Principles of Evolution

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 t

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

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

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 en

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

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 storag

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 su

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

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

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 ancesto

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

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 topi

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

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

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 .

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 reproduct

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

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 th

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 come

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

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

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, b