As a fair few people will have noticed, it seems that there are several patterns that pop up over and over again through history.

In particular, I'm talking of the "Boom and Bust" pattern, the most recent notable example of which is world-wide economy. Although I don't personally recall any other recessions, largely because I wasn't around for them, I am all too familiar with the Wall Street Crash, and the Great Depression, and other such terms bandied about in a year eleven history class.

As most will know, the latest downturn in the British and, I'm told, Worldwide economy follows closely a period of economic success (although the NHS might not see it that way).

Glance back to the end of Hoover's reign in late 1920s, and there was a boom - unregulated speculation on the stock market meant people were spending money that they didn't have, blindly confident that they would have it in the future. Suddenly, they weren't getting the money back, and the whole thing spiralled into a truly horrific economic crisis.Several countiries printed more money to deal with the general lack of it, which led to its rapid devaluation, and, although the depression was worse in germany for a number of reasons, I distinctly recall images of children in germany building playhouses with bricks of money.

And now, as if you haven't heard enough about it - the credit (or as I call it debt) culture in the UK means that people are spending what they want, not what they have, and assuming that they'll have it by the time they need to pay it. Add to that that a good deal of people don't actually own the houses they call their own, and yet are selling houses - at massively inflated prices - to buy others, in the assumption that, one day, they'll have the money to pay it back, and you have a very novel take on the stock exchange. It's the real estate exchange, and there's very little real about it.

But this boom and bust tradition is not limited to the economy. While the phrases might apply differently, even volcanos fit it quite well - the longer the period of dormancy, the bigger the bang at the end of it equates nicely to the longer a boom goes on, and the bigger it is, the deeper the recession at the end of it will be.

And being a zoology student, I am well aware of another boom with an overdue bust, and so, on that note, I shall switch to the biological take on boom-to-bust. If that doesn't appeal to you one iota, I suggest you skip the next section and head straight to Hypocriticism

Although Boom and Bust is typically considered in terms of the economy, it is far more common in ecology. The most obvious example is in density dependent selection - any animal breeding too prolifically will, at the very least, attract the attention of predators, who will themselves breed prolifically to make use of the available plenty. In case you were wondering, this is still boom. They then eat the prey in vast, often too vast, numbers, which is the bust for the prey animals, and then starve themselves. Alternatively, as with lemmings, a herbivore will breed too fast, eat all the available food and starve to death. It has been suggested, although I can't verify it, that the supposed mass suicides, if they do indeed happen and were not just a work of animal cruelty by Disney, are in fact the results of a vast number of Lemmings heading along a migratory path to more food at a desperate pace, and a slightly wrong heading, combined with the push of the crowd and their small stature, could mean that very large numbers could discover that they were approaching a precipice a little too late to do anything about it.

A more subtle version of density dependent selection is by disease. It has occurred several times before in human history - whenever a city became to crowded, disease could spread faster and so incidents like the black plague considerably reduced the human population.

Normally, incidents like this occur when a growing population is looking for its carrying capacity, or the maximum number of individuals that can be supported by the environment. The normal situation, then, is for the population to overshoot its limits, and then, thanks to density dependent selection, fall back down again, and then grow, until eventually they settle upon their carrying capacity. In some cases, such as that of the European rabbits that found Australia and various other countries so much to their liking, their boom period will be so harmful to the environment that they actually change the carrying capacity to somewhat lower than it was if they hadn't overshot it so much, and so they stabilise quite a way below where they could have, if rabbits knew about contraception.

And, in case you were wondering, this is what is overdue with humans.As much as I long to sit on a high horse and hypocriticise (and even if that isn't a word, I shall be doing it in a minute), there are still a number of boom-and-bust situations I need to point out.

As well as population size, the size of individual animals also follows this pattern. With a few exceptions, big is very often better, as, if you're a prey animal, it makes you vulnerable to less predators, and if you're a predator, it makes more things vulnerable to you. Add to that that a bigger animal is often better at beating off the competition during mating season, and you find that most life has a tendency to get bigger.

Theoretically, physics imposes limits. An animal hefty enough might not have the bone strength to support its body on land, but as far as we can tell, no species has yet spontaneously crumpled to its knees because they won't support it any more (although any number of factory farmed chickens have). On top of that, the single heart possessed by most vertebrates has trouble pumping blood a particularly long way and back again, so you change the heart - you make it more powerful or, in the case of the blue whale, the size of a small car. But, for land animals at least, a more powerful heart presents difficulties - the energy required to pump blood up to a head a long way above a heart could easily be fatal is the head stopped being above the heart, and most everything needs to put its head down at some point.

But, as always, on the way to being big, you'll almost certainly have encountered these difficulties in a lesser form, and those who can't cope will have been weeded out by the dedicated gardener that is natural selection.

But big, even though most life on earth hurtles towards it as fast as any number of legs, fins or wings can carry it, is not always better. A large body is harder to support - insects, with a rather inefficient way of getting oxygen from the air, noticed this quite early on - and you need a lot more food to keep a much bigger animal going.

Which means that what is good when there is plenty is bad, very bad, as soon as times get even a little tough. While smaller animals subsist on what little they can find in a drought or famine, bigger ones must leave or die.

Even natural selection itself runs on a boom-and-bust-based fuel. A period of low selection pressure (or a period of plenty) leads a species to become prolific, and in that prolificness, there is variation. Then put pressure on the species (or introduce a new predator, or climate change) and if your variation means that this isn't a problem for you, you're instantly in the next time of plenty for the whole cycle to start again.

So, for those of who are almost enthusiastic about biology as me, that is boom and bust in general biology. Or rather, general biology in boom and bust.

For those of you who skipped the long middle section, I am aware that hypocriticise is probably not a word. But I'm going to do it anyway.

Boom and Bust, you see, is particularly worrying when it comes to humans, because we've been in a period of fairly unsupported boom for quite some time now, and are well overdue our biological bust, and so overdue that we'll probably come out of it a lot worse than we could have done.

Why do I believe this? The answer is Hedonism. We have lived for today for quite a few too many days, and the environment is beginning to suffer the consequences. Fish stocks, almost worldwide, aren't a fraction of what they used to be, and that is not, Canada, the fault of the seals, it is the fault of the commercial fishing vessels, with a relatively minor added effects of pollution (which should not be taken lightly - it's just that, of all the things we're doing to the ocean IN GENERAL, it's one of the less truly horrific). Once fertile soils, thanks to intensive farming methods that we have known for a very long time indeed to be flawed, are now scarecely capable of supporting ground-elder without the expensive addition of chemicals.

So it is safe to say that we have already changed the environment negatively. I say this from a purely scientific point of view and without any prejudice, but on top of this, we seem to be giving the laws of nature the finger and daring, nay, inviting an epidemic to wipe us out. We congregate in ever larger cities, and our accelerated lifestyles that even a rapidly fatal disease like the ebola virus could cross the globe before anyone noticed the symptoms. If such a disease was to enter general circulation, by the time anyone could do anything about it,  it would be too late. Unlike the banks, you can't throw money at someone with ebola and put off the problem for another two years. If ebola did enter general circulation without a reduction in fatality, I wouldn't give general society two weeks before boom had turned to a total and disastrous bust.

As if that isn't enough, a good deal of our boom (from this Germany and other countries whose major source of energy is not fossil fuel) is non-renewable, at least in the short term. Even with the Three Gorges Dam working at full capacity, our current society would change considerably if we found ourselves without fossil fuels tomorrow.

Now, I consider that an overstretched conclusion, so to sum up, here's a short one:

BUST.