Here's another blog that's well-worth a visit: Evidence Based Thought. And it's a kiwi blog too!
August 2008 Archives
In the LA Times there's a story about using X-rays of bones to estimate people's age. The reporter's talking about the potential for this technique to obtain fairly accurate ages for those tiny, brilliant, and possibly under-age Chinese gymnasts from the 2008 Olympics. But the underlying anatomical and developmental data have been applied to some equally problematic, but much older, remains - those of the Turkana boy.
Another misleading offering from Icons of Evolution:
VERTEBRATE EMBRYOS. Why do textbooks use drawings of similarities in vertebrate embryos as evidence for their common ancestry -- even though biologists have known for over a century that vertebrate embryos are not most similar in their early stages, and the drawings are faked?
The concept of homology is another of Jonathan Well's 'icons of evolution' - ideas that he wrongly labels as 'key' to teaching evolution, and then describes as incorrect, misleading, or out-of-date. Let's see what he has to say about homology - & why he's wrong.
Wells' second 'question' centres on what's often been called the Cambrian 'explosion' - the seemingly rapid appearance in the fossil record of a wide range of different organisms. ('Rapid' = over a period of 10-20 million years or so.)
While doing a bit of tidying in my office (a mammoth task!) I came across a printout of Jonathan Wells' infamous list, "10 questions to ask your biology teacher". Wells is a senior fellow with the US-based Discovery Institute, which actively promotes intelligent design as an alternative to evolution. His list of questions is (I suppose) intended to sow doubt in students' minds, but what it does very clearly is show his woeful lack of understanding of some fairly basic ideas.
Anyway, I thought I might work my way through them, starting... now.
Of course they can't - they're birdbrains! Right?
Your brain is an energy-hungry organ - even when you're resting, it can use up to 25% of available energy (chimp brains use about 8%: Gibbons, 2007). In other words, the running costs of a large brain are quite high. And yet humans, with their large brains, take in about the same number of calories as similar-sized but smaller-brained mammals. How can this be?
Some of our local letter-writers are quite busy at the moment, pouring out their opposition to the fact and theory of evolution. Sometimes they seem a bit confused about how evolution works, but at others their letters contain an awful lot of misinformation...
[An earlier writer] managed to take the ploy of elephant-hurling (in debate) to new heights, by actually using elephants to 'prove' evolution. (The earlier writer had used the example of increasing tusklessness in African elephants.)
In an earlier post I mentioned that natural selection (hunting pressure) had the potential to increase the proportion of tusklessness in African elephants. But I also noted that this was probably not the full story! And in fact it turns out to be quite a complex tale.
James Burke was a wonderful science communicator (still may be; I don't know if he's still alive). Twenty-something years ago, I remember watching one of his TV series, The day the world changed. It impressed me then, & I wasn't disappointed when I watched part of it again today, having found a link to it via the Friends of Charles Darwin. This particular link is to one episode of the series, looking at what's often called the "Darwinian revolution", but I suspect you could find the whole lot on YouTube if you wanted to go looking.
I've just been talking with some of my students about evolution: fact, theory, process of, the whole lot. And why it's important that people learn about it. I wish I had seen this piece by Olivia Judson beforehand - I could have referred them to it there & then.
And because she says it so well...
When I was a kid one of my favourite books was Old Yellow. Great adventure story - but ends (spoiler alert) with the dog getting shot because it developed rabies. I was so pleased to find out that we didn't have rabies in NZ! Anyway, rabies is caused by a virus, & there's a vaccine for it; you can be given this after being bitten by a rabid animal because it takes a relatively long time for the virus to make its way to your brain (after which, you can forget all about the vaccine, it's too late). But I just found out today that a) the virus gets to your brain via the nervous system; & b) that this was shown by introducing the virus into rats, via a wound in a hind foot, & then (between a day or so & up to 3 weeks later) cutting the sciatic nerve in the affected leg! Now that's an example of scientific creativity in action - how on earth did the researchers (back in 1887) come up with that one? Anyway, go to ERV's place & read the whole story :-)
There's an excellent post (& subsequent discussion) over on Pharyngula, on how to promote 'a scientific mind' - using science, understanding science, enjoying science, knowing how it's done. While some of the comments may refer to the US system, what's being discussed on Pharyngula is relevant to us all - go over there & join in!
When I was at high school, mumblety-mumble years ago, the accepted wisdom was that modern humans and Neandertals were sub-species in the same genus: Homo sapiens sapiens and H. sapiens neandertalensis. That changed, to the view that they were probably separate species, with analyses of new fossil finds. More recently, molecular biology techniques have enabled researchers to compare sapiens & Neandertal genomes. The latest study in this area has reconstructed the Neandertal mitochondrial genome, adding even more support to the idea that these really are two separate species.
Saturday's NZ Herald carried a story under the headline, Locking in the benefits of dieting (along with the almost obligatory picture of someone carrying far too much weight round their middle). Nothing contentious in the research (& I went off & read the original paper too, since the Herald provided a reference) - but it's a good example of how not to talk about your science.
This morning's NZ Herald carried an item on a study into immigrant doctors in NZ practising non-western medicine: how they perceived themselves & their role in patient health, & how their patients saw them. It certainly caught my attention - so much so that I found the original paper on line & looked at that too.
PZ has just posted the video The Genius of Charles Darwin on Pharyngula. It's fronted by Richard Dawkins, & his intention in making this film (part of a series, by the sound of it) is to look at who Darwin was, how he developed the theory of evolution, what that theory is - & why it matters. It's clear, incisive, & pulls no punches. I haven't finished watching it yet, but I can tell you now - it's well worth a look :-)
I was talking with a senior Bio teacher a few days back & she said it would be good if I could deconstruct some of the questions in 90717 (patterns of evolution), as this was an area where her students seemed to have difficulty. I'm not exactly going to do that here. But one of the themes that does seem to come up again & again is the role of the environment in evolution. Hence this post - because it's about a paper that looks at the relationship between the origins of biodiversity and environmental change.
I've been asked to give a general talk to a group of visiting students about Scholarship exams - eek! Anyway, what follows is what they'll be getting (my biology schol presentation without any biology...) The basic details come from the Scholarship section on the NZQA website.
On reading Charles Darwin's blog (yes, really!), I see that the UK government has begun a process of public consultation on science, with the aim of [p]romoting public engagement on increasingly complex science issues and encouraging more people to choose science as a career. Which is an eminently desirable outcome, though how far the consultation process will work towards it will remain to be seen. (I'm somewhat cynical about what is acttually intended by this exercise & - judging by Mr Darwin's comments thread, I'm in good company.)
But I thought it might be interesting to hear what you think. So (using the wording from the UK site), what are your views on the following?
* How to improve communication, generate interest, increase participation and convey the relevance of science;
* How to build trust and confidence in scientific research in the public and private sectors; and
* How to inspire young people from diverse backgrounds to become tomorrow's skilled scientists.
Please write in & share your thoughts. I'm in this business myself & I really, really do want to know!
Another in the occasional series of 'what I'm reading' (actually, there are 3 books on the go at the moment but I've only just started the second & I'm still trying to decide whether or not I like the third). This one is The demon-haunted world by the late, great Carl Sagan.