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Thursday, 29 December 2011

Did out feet and hands evolve together?

In The Descent of Man, Darwin suggested that bipedalism evolved first in humans, which in turn freed the hands for other purposes, such as building tools. That seems feasible, but less than a year ago, Canadian scientists created a computer model which suggested that feet and hands might have evolved together at the same time, as there is a correlation between the proportions of finger length to toe length. The researchers used measurements from chimpanzees to work this out.
It's a fairly typical causation question: did our ancestors walk upright because they were using their hands all the time, or did they start using their hands all the time because they were walking upright? Or, as in any other correlation, did they evolve both abilities simultaneously? Over the thousands and thousands of years, it is so much easier to assume they did evolve "pretty much" together, but if we were to rewind to that period in our evolution, would one or the other ability be obvious to have come first? The study doesn't actually attempt to answer this question, as theoretically it's equally possible for a change in hands to result in a change in feet, and vice versa.

But common sense points out that it isn't possible to use hands much for tool building if they are engaged in moving. So bipedalism must have started evolving before the ability to use hands in more complex activities such as stone tool making. That is just a thought experiment, though, and until more definitive evidence is found, this subject remains debatable. What do you think?

The path our humble feet have walked...

Aren't feet the natural progression from toes (read post here)? Human feet are interesting things, not just because:

a) they are made up of 25% of all bones in the body
b) many people have a fetish for them,

but because they are the small things which have evolved to hold our entire bodies.

In a previous post about how our bodies evolved so far, there is a little paragraph about our feet compared to those of Neanderthals. It emphasizes especially how our feet's evolution was closely linked with competition with the Neanderthals, in the sense that the structure of our feet enabled our ancestors to endure more prolonged walking over increasingly long distances, as well as running for long periods of time, chasing prey until it got exhausted, rather than being the fastest.

To many it seems, myself included, that human feet are so tiny - how can they support our entire body, as well as when put under pressure, for example when running? There are certain properties that our feet have evolved to have, like supporting our weight, walking and running, healing, etc.

Feet may seem like a couple of bones here and there, and some soft tissue, all wrapped in some skin. In fact, as can be seen in the picture above, our feet are made up of hundreds of ligaments, tendons and muscles, as well as 26+ bones and even more joints. The architecture going on there is very intricate, as all those smaller pieces work together to achieve the properties which allow feet to offer all their functions.

And yet, feet aren't works of perfection. They are prone to infections due to their location, touching the ground; athlete's foot? Ingrown toenail anyone? Also, they have their fair share of "genetic disorders" such as club foot and flat foot. Asymptomatic flat feet are considered a normal human variation, as they don't cause dysfunction or pain... I should know, mine are flat.

Next post in the top2toe tab will be about a certain Darwinian debate on how our hands evolved, and whether or not that was linked to the evolution of our feet/bipedalism. Darwin suggested our ancestors started using their hands for crafting/tools as their bipedalism evolved, allowing for the hands to be free. More in the next post.

(P.S.: Oh, and about the fetish bit... neurologist Vilayanur S. Ramachandran thinks that the feet are somehow linked to genitals in our minds, because they both occupy the same area of the brain...)

Saturday, 3 December 2011

Why people say "LOL" when they're not laughing

Recently I saw a picture on Facebook which was funny. Actually, it wasn't funny as much as witty. Either way, I commented on it and wrote "lol =)". Clearly I was not actually laughing, nor was the picture funny in the actual sense of the word. So why LOL?

Understanding the real meaning behind LOL requires understanding of the real meaning behind laughter.

Laughter is an expression of positiveness and approval. More powerful than any word, laughing at something or someone is a strong opinion of an underlying aspect of the situation. It doesn't have to be funny; it can be ridiculous, witty, subtle or even cruel and mocking. In essence, the word LOL has replaced actual laughter in situations where actual laughter simply isn't provoked. Yes, some pictures on Facebook are funny, but they're not REALLY that funny, and some jokes are witty but don't make us laugh.

Sometimes, LOL is used to approve of disapproving something.

"She bought a real fur coat, then binned it because the fashion changed"

This explains the sometimes ridiculous situation where a group of friends or acquaintances laugh together, despite some or most of them not really finding anything funny. They do it out of willingness to be part of the same frame of mind or group, maybe to facilitate getting closer to someone they fancy.

Wednesday, 23 November 2011

What is the point of evolution in bacteria?

This is yet another question I was asked. The idea was that bacteria aren’t becoming complex organisms “on the way”, so what is the point?

This is like another question often asked by sceptics “If humans evolved from monkeys, how come there are no monkeys becoming humans nowadays?” The Earth is a rich place, rich with resources, rich with diversity. Humans did not evolve from monkeys, it’s not like monkeys are living in the past and we are living in the present. We all live in the present, and monkeys have spent time evolving like we have. Monkeys are adapted to their environment, and we are to ours, and bacteria are to theirs. Could you live off bananas, in a tree? Could you turn water, carbon dioxide and light into food? No. There are many different niches on Earth, each of which is inhabited by different organisms. Hot springs, dry deserts, deep oceans, high mountains and an airplane are all very different places. Why would there only be one species?? We are complex for our environment, but we are not universally adaptable to anything. We CAN live in deep oceans, but that’s not our home address.

Back to the question. The point of evolution in bacteria is to have bacteria live. If that so happens to increase their complexity due to their environment and the selection pressures present (which are due to more basic, chemical or physical factors and properties), then that’s just a side effect. Food for thought.

Is evolution in bacteria different to that in primates?

I got asked a question yesterday on Facebook on whether evolution in bacteria and primates differs. The short answer is no.

The long answer is that the process of evolution itself is so simple in a way that it really doesn’t matter what its object is, i.e. what it operates on. It’s easier to understand this if you think about atoms. The forces governing their behaviour are equal properties in different measures. Mass is mass, whether it’s zero or one hundred units. The slight differences in these properties can lead to huge noticeable differences in final products, just look around.

Natural selection isn’t something that can change depending on what it acts on, be it bacteria or primates. Natural selection is there, and any difference in products is just that. Bacteria and primates are different because of the different evolutionary paths their ancestors took, the different environments and selection pressures that led to their present day evolution.

Another question was whether increasing complexity of species was an inevitable result of evolution. I suppose this is a bit like the question “Can you return a fried egg back to a raw egg?” According to our current knowledge, the answer is no, we can’t undo the burning of an egg or piece of paper. It’s hard to imagine evolution working backwards, because it’s hard to imagine undoing evolution. The matter of fried egg can’t work its way to become a raw egg, it’s an irreversible reaction. In a sense, ancient species had the resources to evolve in certain ways, but that doesn’t mean the subsequent versions of themselves necessarily have the potential to reverse it. If anything, any further evolution that leads to a similarity to previous species would not be a reversal, but merely a continuation of the same evolutionary pathway. Strictly speaking, there is no reason why natural selection on its own couldn’t lead to future species looking more like ancient species rather than more recent past species on the same evolutionary pathway.
An example that springs to mind, although not on an interspecific level, but on an intraspecific level (that is, within one species), is one insect. This insect has switched its wings on and off repeatedly over a long period of time, depending on its environment. Would you call that backwards evolution? I wouldn’t. Evolution evolves one way, regardless of similarity between past and future species. A bit like time.

Saturday, 19 November 2011

The place of intelligence in evolution

Without maybe realising, we think about intelligence as being the ability to perform changes to one's environment. We know dolphins have relatively sophisticated communication, and we refer to them as intelligent. However, they are excellent in their given aquatic environment without trying to change it, or colonise other places (land, air, space; yes, it sounds silly).

This distinction is important because changing one's environment has an impact on the selection pressures themselves, and hence natural selection and evolution. How could inability to breathe underwater be selected against if someone has an oxygen tank to breathe out of? How could inability to find a suitable nesting spot be selected against if a bird can build its own nest? The more a natural environment is manipulated into an artificial environment by organisms, the less its evolution is left to chance, as inheritance shifts from strictly molecular level and DNA, to other levels (cognition, artificial storage and memory, learning). Essentially, natural selection acting on a genetic level (reproduction, genes passed on) interplays with artificial forms of selection which act on the other levels of inheritance.

In a sense, it is possible to use alternative methods of inheritance such as learning, to control an unlimited number of people's minds. Genetic make-up is no longer enough to guarantee certain advantageous traits in an artificial environment. Children are born without knowing a certain language. It takes only 1 Albert Einstein to spread insightful ideas to countless others, countless other who may use that knowledge to one day change the universe. The likelihood of that happening due to a certain group of people at any given point in time is a lot higher than it happening due to Einstein's imaginary children.

Directional, stabilising and disruptive natural selection

Natural selection leaves a certain gene pool’s allele make-up quite different depending on selection pressures. The results are quite easy to understand. Take a population of toads. Directional selection would happen if smaller toads avoided predators better, hence larger toads would be gobbled up more frequently. The average toad size in the following generations would shift in the DIRECTION of the smaller extreme.

Stabilising selection, on the other hand, shifts extremes towards the middle values. Say small toads have less reproductive success, and large toads are more appealing to predators. Average-sized toads will be best adapted to that situation (of course, unless they too happen to have some “issue”, in which case, bad news for the toad empire). 

Finally, perhaps the most bizarre of these is disruptive selection. It occurs as a result of extreme phenotypes (noticeable traits) being better adapted to the environment than mid-range values. Say smaller toads survive better due to weather conditions during a certain period of time, while larger toads survive better during other times, but average-sized toads have no advantage at any given time.

This stuff becomes so much more interesting when applied to humans. Where you live, which type of selection do you think is taking place?

…if any.

Friday, 18 November 2011

Variety is the spice of life II

Imagine a bacterium whose only mode of reproduction is binary fission (it splits itself into two). And then the process goes on and on. All the offspring are clones. You’d expect zero variation in their DNA, and hence in their appearance and function.

Pretty dull huh? Not only that, but this population would be doomed. With only one allele of every gene, ALL of them will either be resistant to certain antibiotics, or NONE will. So, antibiotic comes around, and there is a 50% probability the population will survive. Throw in 100 antibiotics and 10 different environmental pressures, and the population is good as dead.
Good thing for them that that’s not the case, that is, not all individual bacteria have identical DNA. How is that possible, since they reproduce by binary fission?? In fact, it is mind-opening just how many different ways they have of achieving just that: variation. Some are:

1.       Conjugation. One bacterium produces a mating bridge through which a plasmid (circular piece of DNA) can pass to another bacterium.
2.       Transformation. Bacteria can take up DNA from dead bacteria and use it as their own.
3.       Transduction. Viruses which enter bacteria may pick up some of their DNA and pass it to the next bacteria they infect.
But none of these actually explain the CAUSE of DNA variation itself. By far the biggest cause of DNA variation in bacteria is, of course, mutation. One might say mutation is the inevitable effect of the very way DNA replicates, perhaps not a mistake, as it is often perceived, but as crucial a part of the overall process as the multitude of enzymes which take part. Just because it defies our (designer?) expectations of rigid rules that are never broken, doesn’t mean it is not integrated in nature as obviously as the pairing of DNA nucleotides is.

In fact, imagine a world without mutation and variation. Can you?

Variety is the spice of life

Natural selection acts on variation between organisms. In fact, evolution itself would be impossible without variation. If you have a population where most or all individuals are not varied, then there is no way the population is going to be able to adapt over time, so potential for change doesn’t exist. Adaptation can’t arise spontaneously just because it is needed.

For example, the case of the black and white moths during a time when tree trunks were painted white is a good illustration of this principle. You start with an even variation of about 50-50 between black moths and white moths. The tree trunks get painted white, so clearly the black moths will contrast highly with the white trunks. They are visible to predators, and so most die out, don’t get a chance to reproduce, therefore don’t pass on the gene (allele) that codes for their black colour. As a result, future generations have few black individuals, and a lot more white ones (as the white moths were well camouflaged so were not that visible to predators).

The point is, what would have happened to that moth population had there been no white moths at all? It’s not far-fetched to speculate that that specific population might well have died out. But imagine this: think about our current, mostly white moth population. What if the tree trunk dye gets washed away, and the white moths now appear obvious on the trunks? Does that mean the population is bound to die off anyway at some point in the future? It becomes obvious that, despite directional natural selection (directional means favouring one extreme attribute rather than another), some variation must be maintained. Indeed, some variation is always maintained by many very different processes, from the molecular level to the ecosystems. Find out about these in the next post.

Wednesday, 9 November 2011

hmmm, and DNA

You know what, I've been getting a ridiculous amount of visitors lately, and I don't know why, cos I haven't been writing much lately. Uni is good, doing DNA stuff at the moment, and I was reading about something quite interesting.

Until relatively recently, species and their ancestry was determined mostly by things such as physical appearance and function, i.e. two species look similar, so they must be closely related. Funnily enough, after DNA technology took off and it was possible to determine how closely related species are to one another, a lot of these associations and assumptions that were wrong could be rectified. That similarly looking species may not actually have a recent common ancestor, and different looking members of the same species share most of their genetic make-up. Look for yourself.
Flying squirrels on different continents developed their flying wings in parallel with each other, and don't in fact have a relatively recent common ancestor. 

These dogs however look so different yet they are both part of the same species and likely have a very recent common ancestor i.e. great great great great grandparent.

DNA is key to determining evolution in this sense, much more so than simple physical similarity that we as humans are likely to be biased in.

Friday, 16 September 2011

The spirit of LIFE, sexual selection

OK, natural selection is the retroactive mechanism in evolution. But sexual selection is proactive, it's all the singing birds, and the stubborn determination of people to control their environment and to change the environment of other living beings. If it wasn't for sexual selection, an extra layer of life would be taken away from evolution. In fact, sexual selection changes the pool of properties of living things, be them genes or behavioural patterns, more than natural selection ever could. Natural selection is a rather rudimentary process by which the utmost unsuitable, on the fringe organisms and their genes get removed, those that have ceased to be complementary to their environment. That leaves all those others, and there are quite a lot in between. Essentially, contrary to what may appear like an obvious "designer", natural selection does not shape perfectly suited organisms to their environments. It removes the unsuited ones, but of those which remain, they present a gradient of survivability factor.

That is, they are all equally suited to survive and reproduce in their environments, but not all do. Unlike natural selection, sexual selection actively seeks the very best characteristics. The best characteristics to suit an environment, and in humans' case, the best characteristics to change the environment. The more we alter our environments, the more we diminish the role of natural selection, in favour of sexual selection. Essentially, otherwise naturally occurring selection pressures (such as disease or lack of resources) have been taken over by artificially occurring ones. Therefore, it is safe to assume that there is a negative correlation between the intensity of natural selection versus sexual selection. In a case where sexual selection hardly takes place, natural selection will appear more predominant, since it will take place relatively more often, and hence a species will be merely shaped by characteristics deemed suitable to cope with certain natural selection pressures. However, in a case where sexual selection is so active that it leads a species to progressively alter its natural environment, consequently natural selection will be less prominent in the species' evolution.

Saturday, 27 August 2011

Why do fingers and toes wrinkle in water?

Let's start our Top2Toe series not with the top, but with the toe!

It's a well-known fact that our fingers and toes wrinkle when exposed for a moderate amount of time in water. There have been myths about why this is the case, one of which being that they absorb water. While the cause has not been empirically proven, the best theory put forward in my opinion is that of Mark Changizi of 2Al labs.

He thinks that the ridges formed by wrinkling prevent slipping on surfaces by increasing friction between fingers and toes, and what they lie on. This idea makes sense because, if we think about a long-gone scenario, back when our ancestors used four limbs to commute, the hands and feet were all on the ground. The bottom of a rock pool is very slippery when you get in, but does that mean that after a while in it, you become less likely to slip? Is that due to getting used to it, or due to wrinkling of toes and (if you use them) fingers?

Speculation about this somewhat trivial topic abounds, but what about the shape of our big toe compared to other primates? Read the next post on the evolution of our feet, and how past environments have shaped them.

Monday, 1 August 2011

How culture affects perception of the world

Most of us have heard of married people with kids suddenly "coming out" as gay to their families. It seems strange and counter-intuitive that they would have invested so much of their time and energy on a relationship that would have never worked out, and that they would have brought children into that situation. But something drove them on. Of course, aside from severe legal or social action in places where homophobia is widespread, most people in the above situation would be faced with others perceiving them differently.

When the environment communicates to you that a heterosexual married life and children is the best bet, then what is it a best bet for? Presumably, the widespread fear that humans will go extinct otherwise, or that that's what nature or "God" wants us to do. And of course, if we upset either, they will come and get us.

Yet, humans are overpopulating the Earth, and there is no sign that anything will wipe us out. If anything would, surely the way to prevent it is to become an astronomer, colonise Europa (Jupiter's moon) and avoid the imminent death of planet Earth. Presumably. These are all assumptions upon which best bets are placed. And the key point is that assumptions differ by culture.

So of course when the assumption is that humans will be wiped out by gays (as impossible as it may sound), the best bet is thought to be marriage and children. This drove our imaginary gay person to keep at it with their relationship and family.

What made them come out? Either:
1. the assumptions in the environment changed, e.g. a change of attitude in people, or
2. the environment itself changed, where the assumptions are different, e.g. gay marriage legal in certain places
3. the person created their own separate environment isolated from the external one.

Due to the popularity of an old post, The evolution of the human body, I have thought of creating a series called Top2Toe in which the human body is analysed in detail, taking into consideration all things like fingers, nails, arms, eyes, hair, skin... and everything in between. So check back later and don't forget to subscribe.

Tuesday, 26 July 2011

Sexual Selection, Children and Teenagers

To find out first the 2 key things about LIFE, go here.

With that in mind, we can now look at sexual selection in children and teenagers. To find out about sexual selection, read this post first. The reason I have asked you to read the first link before reading this post is because the 2 key things about life are sustainability and propagation. That is, surviving and reproducing. When it comes to children, psychologists too often, and wrongly, emphasise the "reproducing" part of life, and omit the "surviving" part. They paint a bizarre image of people that is highly sexual (in the "people have sex way) and ignores completely the importance of whatever follows after conceiving a child. Evolutionarily speaking, the psychologists' theory that they wrongly label as "evolutionary", is anything but that. Firstly, there is the assumption that what humans try to subconsciously achieve by having children is pass on their genes, that are supposedly the best, since they conferred the parents whatever it took to survive. This has become more and more false, as the artificial environment that humans have built themselves requires less genetic adaptation, and more artificial adaptation.

For example, if you were of British origin but born and raised in Germany, those "British" genes would be of no better use in the UK if you didn't speak English. What use would you be to your ancestors, if you couldn't even speak their language? And what use is a child with your genes, if they use those genes to eventually sexually select anything they want? To the extent to which children are blank canvases, parents try to manipulate the way they turn out, and many do so without realising. But external things that themselves try to be propagated, such as information, other views, other people, etc. inevitably reach those children, and depending on the child's needs, they fight to come on top on what becomes a teenager's personality. The deeply-rooted feelings and attitudes will cause the teenager to begin their own quest for sexual selection. Being new at this, some teenagers go through stages of changing their mind and style, even radically.

But when this process ends, teenagers will not allow their parents to try to change their views, because the entitlement to a personal sense of freedom of sexual selection will be set in place. This is true of Western culture, where the "external influences" are varied and encourage people to stand up for them individualistically. Can sexual selection be taught? "You must get married and have children." Someone who says that believes doing that is the best bet for surviving future selection pressures. More in the next post.

Sunday, 24 July 2011

High end products of human sexual selection, and how they provide diversity

We might think things such as laptops and bikinis are simply the result of human intelligence, but they are not. Human intelligence enables these things to be made, but that is true for toilet rolls and portable toilets, too. The difference is that some things are made to be better than anything else, and to gain popular support. Yes, they do have nice-smelling toilet rolls with Winnie the Pooh sketched on them, but what I am talking about are big, industrial productions of artificial things which are highly selected. This can be seen in the competition for smartphone dominance between iPhone and Android for example, or in the fashion industry between all the big names.

What makes an item better than another? Its suitability to the environment and likelihood to succeed. Put simply, the same things which make some species dominate a habitat, and some individuals outperform others. And of course, the drive behind selecting which traits are thought best, is the same, Sexual Selection. Why sexual? Because these traits are merely bets, just like Apple bet that people needed what they never knew they did: such thing as an "iPad". People often select things without enough evidence they will succeed or not, and that is what sexual selection is all about. To a teenager, perhaps, a style of clothing may bring them friends or dates, but on the other hand it might make them a loser. If such things were easy to predict, selection wouldn't even be needed, and that would reduce diversity which renders a species more vulnerable to unforeseeable selection pressures of the future.

For example, if all humans were to decide that Buddhism is the best religion, and all live the same lifestyle, future selection pressures that would go against Buddhism e.g. require war with armies and guns, would be overwhelming. So as they say, people don't put all their eggs in the same basket. But we do so without realising.

The manufacturing of such diverse objects satisfies our inner drive to strive for whatever we think is best, and to be able to select it. The selection tool in this case is either building these things, or purchasing them. Someone who hates Apple will not work for them, but instead will help their competitor, Windows Phone. As the saying goes, the enemy of my enemy is my friend. The product must adapt to its environment, so the reason some have touch screens is because people use their fingers to manipulate things. The reason behind a rail application is that people travel frequently. Apps which correctly predict the most popular needs (information, entertainment, organising, etc) are the most successful, just like features which are best adapted to the environment become dominant, for example the ability to use complex language to communicate.

Also, the sheer satisfaction, or addiction, of some people when they shop for clothes is linked to being in control (perhaps as a result of losing control of some other aspect in life), and being able to make personal selection decisions. Those who don't enjoy clothes shopping may place their bets when selecting their next smartphone or laptop, furniture, holidays and so on.

Yet this drive, the sex drive, shows a significant development during the teenage years, and stems from childhood which can have an impact on the direction it leads to. The reason behind children being perceived as "innocent" is the subconscious thought that children cannot select anything innately, and that outside influence will determine their outcome. After all, if this weren't true, then why would parents impose their own selections on their children, as if they are blank canvases? Maybe they are; find out more in the next post, Sexual Selection in Children and Teenagers.

Friday, 22 July 2011


Cheating in its simplest form involves supporting something, and then letting it down. If you see yourself as a collection of attributes of all kind, be it physical, mental, spiritual or otherwise, then your friends support most of them. It is a network of selection in which more people support, or select, the same things together (what they like, what they do, etc.). If one of your friends suddenly selects something which goes against everything else, say a radical view on things, then you are likely to completely abandon them and stop calling yourself their friend. Even more, you might make them your enemy.

Imagine the same goes for relationships, but more extreme, and with the involvement of a more relevant selection tool: sex. Evolutionarily speaking, it is easy to figure out why sex has become such an important selection tool, by the use of reproduction of genes. But through the ages, as humans started artificially modifying their environment, the separation of sex and reproduction, on a behavioural level, is apparent. Humans do not have a ticker in the back of their heads "telling" them to have sex so they have children. Quite the opposite is true, where those who enjoyed sex more in the distant past inevitably passed on their genes by reproduction, therefore producing modern humans, most of whom have a strong sex drive, and big potential for physical pleasure.

This urge is a by-product of that selection, and drives people today. The ability to control actual reproduction leaves sex in its own right as a selection tool, among others such as laughter. That is why we perceive a strong selective bond between those who have sex with each other. For example, if two people have sex, then they are perceived to support all their attributes, their looks, beliefs, character, etc. Hence, it is ridiculous to suggest people with contrasting attributes would have sex; for example, good looking people with unattractive people, smart people with dumb people, etc. Of course, the reality of it is different, because different people value different attributes more than others. Some are prepared to overlook everything for wealth only.

It is no surprise, therefore, that your partner having sex, or getting along with (both of which are selection tools), a potential partner whose attributes are different to yours, is so outraging. We see ourselves as a unique mix of attributes, so being cheated on is never going to be acceptable. Still, some people overlook it, or do it themselves without showing any resentment. Some people "get over it". The way this happens is either by diluting the act of cheating, and considering it a weaker selection tool (for example, having sex doesn't mean anything more than a physical act), or by reaching the conclusion that the partner still supports you more than whoever they cheated with.

The more sexual partners someone has, the more diluted sex becomes for them. Someone who has only had one partner all their life is more likely to consider sex very important in showing selection, or support for someone, while someone who has had sex with countless meaningless people is more likely to deem it as "overrated" and not associated with supporting anyone.

Check back next time for a post on High-end products of Human artificial selection. You know, like designer shoes and iPads.

Saturday, 16 July 2011

The drives behind relationship make-ups and break-ups

Before we delve into this topic deeper, I advise you first read the post on positive and negative sexual selection. Essentially, both these types of sexual selection work together, and it must be stressed that sexual selection of whichever type is a primal drive of life, equal to the other drives typically seen as primal, such as feeding, survival, etc.

It might seem that examples of modern life sexual selection in humans, such as a mere facebook "like", or supporting Chelsea FC, are not big enough or relevant enough to be caused by a drive as essential and primal as the sex drive. But remember, this drive is of utmost importance in evolution, because it shapes humans' best bets when it comes to unforeseen selection pressures. A spirit of competition and fair-play, for example, might well play a key role if the future selection pressure involves people trusting each other to work together.

How does all of this relate to relationships between people? Relationships may be seen as alliances between people, things or ideas. So naturally, they tend to form as a result of these alliances. Of course, we can all guess which things go better together, that a couch potato is unlikely to marry a gold medallist.

Positive sexual selection is the initial drive behind selecting partners. Agreeing on similar things, doing similar things, and supporting the same attitude, or best bet for the next selection pressure. This could be a political view, a certain activism, or even the seemingly counter-intuitive "who cares" attitude. Sometimes, negative sexual selection brings people together. This can be seen in those who love each other because they hate the same things. To them it is not about focusing on promoting certain things, but about destroying others, be it religion, socialism, or a certain lifestyle.

We have many relationships in life, friends, acquaintances, family. The depth of these relationships comes from the amount of common attitudes towards things we pick to select. Acquaintances are people we have a few common things with. How about that acquaintance that you liked for decades, then found out something about them, and instantly started disliking them? That is long-distance negative sexual selection, where you decide to be against that acquaintance. When it comes to primary partners, things get complicated because you don't only have to consider that single thing that made you dislike your acquaintance. Usually, there are a lot of different things to weigh out. This is why sometimes friends are against your partner, because they have a few items of information about them that they disagree with, while you know a lot more, and find it harder to decide.

Relationships break when these small things add up to too much stuff one partner cannot longer support, be it a change in lifestyle, unforeseen events which change circumstances, or even not enough excitement. On the other hand, it may be just one thing that one partner deems too much to keep the partnership going. A perfect example is cheating. Evolutionarily speaking, it is crucial for sexual selection to work properly and not be compromised. This is why we are so fierce about, and ultimately our whole life boils down to, the things we are for, and the things we are against.

Read the next post to find out why evolutionarily speaking, cheating between partners has become so unacceptable, yet at the same time many people do forgive it. No, don't listen to the psychology blabber, it has nothing to do with babies. Not nowadays, at least, and not from the point of view of evolution.

Friday, 15 July 2011

By-products of Evolution - why not everything has a purpose

Last time we looked at how certain major adaptations such as hair loss have enabled humans to survive over the millennia in different conditions, and when faced with competition from other species. Not everything about the human body has a specific purpose, though, in the sense that we expect it to. One example of such thing is the philtrum - that little channel leading from the base of your nose to the upper lip. Recent research suggests that this development dates back millions of years, and has been inherited from fish. Apparently, when human embryos develop their face in the womb, all parts of the forehead, mouth, etc come together and fuse where the philtrum is located.

Some adaptations, on the other hand, are no longer relevant not because of their nature, but because the environmental selection pressure for which they evolved has disappeared. For example, an East Asian's typical eyelid shape evolved as a result of higher light intensities in that area of the world, yet the people born with this adaptation in other areas of the world simply don't need it. Another example is skin colour. Most physical adaptations due to local environments where separate human populations used to live for a very long time are now being mixed together because people can travel more easily around the world and settle.

There are of course, those properties which happen to be a certain way by chemical or otherwise coincidence, not evolution. For example, the colour of blood happens to be red due to the haemoglobin in red blood cells, which carry oxygen around the body. Similarly, there is no reason why we must have 10 fingers and 10 toes. We have merely used what our ancestors had, to adapt to new conditions. We have four limbs, but we walk upright. We still have 10 toes, but they've changed their shape (big toes).

Essentially, evolution is limited by whatever resources there are available. No organism can just grow wheels or another brain overnight, and that is why all organisms on Earth are so interlinked and similar. For example, the structure of the heart and brain can clearly be explained from birds to cats to humans, without any huge jumps in between, just small changes over a long period of time.

Check back next time for a different topic; we'll look at how positive and negative sexual selection work when it comes to relationships.

Friday, 1 July 2011

The evolution of the human body

In order to be able to look at ourselves in the mirror and be able to answer the question "Why do I look like this?", we must look back to our ancestry and their lifestyle, over a very long period of time. For the purpose of this analysis, let's look at the human versus the neanderthal. Recently there have been found neanderthal genes within the human gene pool, but the two species are different enough to compare, yet not too different (human versus fly would be too different).

As you can see, the construction of the human pelvis and toes is different, and the human has less hair. This results in humans being able to run easily for long distances, in the detriment of short-distance running which we are worse at. We sweat better, so we can do more long-term effort. This feat is essential to better settlements, as we can discover a larger area with potentially better resources. It might seem counterproductive to not be able to run quickly for a short period, when it comes to hunting, but humans' strategy is to chase the prey for a long time until the prey is so exhausted that it gives up. Neanderthals on the other hand are much stronger, but hairier and shorter.

As can be seen in the photo above, the human female has a relatively narrower pelvis which improves running long distances, but in turn makes childbirth more difficult. Eventually though, as a result of our scientific advancements, this isn't a problem anymore because complications may be dealt with in hospitals.

The neanderthal here is able to obtain bigger prey. However, the trade-offs of the modern humans out-competed those of neanderthals, as they are now extinct while we are successfully populating the Earth. The concept that evolution means humans "came from" monkeys is not accurate. As you can see, the neanderthal is quite similar to humans. There have lived many other different cousins of ours, each with different adaptations. Out of all of them, we came on top. The ancestors of all Homo genii might have looked a bit more like monkeys, and their ancestors even more. But the key idea is that the differences between each stage are very small, like between humans and neanderthals, while the differences between whole evolutionary branches are huge, like between humans and most other animals (dogs, fish, birds).

Back to our human here, the construction of her shoulders enables better weapon throwing, while the Neanderthal could hardly throw weapons. Humans have smaller teeth, with their canines a lot less sharp, and the wisdom teeth gradually disappearing from the species (some babies are born without the ability to grow wisdom teeth at all). We cook our food to the point where it is nice and tender, and the use of huge canines simply isn't there anymore.

So next time you look in the mirror, come to think of why you look like that. It's not the image of god. Most evolutionary adaptations have important roles, such as less hair and communication. But there are some things about us that are either outdated, or simply without a purpose, like byproducts of evolution. These things prove that there is no intelligent designer up there, and that evolution itself isn't perfect either. Check back to find out what these things are!

Thursday, 30 June 2011

Alien Life II

On a lighter note today, let's look at fictional alien life forms, and how the principles of evolution apply, as far as their physical appearance and behaviours are concerned. For those of you who have watched the films "Alien" and "Predator", you will be familiar with these characters, but if you haven't, don't worry; their pics are below. The first one to look at is the alien.

This might look odd, but in fact this is the young form of the alien. It spawns from a plant-like creature, and it has evolved to jump on people's faces, insert themselves into their digestive tract, where they grow and then escape through the chest, killing them. The only explanation for this adaptation is that at some point in the past the aliens used some other host for their development, which was similar to humans. Otherwise, they have adapted very quickly to humans' advancement into outer space. (The film is set in the distant future when humans are colonising the universe)

The aliens are filled with a very strong acid which destroys every material known to man, suggesting that the chemistry of the place these aliens evolved from was very different to that on Earth. Research so far does indeed suggest that there may be silicon-based life forms, rather than carbon-based. All life on Earth is carbon-based.

The mature alien looks like this, and in the film is a vicious fighter with two mouths.

As you can see the outer shell of the alien is very rigid, as well as the teeth, as the alien harbours its acidic blood. The inner mouth can "jump" out of the outer mouth in order to increase the distance over which the alien can attack. Although the alien is a fast learner, its strengths lie mainly in its fast reactions and strong body filled with deadly acid.

On the other hand, the Predator is an intelligent humanoid who uses advanced technology to defeat its prey. The predator's body, however shows certain features that may surprise.

One of these is the predator's dreadlocks. They don't seem to serve any particular function, so they may be purely aesthetic. Not to us humans, but to them, predators. Another weird thing is their mouth surrounded by two teeth on the outside which can move to trap a victim. Presumably, the predators were great chasers and killers a long time before their intelligence provided them with their guns and spaceships. Presumably, as predators use their fangs less and less, they will diminish and fade, just like humans' bigger sharper teeth have evolved into simple, smaller teeth, the ones we all have today. The predator's body is less resilient than the alien's, due to the aliens being more physically aggressive, while the predators use their technology more. Similarly, humans are the weakest of primates, simply because we no longer make use of strength.

That is why, perhaps, the film makers decided to make a joint film, "Aliens versus Predators" where the two species are faced with each other in battle.

This is it for now, come back for the next post on the human body and evolution, where we'll look at the human, the same way we have looked at these aliens, in more detail!

Monday, 27 June 2011

Just a little note ... be grateful for your knowledge and freedom

I've just had a chat with a friend from Sudan, currently working in Dubai, about evolution, and was so shocked to find that the copy of Dawkins' "The Greatest Show on Earth" he is reading had to me SMUGGLED into the Sudan, and that he must hide it to protect his social and literal safety.

It's so sad that something so fundamental to the human race, the freedom of information and knowledge passing around unhindered, cannot be enjoyed by all, in all lands of the world. Dubai is more secular than Sudan due to its international workers, but in Sudan the laws about infidelity are strict: death.

If in the UK we are fearlessly selling Qur'ans in our bookshops along with Bibles and Richard Dawkins, the people can make an informed, personal, independent choice. What have Sudan got to fear?

Bottom line, enjoy your freedom of information, because too often it is taken for granted, in a world where it is still taken away.

I am so grateful to be an atheist and to write about evolution freely, without fear.

Positive, Negative and Neutral Sexual Selection

Positive sexual selection is the most important and obvious type. It is positive because it involves the promotion and support of a characteristic, be it good looks or ambition, sense of humour or colour. Positive sexual selection is the driving force that results in variety of organisms, as well as the variety of what those organisms make, for example chocolate corn flakes or oats and fruit. This type of sexual selection is found in so many things, a popular example of which is teenage behaviour when teenagers feel the urge to pick things to support, be it a music genre, a sexual orientation, a fashion, a sport, or a club. Positive sexual selection is what fan clubs are made of.

Know when you see something on facebook and you MUST LIKE it? You absolutely must click like? The drive behind that urge is positive sexual selection. You like that and everyone must know. Not because you want them to like you, but because you want them to like that thing. This urge might seem superficial, but in fact it is very primal.

With positive sexual selection, comes negative sexual selection. I suppose this is easy to guess. Negative sexual selection can be exampled by hate groups, protests, and all the rants about how disgusting Marmite is. A very popular form of negative sexual selection is found in politics and religion. You're on a forum, and someone has said something you disagree with. You get a really hot unstoppable urge to argue with them; you don't even know them, but it doesn't matter because you think what they said is so unacceptable it must be challenged. Studies have shown that in fact negative sexual selection is stronger than positive sexual selection. For example, saying "STOP WAR" has more impact than saying "KEEP PEACE". This may be explained by the potential danger of not acting when faced when something threatening. That is, people see it more dangerous if the wrong party gets the vote, than beneficial if the right one does.

Neutral sexual selection is just that, neutral. Nothing good or bad will happen as a result of it. You don't care about your partner being taller or shorter than you because you don't see a benefit or downside to either. Shopping at ASDA or Sainsbury's makes no difference to you, and you don't think it makes a difference to anything else. Maybe even the parties make no difference to you, so voting is pointless.

And finally, why does Facebook not have a dislike button? As mentioned above, negative s.s. is stronger than positive s.s., so in the event of facebook adopting a dislike button, people would get more bothered about topics, posts and comments, which would spur arguments and hard feelings between members, potentially making the facebook experience worse, and leading to real life events facebook may be sued for. Imagine "Boy hangs himself after tens classmates "dislike" photo". To keep things light and... positive, facebook ensures that positive sexual selection (which people generally find enjoyable) dominates the experience, through the like button.

Check back next time for a new topic on alien life, Alien Life II, in which we're going to look at some of the evolutionary principles that sci-fi films such as Resident Evil and the Alien series have used in order to create their characters/monsters.