A Delicious Read!

Catching Fire: How Cooking Made Us Human

By Richard Wrangham.

Profile Books Ltd.: 2009.

ISBN 978-1846682858

"cooking is the missing link....defining the human essence....I pin our humanity on cooks"

-Michael Symons, Cooking historian.

Why do we cook? Richard Wrangham gives us the answer as a gripping tale through time- from when our ancestors hopped on tree tops plucking fruit to our aisle-gliding in modern supermarkets. He traces the development of cooking food and the effect it has had on human evolution.

There are numerous theories regarding the development of the modern human, Homo sapiens, from the tree shrew. A notable event happened when one of our ancestors, the Australopethicines, turned into a meat-eater. This gave rise to the species called habilines. Then, about 1.8 million years ago, the habilines gave rise to the Homo erectus. Homo erectus shares many common features with the modern man; moving over the low foreheads, big browridges, long muscular arms and short legs of the earlier species. The reasons which gave rise to this new species are not clearly established. Wrangham proposes that taming of fire and cooking food had much to contribute to this change.

Homo erectus had smaller teeth, smaller jaws, weaker jaw muscles, a smaller gut and a swollen brain like the modern man. According to Wrangham, "humans do not eat cooked food because we have the right kind of teeth and guts; rather, we have small teeth and short guts as a result of adapting to a cooked diet". The anatomy of habilines must have changed to accommodate this new diet and become Homo erectus.

Wrangham particularly focusses on the theory of "smaller guts-bigger brains" put forth by Leslie Aiello and Peter Wheeler in 1995. The duo propose that some animals have larger brains because they have smaller guts. A large amount of energy is required by guts to process food and having smaller guts means less processing which translates to more energy being available for the brain. This explains why our brains can use almost 20% of our energy intake compared to the 13% used by primate brains.

How the process of cooking using fire came into being is not a focus of this book; as Wrangham mentions it is not easy to deduce. But once, discovered, our ancestors found out the numerous advantages to a cooked meal. The food is easier to chew, most toxins are denatured and it is easier to digest.

Evidence for Wrangham's story comes from the hunter-gatherer communities found living even now in remote parts of the world and the history pieced together from fossilized remains of our ancestors. Being a primatologist himself, he also frequently compares behaviour of primates and humans and points out the role a calorie-dense, cooked meal has played in our development. An average human consumes a much higher calorific meal than a primate of the same size and also spends less energy on digesting and assimilating it. This is just due to the fact that the food we eat is cooked. The excess energy we consume is what fuels our brain and makes us the most intelligent species on this planet.

Raw foodists are slammed by Wrangham citing various experiments and freak accident cases. In most of the examples examined by Wrangham, it becomes evident that a diet of raw food only leads to a loss of weight which is sometimes followed by a decrease in fecundity; a phenomenon evolution does not favour. He further adds that a raw food diet might work in modern human society because we get high quality food all throughout the year, a luxury which was not available to our ancestors.

Particularly interesting is the book's take on the social aspects of this shift to eating cooked food. It manages to connect the act of cooking food, which began as a simple group activity, to complex male-female interactions. Food being cooked around a common fire led to building of communities. Also, cooking food was among the first tasks which got divided amongst the sexes. Males remained the hunters, women became gatherers who returned early to their homes to cook food for the males. Sounds remarkably similar to the current social order, doesn't it? Wrangham even puts forth that the concept of marriage came into being because of this division of labour created by the act of cooking food. According to him, this overrides the sexual politics which we assume would be involved in creating a bond like marriage.

Wrangham writes in a simple but compelling language which makes it difficult to dismiss any of his claims lightly. Despite dealing with evolutionary biology and even psychology, the book is almost jargon-free. The text is peppered with accounts of various experiments which are explained in a deceptively simple way. The best aspect of the book is the fact that it can manage to engage any reader since it talks about one of the most integral part of our lives- food. Lively descriptions of various methods of cooking and the ingenuity which our ancestors employed are an excellent hook which keep this story from becoming long winded or boring.

Moving from our evolutionary past, towards the end, Wrangham gives a snapshot of the current food culture. Even though we might have developed to what we are from eating easy-to-digest, processed foods, our diet seems to be now causing disorders like obesity. He calls for taking a lesson from evolution: we should manage to be fit in order to survive and be prepared to adapt to our own changing needs and the dynamic environment.

Movie Review: "Creation"

“Creation”, the film, released in September 2008. Directed by Jon Amiel, it is based on the life of Darwin. Charles Darwin is played by Paul Bettany. It chronicles his personal and professional life and how they intersected. The focus of the film is on the struggle Darwin underwent with his wife's religious fervour, his conscience and his own unwillingness to publish a theory, which in Huxley's words would “kill God”. Darwin's daughter, who died at a young age, haunts his memories and is also frequently his voice of reason.

Darwin's expeditions and his experiments are picturised in brief flashes only. However, they do manage to be an undercurrent throughout.

On the whole, the film is a satisfactory watch for its attempt to show the human face of the the now God-like, Charles Darwin.

Is the moon an electric minefield?

The dream of setting up human colonies on the moon has another hurdle. Scientists at NASA's Lunar Science Insititute team have found out that craters on the moon may be electrically charged upto hundreds of volts! The craters were recently found to contain water frozen as ice. Now researchers at NASA's DREAM (Dynamic Response of the Environment at the Moon) project have observed that solar wind, a harsh wind blowing from the sun, across the moon's rocky surface may cause the craters to have pools of electricity too. Considering the large amount of craters the moon has, it looks like the moon is one big electric mine-field.

The researchers created computer generated simulations of the moon's surface to understand the complex environment. Solar wind, which hits the moon much like a heavy gust of wind on the earth, is composed of positively charged and negatively charged electric particles. Since the negatively charged particles are smaller than the positive ones, they rush inside the craters first. This creates an imbalance of charges between the rim and the inside of the crater, like the two ends of a battery, and leads to built up of electricity. The negatively charged solar wind particles in the crater repel and push out negatively charged moon-dust inside leading to floating dust clouds.

This electric activity of the craters can hamper further lunar research by causing short outs of sensitive equipment sent on the moon. If a manned mission goes to the moon, the areas near the craters are likely to have clusters of charged and sticky dust particles which can cause scuffing of spacesuits. The air inside the spacecrafts may also become hazardous over time due to the charged dust particles.

The DREAM team is now building more complex, 3-dimensional models for gaining a better understanding of the moon's surface. This is in preparation for the LADEE (Lunar Atmosphere and Dust Environment Explorer) mission in 2012. Looks like NASA's mission has a new set of problems to battle on the restless frontiers of the moon.

A Genetic reason for World Peace?

According to many a social scientist, we are living in the most peaceful time in the history of the world. Looking back over the past few decades, we see the Gulf wars, the wars in Iraq and Afghanistan and terrorist attacks on many major cities of the world but the fact remains that this bloodshed is much lower than the everyday violence in the lives of our ancestors. Cutting off body parts, death sentences, honour killings, all once acceptable punishments, are being increasingly condemned. The human race seems to be tending towards peace. Can we hold some genes responsible for this?

This gradual movement towards peace, which we might term as a sort of tameness, can be comparable to domestication of wild animals. Wild animals, who are violent and aggressive, domesticate into friendly and docile creatures. Man was instrumental in taming; wild wolves into dogs and wild cattle into the ones which peacefully part with their milk and plough fields. How this transformation from wild to domestic occurs remains a mystery. 

A particularly interesting experiment was carried out by a Russian geneticist named Dmitry Belyaev. He tried replicating what man had done thousands of years ago, he tried domesticating animals. For his domestication experiment, Belyaev chose the silver fox. These foxes were screened and bred for their 'tamability', or the ability of these animals to be friendly with humans. Fox pups were tested for these qualities from their first month. The pups who would let the researchers stroke and feed them were selected over the ones which tried to bite or growl. By the 10th generation, 18 per cent of the tamer foxes were observed to be 'eager to establish human contact, whimpering to attract attention and sniffing and licking experimenters like dogs'. They were designated 'domestic elite'. In the 30th-35th generation today, about 70-80 per cent of these foxes are 'domestic elites'. Some are even up for adoption as pets.

Apart from their behaviour, many physical changes were observed in these foxes. There was loss of colour in certain parts of the body, some had developed a star-shaped mark on the forehead. Other changes included features which we see commonly in dogs like curled tails and floppy ears. The level of corticosteroids, responsible for the fear or fight/flight response was considerably lower in the domesticated foxes. These phenomena are common to most domestic animals.
This rapid change in physical characters which makes these foxes distinct from their forefathers seems to go against Darwin's notion that speciation or the formation a new species takes thousands of years. The mystery begins to thicken.

Scientists have considered multiple causes for these rapid physical changes. Expression of particular recessive genes conferring these 'domestic' characters was the first guess. But, during Belyaev's experiment, great care was taken to avoid excessive inbreeding which could result in any recessive gene showing its effect. Another reason is thought to be polygenes i.e. a complex system of genes which codes for these traits might be responsible for the changes. However, polygenes are very delicately balanced systems. Even a slight change in one of the component genes could lead to detrimental effects on other vital processes of the animal; this does not seem to be the case in domesticated animals. The most fascinating explanation might be that of heterochrony. Heterochrony is the hastening or delay of the events which occur during development.

Development of an organism occurs after the fusion of two cells - the ovum and the sperm, to form a zygote. This zygote undergoes multiple divisions to give rise to the multicellular structure viz. the organism, through a regulated and time-bound process. Many different transient structures are formed during development, which later give rise to various organ systems. A rather interesting one is the neural crest. Neural crest cells originate from early neural tissue and migrate across the embryo.

Dr. Mariana Delfino, from Universidad Pablo de Olavide, Seville, Spain, elaborates, "[the neural crest cells] gradually delaminate and they begin to migrate throughout the body using stereotyped pathways in order to reach specific locations where they can differentiate to new tissues." These cells give rise to various organs in body. "Neural crest cells begin as a multi-potent cell population which gradually differentiate into very specific cell types."

The different tissues neural crest cells are responsible for like the skin colour, cartilage, adrenal glands are some of those which are affected during domestication. Domestic animals show decreased skin pigmentation or spots. Ear cartilage which makes the ears stand erect is reduced in domestic animals making their ears floppy. Low levels of adrenaline (released by the adrenal gland), the hormone responsible for the flight or fight reaction, makes domestic animals less aggressive.

Dr. Delfino mentions that, "Deficiencies in neural crest migration as a result of mutations in relevant genes can have widespread effects in embryonic development as cells do not reach their appropriate positions or do so at inappropriate time points". Can such discrepancies in the timings of neural crest cell migration be causing all the changes from wild to domestic? Timing seems to be the key. Mutations in the genes responsible for this 'time-keeping' are possible targets for further study of domestication.

The experiment started by Belyaev in 1950s still continues. Using ever evolving scientific gadgets and techniques, the mystery of domestication is being attempted to be solved. As in the 'domesticated' foxes, lower levels of adrenaline than the past generations might be cause of dulling instinct to fight. If the same happens in humans and this 'human domestication' continues, our quest for 'world peace' might not be just a fantasy.

P.S. I wrote this in 2010 inspired by some writing by Steven Pinker and some other cursory desk research. Since then, Steven Pinker has written, what I assume must be an interesting book titled "The Better Angels of Our Nature" dealing with a similar topic of mankind becoming less violent. 
An article about the current status of Belyaev's 54-year long experiment was published in 2012 in Slate.   

A review: "How to dunk a doughnut"

Book review

Think before you dunk

"How to dunk a doughnut - The Science of everyday life" - Len Fisher

"Science is all around us" and Len Fisher starts his book from the scientific research he was awarded the IgNobel for. The awards which parody the Nobels. The Ig Nobels (or awards for Improbable research) are given for achievements in science that 'first make people laugh, then think'.1 The topics covered in this book seem like contenders for the Ig Nobel, humorous at first and then making you wonder.

Len Fisher won his Ig Nobel award for 'calculating the optimal way to dunk a biscuit'.2 If you have wondered what causes the shearing force which rips the dunked biscuit apart, sending it drowning down to the bottom of the mug, then this book has the answers. And yes, dunking a biscuit horizontally reduces the chances of it turning into bottom-dwelling mush.

The target audience for this book can be any curious laymen wanting a dose of science in situations he/she can relate to. As the introduction to the book begins, "Scientists, like hangmen are socially disadvantaged by their trade". This divide between the scientist and the interested laymen has been bridged in by Fisher. The book tries to give a view of the everyday world from a scientist's eyes. It manages to convey how a scientist can apply scientific method to the most common occurrences and deduce basic principles governing nature.

Following the pattern of the biscuit-dunking calculation, the book dissects many other mundane phenomena. How to boil an egg so that the yolk and the white are perfectly set and how to add up the the ever so long supermarket bill before the cashier does are some of the every day issues which have the been scientifically answered in this book. Best practices while using tools and even for sex are discussed from a purely physics-based perspective.

Anecdotes from ancient to modern times make the book a interesting read. An example is how principle of heat convection was discovered when Count Rumford burned his tongue on a seemingly cold apple-pie. I found the chapter on how to boil an egg particularly interesting as it also discusses the science of gastronomy. Scientists are trying to deduce which chemicals cause the food to taste and smell like it does and artificially produce the same to make food seem fresher and tastier than ever. Illustrating such examples makes the book appealing.

The book tries to keep the scientific answers enjoyable, however, in some chapters, the explanations are meandering and can leave the reader unmotivated to reach the end of the discourse. In the chapter about bath and beer foam, much of the topics and jargon used are priority of people having more than a basic knowledge of science.

Despite the tediousness of a few passages, the book is immensely enjoyable. It draws you into the world of science where the seemingly ordinary has complex reasons for being. The journey from indifference to wonder is worth the cost of this paperback.

References:

1. http://improbable.com/ (accessed on 04/03/2010)

2. http://improbable.com/ig/ig-pastwinners.html#ig1999 (accessed on 04/03/2010)

Your body or mine?

Would it hurt you if someone poked a finger into your friend's eye? Well, according to the scientists at the Karolinska Institute in Sweden, if you were perceiving your friend's body to be your own, it would hurt! Body-swap, an ageless folk-lore is actually a scientific possibility.

After elaborate experiments conducted by the Swedish researchers, they could prove that by altering visual and tactile sensations, an individual can be tricked into feeling someone else's body as his/her own. The participants in this experiment were made to wear a set of head-mounted displays (HMDs) which were connected to cameras placed in either the place of eyes in a simple shop mannequins (all males) or atop a big rectangular box. This means that the field of vision of the participant was now the view of the cameras.

A series of tests were done using this set-up. In one experiment, the mannequin was threatened with a knife. The participant's body reacted as if the attack was on him. This clearly establishes that a kind of belonging was developed between the participant and the mannequin body. The participants perceived it to be their own. This sense of ownership was not affected by gender, considering that all the mannequins were male, but the rectangular box did not generate any of these feelings of ownership by the participant. The most exciting aspect of this experiment was when the researchers substituted the mannequins with real human beings. The participants were put face to face with other volunteers and their HMDs displayed a field of vision of the person in front of them. So, when these two individuals shook hands, they perceived that they were shaking a hand which was actually their own. Some participants later told each other that, "Your arm felt like it was my arm, and I was behind it". Twisted logic, eh?

The researchers conclude that the perception of presence of our own body is a continuous process. The body keeps signalling our brain about its position in the surroundings via sensory stimuli, physical movements and feeling of pain. All these might also be affected by past experiences as in the case of phantom limbs where victims of amputations of limbs are known to feel pain and other stimuli where the limb previously was.

The technique of evoking the feeling of being in another body is clinically important. It can be used to treat psychological disorders like poor body image. Research has shown that 8 out of 10 women are dissatisfied with their body image. In some cases, it can aggravate to depression, eating disorders and other related psychological conditions. The body-swap technique can be used to make the patient aware of the difference between the actual physical being and perception of it by us and would help cure these disorders. Another psychological disorder which can be treated using the body-swap illusion is identity crisis. Perceiving self through another individual might help in the treatment.

However, the gaming industry is the one which is likely to exploit this 'body-swap' illusion the most. Most modern games give the player of being in a different environment and using these body-swap techniques, the gaming experience could be more and more realistic. Beware, those game-loving boys you know, might be getting more addicted in the future. It also would be more enjoyable to have a go at being some power hungry dictator or a fearless warrior yourself in these body-swap games.

Philosophers, psychologists and now neuroscientists are pondering on the nature of perception of self. More research in this field will likely help us understand how the brain can differentiate between ourselves and others; and why we know who the person in the mirror is.

Finding domestic routes

I am listening to a lot of radio programmes as a part of my curriculum (M.Sc. Science communication). Here's something that I came across: Domestication of animals is linked to neural crest cell migration during development! (Neural crest cells are a group of cells which are formed during early development of the embryo. These cells actually travel through the length of the embryo and form different organs in different areas of the body. eg: neural connections in the gut, parts of bones, adrenal gland ).
This made me think about the paper we had once discussed in Arunan sir's class ( during my other M.Sc. in Life Sciences and Neurobiology) about hierarchy and how it affects the colouring pattern in fish. Some species of fish develop different colourations depending upon their position in the hierarchy in a pond.
Can these two cases be following similar pathways? But the argument is that the colouring patterns in the fish appear after birth and due to effects of competition and stress. So, are the factors which contribute to these changes in the fish linked to any of the organs formed by neural crest cells? In the case of the experiment on domestication of foxes (which incidentally have evolved over a period of thousands of years as dogs), it was found that the adrenal gland (a neural crest cell derivative) reduced in size and function on domestication. As did other neural crest cell derived features like ears which are more pointed (floppy in dogs), tails which are straighter (curved in dogs) etc.
The implications of something similar happening in humans was also discussed in the programme. We are becoming gentler and more tolerant over the years.[which explains globalization and the fact that we can live in different countries without being frowned upon (sometimes yes) or killed as food by the natives].

I am intrigued. Thinking about it now.


http://scienceblogs.com/clock/2008/08/domestication_its_a_matter_of.php

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2493746/

Couldn't find the fish paper which we had referred to in class, this is something similiar though:
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T2J-4KDV0J8-1&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1121489900&_rerunOrigin=scholar.google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=bc1e2377ab063aea49bb59022c981525

This is the radio programme is was listening to (check out the "New normal" episode): http://www.wnyc.org/shows/radiolab/