When I was a research biochemist, I used to enjoy the occasions when I would meet someone new, perhaps in the pub, and they would ask me what I do for a living. Upon hearing the word 'biochemist', you could see their face turn to stone and the panic come over them in a wave as they tried to think of a follow up line that did not involve having to ask what a biochemist is or does. More often than not, this thinking time would rapidly become a tumbleweed moment and I wish I had never said the dreaded B word. Apparently though, if you are a genetic counsellor, rather than a tumbleweed moment, one of the common responses you get is, "so you tell people not to have children then?". And this is how the October Birmingham Café Scientifique started.

Organ donation is always an interesting discussion because it is one of those things that most people, if you were to ask them, do not seem to have an issue with and are generally very supportive of in the UK. And yet we have one of the lowest rates of organ donation in Europe. Why is this? To start to discuss these points, the first thing you need is someone who knows a thing or two about organ donation and the second is a suitable environment for honest and open discussion - welcome to the Birmingham Café Scientifique.

It has been a strange week here at Thinktank Birmingham Science Museum. Without necessarily planning it this way, I seem to have spent a significant amount of time working with neuroscientists and psychologists, which inevitably leads to lots of discussions about the human brain. I have also been electrocuted and attacked by a giant millipede but it is the neuroscience that is actually more interesting.

About 90% of you isn't actually "you". In terms of cell count, a typical human being is outnumbered roughly 10 to one by the microbes that reside in and on their body. You and the microscopic beasts inside you are a complex ecology; mess about with one part, and unexpected things might happen.

When we take antibiotics, we're hammering that ecology, sometimes not for the long-term good of us or the beasts.

There was a truly remarkable article on just this topic in Nature a couple of months ago: "Stop the killing of beneficial bacteria" by Martin Blaser of New York University (Nature 476 pp 393-4; see also article about it in the New York Times.).

At first sight (no pun intended) this is a rather strange question to ask. We all know what we mean by colour and we all generally agree on which colours are which, in which case, how much discussion is there to be had on the subject of 'what is colour?' How wrong could I have been! This month's Birmingham Café Scientifique asked this very question and our guide for the night was Prof Tom Marsh of the University of Warwick, an astrophysicist by trade. Not only is the concept of colour very important to him professionally, but he also has a keen interest in the human psyche and our perceptions of colour.

Bacteria can help kill cancer cells! That's what the headlines said on Monday, but did you know that microbes - the things we are often (wrongly) told to steer clear of - have been known to have an effect on cancer cells for hundreds of years?

It's my job to keep on top of all the news stories about microbiology. So anything about bacteria, viruses, fungi - if you can't see it, I need to know about it.

It was very interesting to read Jack Cohen's article on the demise of Archaeopteryx: in it he highlighted a worrying issue - that of the need for certainty in our society. All good science and scientists are in the business of 'changing their minds' - that is, continuously developing theories that are the best stories we can tell that offer the simplest description of the available evidence.

Maybe you've never heard of Archaeopteryx. But it's held a special place in the theory of evolution for over 150 years. The word means "ancient wing", and it's the name of a strange fossil, half-bird and half-reptile; it had, for example, both feathers and teeth.

A German miner found the first one in 1861, two years after Charles Darwin published The Origin of the Species. It was considered by many to be a perfect "missing link" in his theory of evolution by natural selection. Indeed, it's been a mainstay of his theory.

Until recently, that is.

Several years ago, an unusual article appeared in the science journal Nature that caught my eye. It could have been the picture of the armadillo, or the word 'penis' (unusual in high end scientific literature!) that I noticed first, but the combination of the two was surely a recipe for a good story. It was an article about a research group that studied penis structure, using the armadillo as their model animal. Whilst the article was interesting, there was an entertaining section at the end on why armadillo was chosen as the model for this work; armadillos are found in the roadkill lining the highways of Florida.

Last week in Nature there was a very illuminating paper, called "Controllability of complex networks" by Liu, Slotine and -- particularly -- Barabasi.

Albert-Laszlo Barabasi has been in the complexity field for many years, and has brought illumination to many areas, from engineering and natural systems like ecology to complex social systems. (He also writes compellingly good books for the non-scientist.)

The idea of 'controlling complex systems' seems much too general to do any real mathematics with, but the authors of the Nature paper show very clearly that