper meal. These will help out your body, and also your bank balance.

Every body is different, every body as an "ideal weight" that it will gravitate towards. The most important thing to remember is that no one knows your body like you. If you think you need to change in either direction, larger or smaller, DO see a doctor first. They will give you good advice and help you to feel the way you should feel.

Yuletide Thoughts

Virgin Birth


As anyone who has ever attended a Nativity play well knows, Mary became pregnant through immaculate conception, she was the virgin mother to Jesus.

Virgin births are not an uncommon phenomenon in mythology and "creative" historical stories (religious or secular), in fact figures as varied as Mithras, Buddha and Genghis Khan were all at one point reported as being carried by a maiden girl.

Hypothetically, is it possible for a human to experience virgin birth?

For Mary (XX) to have a son (XY) would be impossible. However if Mary was in fact XY but displaying a condition called "testicular feminisation" (in which the genitals develop female due to a mutation on the X chromosome leading to a resistance to testosterone), then she would at least have the correct chromosomes to pass on. This would then require the mutation that left her appearing female to reverse to allow Jesus to pass as male.
Alternatively Mary could have eaten her brother.

Not literally of course, but if she had fused in the womb with a male twin, if would have left her a genetic mosaic, carrying both the XX chromosomes to make her appearance female, and the XY chromosomes to pass on to her offspring.

The chances of either of these scientific possibilities coming to pass and actually leading to a pregnancy are so low that such an occurrence could probably be seen as miraculous.

Christmas vs Xmas


This is more a personal bugbear of mine.

Use of "Xmas" to replace "Christmas" annoys many people. But is this a recent phenomenon, a sign of text-speak over taking the word and the commercialisation of Christmas?

No, not really. In fact the first use of "Xmas" dates back to the eleventh century where monks illuminating manuscripts would use the Greek letter _Chi_ to symbolise Christ (Χριστός).

Worried about the secularisation are not new either. In 1647, Cromwell and the Puritan government effectively banned Christmas, considering it a "a popish festival with no biblical justification". The ban in England was lifted by Charles II in 1660, though in the New England and most of America (at the time inhabited by some pretty extreme Puritans) Christmas was not legalised until 1681. Even in 1776, (the Declaration of Independence), Christmas in America was still a time of fasting and piety.

Christmas Science


Moving on to more important matters, what handy science tricks can we put to use this festive season?

With chances of a white Christmas looking slim, artificial snow to decorate your home with is becoming more popular. You can make this yourself by taking the absorbent liner out of a nappy, ripping it up and adding a little water. A can of the stuff cost the better part of a tenner, whilst nappies are 12 for £5 (yes dear readers, I just looked that up for you).

Needle droppage and general wilting is a big problem with real Christmas trees. This can be solved by either buying a reusable plastic one (eurgh) or concocting a "tree saving" growth potion for your new house plant.

All you need for this is about five litres of water, 500ml of golden syrup (a food source for the tree), 4 teaspoons of chlorine bleach (disinfectant to prevent mold, fungi, and algae from growing) and 4 teaspoons of lemon juice (to acidify the hard water which helps the plant take up water and food). Stir it all together, add a copper penny (to act as a further fungicide and acidifier) and make sure you keep your tree stand topped up, especially in warm rooms.

**NB** Do not mix the lemon juice and bleach directly together, they may produce chlorine gas, add them into the large volume of water.