n July this year, the Seattle Times ran a story on an orca called Tahlequah – she was pregnant, again. And just yesterday, she gave birth. The story is particularly noteworthy because a couple of years ago, Tahlequah also bore a calf, which died, and she then carried the dead baby on her nose for […]
Continue readingCategory: genetics
neandertals’ genetic legacy extends into africa
For the last few years it’s been pretty much received wisdom that African populations shared only a tiny proportion of their genes, if any, with Neanderthals. In contrast, other non-African sapiens populations had a small but significant admixture of Neanderthal genes. The underlying reason for this, it’s been assumed, is that Homo sapiens and neandertalensis only bred with […]
Continue readingzombie ants, updated
Image source: David P. Hughes, Maj-Britt Pontoppidan – http://www.plosone.org/article/showImageLarge.action?uri=info:doi/10.1371/journal.pone.0004835.g001 CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=17917778 Back in 2010 I wrote about the strange tale of the zombie ants, which do the bidding of their fungal overlords. (They’re not an isolated example; a range of parasites change their hosts’ behaviour. See here and here for example – though as you’ll find, […]
Continue readingtelling good science from bad (a cautionary tale)
Recently I came across the claim that cystic fibrosis (CF) can be cured by diet. This was news to me, given that the mutation that causes CF is well-documented, as are the necessary treatments, and I wasn’t aware of any evidence that diet alone would correct the faulty membrane pump involved. So I said so. […]
Continue readinga new study on the heritability of autism spectrum disorder
Science has known for a while now that there is a strong genetic component in autism spectrum disorders (ASD), although those opposed to vaccination tend to deny this. (David Gorski points this out in his commentary on this new 2019 paper.) In this paper, Bai et al. cite data from a meta-analysis of twin studies that […]
Continue readingthoughts on a question about kākāpō
My interest in kākāpō way back in my honours year at uni: a guest speaker told us that as far as anybody knew, the last remaining birds were a few males, somewhere in Fiordland. I remember feeling that that sounded really sad – those lonely males booming for females who never came. Shortly after that, […]
Continue readingcave bears and brown bears and and admixture, oh my!
Last week the story of a hybrid hominin was in the news: the discovery that remains found in Denisova Cave were those of a 13-year-old girl whose parents were a female Neandertal and a Denisovan male. This was exciting stuff: we already know, from genomic analysis, that interspecies matings involving Neanderthals, Denisovans, and H.sapiens happened […]
Continue readingslick propaganda has no place in science classroom
Except, perhaps, if it’s used to develop critical thinking skills. But I don’t think that’s what happened on the occasion reported under the headline Creationism taught in science class at Villa Education Trust school: [A student who’d studied at] Mt Hobson Middle School said Darwinism was taught as an unproven theory and students were shown […]
Continue readingducks, domestication, and selection’s signature
I’ve always rather liked ducks, ever since we hand-reared some ducklings back when I was still a school-kid. Mind you, the innocent me of those days didn’t know what I know now about the effects of sperm competition and sexual selection on their reproductive organs. (Those of an enquiring mind will learn more – much […]
Continue readingcould – & should – the moa be a goer again?
I’m starting to gear up for some Schol Bio preparation days in the regions (hi, Hawkes Bay! See you in 4 weeks!) and realised that I haven’t written anything specifically focused on those exams for a while. So I thought that putting something together would be a good way to spend a rather wet Sunday. […]
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