Just finished reading The Oxford Book of Modern Science Writing, a collection edited by Richard Dawkins. Though I’m not too keen on his militant atheism, for once he manages to rein it in and concentrate on the excellent science writing. The extracts selected are all great choices; some from works I’ve read previously, some I wanted to read, and some I wasn’t aware of. The brief comments by Dawkins introducing each are also insightful, and help give valuable context. Best of all it was only £6, bargain!

Scientists find key human language gene

This is an article I originally wrote for Wikinews here.

Rendering of the FOXP2 protein
Rendering of the FOXP2 protein

Researchers have found a crucial genetic difference between humans and chimps that could help explain our language and speech abilities. The difference lies in a gene called FOXP2 which encodes for a protein of the same name. This acts as a transcription factor, controlling the activity of other genes.

The human and chimp versions of the protein differ in only two of their 740 amino acid components, but when researchers at the University of California, Los Angeles, replaced the human gene with the chimp version in neurons grown in the laboratory, they found it affected the expression of at least 116 other genes.

The results are detailed in a paper published on Thursday in the scientific journal Nature.

Author of the study Dr. Daniel Geschwind, of the David Geffen School of Medicine at UCLA, said the gene had a “major role” in differences between chimps and humans. “We showed that the human and chimp versions of FOXP2 not only look different but function differently too.”

Some of the affected genes control the formation of connections in the brain, whilst others relate to facial movements. Several have already been found to be involved in language disorders. Mutations in FOXP2 itself were also known to affect speech and language; the gene was first identified in members of a family suffering from language problems who were found to share a genetic mutation.

Frances Vargha-Khadem at University College London has studied patients with FOXP2 mutations, and agrees with the new research. As well as language problems, some of her subjects have changes in the shape of their jaws, mouths and tongues. She thinks that chimps may also have these differences.

“We believe FOXP2 is not only important for the higher order cognitive aspect of language but also for the motor aspect of speech and language,” said Genevieve Konopka, one of the authors of the paper at UCLA.

Previous research indicates that the changes in FOXP2 occurred around 200,000 years ago with the rise of modern humans. Geschwind also suggests that several of the related genes may have evolved together. Preliminary studies have shown signs that they too emerged relatively recently.

Scientists are now keen to further study FOXP2 and the genes that it affects. Geschwind believes this could eventually lead to breakthroughs in treatment for disorders such as autism and schizophrenia, which affect language skills.

The study was funded by the National Institute of Mental Health, the A.P. Giannini Foundation and the National Alliance for Research on Schizophrenia and Depression.


External links

Parallel worlds

I’ve been messing around on Yahoo! Answers recently. Someone asked the question “Why do some physicists think parallel worlds might exist?” I spent far too long on my answer (especially since the fun parts of quantum physics won’t be on my upcoming exams!) but am fairly pleased with it, and it took me back a bit to when I was studying such things. Answer reposted below:

That’s what is known as the “many-worlds interpretation” and is one of the ways scientists try and think about the baffling world of quantum mechanics.

The classic experiment and the best way to explain is the double-slit experiment. Imagine you have a plate with two narrow slits cut in it. You have a light on one side, and a screen on the other. When the light shines through one of the slits, it produces a diffraction (spreading) pattern. When it shines through both slits, there are two diffraction patterns which interfere with each other, producing a different interference pattern. This is typical for waves, and you can show a similar effect with ripples on water.

Now it is also known that light occurs in indivisible “packets” called photons. If you decrease the intensity of your light source you can get it to emit only one photon at a time. But you still get the interference pattern on the screen! Why is this weird? Because if you only sent one photon at once, what is it interfering with? The quantum answer is that it interferes with *itself*!

Somehow the single photon must have passed through *both* slits. There are a few ways to think about this. One basically says that it is impossible to know which slit the photon went through, and therefore it went through both. Unfortunately this basically means that the photon no longer has a position you can pin down, which is a bit weird. This is just like Schrödinger’s cat being in a box where you can’t tell if it’s alive or dead, so you say it is both at once. [1]

So as an alternative to that weirdness, some scientists [2] thought up an explanation just as weird, if not more so – the many-worlds interpretation. In this version, the photon remains localised (i.e. it has a defined position). But the universe splits! In one universe the photon goes through the left slit, and in another it goes through the right one. We only see what happens in one universe, so we think photons stay localised. And then somehow on the other side, the two universes interfere with each other to give the pattern. This is like saying Schrödinger’s cat is alive in one universe, and dead in another.

Hope this helps, and apologies for the length, it’s pretty complicated to explain and I got a bit carried away! There’s more info about the many-worlds interpretation here:

“…those who are not shocked when they first come across quantum theory cannot possibly have understood it.” – Niels Bohr

[1] Schrödinger didn’t actually believe in his cat, it was just an example to show how weird quantum mechanics is
[2] Fun fact, the guy who proposed this first was the father of Mark Everett from the band Eels.

Random article: Faddeev-Popov ghost

Things like this make me wonder if quantum physics isn’t all a hugely elaborate practical joke by scientists on the rest of us mere mortals. Negative probabilities? Seriously?

In physics, Faddeev-Popov ghosts (also called ghost fields) are additional fields which need to be introduced in the realization of gauge theories as consistent quantum field theories.

The Faddeev-Popov ghosts are sometimes referred to as “good ghosts“. The “bad ghosts” represent another, more general meaning of the word “ghost” in theoretical physics: states of negative norm—or fields with the wrong sign of the kinetic term, such as Pauli-Villars ghosts—whose existence allows the probabilities to be negative.