Monday 25 February 2013

Evolution II: Survival of the fittest.

This mini-series of blog posts is going to outline the truth about the theory of evolution, and why we often struggle with the concept. These articles are intended to be read with an open, unbiased mind. If you are approaching it with your mind already made up, then the reading of it will be redundant.

'I won't ever tell you what to think; I will only give you the evidence and let you decide for yourself.' - Celia

Part Two:

Previously I discussed reasons why we believe what our parents tell us to be true; in this segment we'll begin to examine the constant struggle for survival, and how tiny changes over time can result in speciation (the evolution of a new species).

Speciation might sound complex, and it is, but once explained it should be quite simple to grasp. We all know that animals inherit traits from their parents; physically, emotionally, and intellectually. You might have inherited your mother's looks and your father's personality, or a mixture of both. You can also inherit attributes from your grandparents and great-grandparents, but did you know that each human being has around 100 new mutations? These 100 mutant points of DNA are entirely unique to you. You didn't get them from either of your parents, and it's almost impossible that your brothers or sisters will have the same mutations.

Now don't freak out, these mutations are most often neutral. It might be simply that your toes will grow much slower than anyone else. Or maybe your eyes are a shade of green that no one else has ever had in your family. Each one of the 100 points will most likely be such a tiny little mutation that you won't even notice it's there. If you're someone who is unconvinced of evolution because you think it all takes millions of years and that we have no proof - this is one example of microevolution, and it occurs right in front of our eyes within a single generation.

It is these tiny changes which may help certain animals in the race for survival. Just the slightest change will make them a fraction more capable of surviving and producing young. Once they produce offspring, they have successfully passed on that mutation to their youngsters, and therefore succeeded at life. I'm talking about natural selection. The natural world only has resources for a certain amount of animals, and as sad as it may be, the majority of wild animals will not survive into adulthood and sexual maturity. It is these slight mutations which will mean one antelope survives longer than its brother. It might have been able to run just a little bit faster due to a genetic mutation which caused it's legs to be slightly longer. These sorts of tiny changes often effect whether or not they will have the opportunity to pass their genes on.

I often have people asking 'If evolution is real, why isn't it still happening? Why don't we see new species all the time?' This is a complicated question. The basic answer to it is that evolution is still happening. In fact, since the dawn of man we have seen the rise of a new species. Most importantly, we more or less 'created' the species ourselves. Man's best friend - the faithful dog. The domestic dog (Canis lupus familiaris) has only been around for a maximum of 30,000 years. That might seem like a long time in our eyes, but by evolutionary standards it's a very short time indeed. There has not been a fossilised dog found earlier than that. If evolution wasn't real, then we would be able to find dog fossils in every single sedimentary layer of the Earth for as far back as we can look. The only explanation is that they descended from another species; the grey wolf (Canis lupus).

If you're still a little sceptical, you only have to think about how we have selectively bred dogs since then, into different breeds. Look at the difference between a Pug and a Great Dane, this could also be considered microevolution. True, they are still the same species, but imagine if we kept them apart for just another 10,000 years. With every single generation adding 100 new mutations, and without the two breeds 'joining' their genetic code any more; don't you think it is conceivable that after long enough their DNA would be so different that they could no longer breed and produce fertile offspring?

A good example of two species which have only very recently separated is the horse and the humble donkey. Most people know that if a horse and a donkey get jiggy you get a mule. Mules can be male or female but they are unable to reproduce. This is essentially what defines a species: the ability for two living things to produce fertile offspring. Although the genetic code of horses and donkey is still very similar (so similar that they can still interbreed); they are different enough genetically that they cannot produce a viable youngster.

In the next segment of this series I will move towards discussing dating methods and the evidence of how old fossils really are. Later on we might delve a little closer into genetics. If you have any particular part of evolution that you would like me to cover please leave a comment.

Throughout this series I will endeavour only to open minds to new ideas. If you are religious, I encourage you to keep your faith, if that is what you would like to do. My only aim is to encourage a healthy understanding of this commonly misunderstood scientific theory.

Stock images courtesy of Tea To Stock & Regu 102.

Wednesday 20 February 2013

Evolution I: Is it really JUST a theory?

This mini-series of blog posts is going to outline the truth about the theory of evolution, and why we often struggle with the concept. These articles are intended to be read with an open, unbiased mind. If you are approaching it with your mind already made up, then the reading of it will be redundant.

'I won't ever tell you what to think; I will only give you the evidence and let you decide for yourself.' - Celia

Part One:

The theory of evolution has been a hot topic of debate ever since it was first publicly proposed by Darwin in Origin of Species, 1859. Since that time, from the very early stages of mass scrutiny and disbelief; to the current widely-accepted theory that it is today; it is still met with scepticism and, often insult, by those who do not understand it.

Firstly, in order to understand the gravity of the theory of evolution, we must first understand what is meant by the use of the word 'theory'. There are varying definitions of the word theory, and it is from this that a lot of the confusion stems. When used in science, the word theory means: a coherent group of tested general propositions, commonly regarded as correct, that can be used as principles of explanation and prediction for a class of phenomena: Einstein's theory of relativity. Synonyms: principle, law, doctrine as defined by dictionary.com

To say that evolution by natural selection is "just a theory" only proves a person's ignorance to the meaning of the term. A theory in science is far from the everyday use of theory which is often used to mean 'idea' or 'concept'. Some believe it would be best to use an entirely different word to describe scientific theory, in order to avoid all the confusion. However, an inquisitive mind and a good textbook will clear up any misconceptions fairly quickly.

If you come across someone who insists on ignorantly parroting the phrase "evolution is just a theory", then you can always gently remind them that electricity is also just a theory; based on electrons which we can't actually see. Heliocentricity (the Earth and planets revolving around the sun) is also just a theory, the fact that our Earth is a sphere rather than flat is just a theory. Even gravity is just a theory. Sure, there are the laws of gravity within the theory of gravity, but all-in-all it is still just a theory.

Understanding what a theory is is fundamental to understanding the reality of evolution. You may not like the idea of evolution, but regardless of whether or not you like it, evolution is going to continue to shape the world around us. I have heard some people state "...if you tell people they are animals they will act like animals..." and they try to insinuate that teaching evolution instead of creationism in schools will raise a society of feral, atheist delinquents. However, deeply religious people have committed some of the most atrocious, deplorable acts of violence against their own kind and against other animals. I am not for one moment suggesting that religion is the source of all evil (and I genuinely don't believe that to be true) but what I am saying is that religion is not the moral source of humanity. If that logic were true, atheists (like myself) would all be criminals, without fail. However, we find our morals through logic and reasoning and understand that it's not nice to harm our fellow humans. We don't require a deity or the threat of Hell to inspire us to do good.

Now that we've briefly debunked a few common myths about evolution, we'll move onto the next topic.

So if evolution is in fact a thoroughly tested scientific theory with a tsunami of evidence behind it, why do we struggle so much to accept it?

Being raised in a devoted Christian household myself, I was taught (through no real fault of my parents) that the theory of evolution was this: butterflies turning into giraffes, and frogs morphing into humans. Obviously, any logical person would scoff at such a preposterous idea. I was informed by my Christian school teachers that the theory of evolution was invented by satanic scientists who wanted desperately to draw God's people away from him.

As a child, one believes what adults tell you. This is only natural, because adults must teach children all the things they need to know. Children will often doubt in their younger years, become curious and try things for themselves. For example, 'Don't touch the stove, it is hot' and yet at first, children will still want to touch the stove; they reach out, and they get a nasty burn. They learn from this, and various similar experiences, that their parents are always right. Later down the track that same principle is applied to anything their parents teach them in regards to religion and morals.

It is often only in one's late teens that questions start arising, you start to challenge everything as your brain develops. However, some people don't go through this stage, and they remain obedient servants to whichever religion their parents brought them up with. I have known many people who grew up in normal, well-adjusted Christian families, who later in life, realised that the Bible just didn't cut it.

We, as humans, often play the role of 'creator'. We design and build houses and cars, produce works of art, bridges, cities and aircraft, the list goes on. We can relate to another 'creator' as being like us. Our primitive brains find solace in familiarity - it's a basic survival instinct, to stay with your own species. This could be one reason we so easily accept that a creator god 'built' everything we see around us. It's a seemingly logical thought for a primitive brain to conceive; not only that but it is a very comforting thought. The idea that an all-powerful being is watching over you is a very comforting thought indeed. However, just because it is a pleasant idea, does not mean it is true.

Throughout this series I will endeavour only to open minds to new ideas. If you are religious, I encourage you to keep your faith, if that is what you would like to do. My only aim is to encourage a healthy understanding of this commonly misunderstood scientific theory.