On hot summer nights male crickets chirp constantly in their attempts to attract mates, rubbing a toothed ‘file' on one forewing over a ridge on the other forewing to produce their song. But this can be a risky business, as it might not be only females who are drawn by the males' calls. Predators and […]
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Climate change and human evolution
Models of human evolution give quite a bit of attention to the role that climate change may have played in the evolution and dispersal of hominin species, both ancient and modern. A study just published presents evidence of an extreme and prolonged drought in East Africa, spanning 135,000 – 75,000 years ago – the time when the Out […]
Continue readingGene targeting technique wins a Nobel Prize
Just a quick link to an article this time – the 2007 Nobel Prize for Physiology/Medicine has been awarded to the scientists who developed the technique of gene targeting. This has allowed scientists to 'knock out' single genes, & by doing this to work out their function. My favourite science blogger, Orac, has just posted […]
Continue readingNew paper on floresiensis
Ever since the 'hobbits' (Homo floresiensis) were discovered in 2003, on the Indonesian island of Flores, there has been an on-going debate about their exact relationship with our own species. One interpretation of the fossils sees them as members of our own species, with the most complete individual (LB1) having suffered from microcephaly (ie an abnormally small […]
Continue readingDiet and your genes
Modern molecular biology has allowed us to look ever more closely into the genetic changes associated with human evolution. A recent research project used this technology to examine a possible relationship between diet and genome.
Continue readingmarathon man, part deux
Possession of an Achilles tendon is only one of the things that sets humans up for endurance running. Bramble & Lieberman (2004) note that long-distance running requires a whole suite of adaptations for skeletal strength, stabilisation, thermoregulation, and energetics. I'll summarise some of their comments here.
Continue readingmarathon man?
I was looking through the SciTech Daily website (a good place to go for new reading in a whole range of science areas) when I saw the link to an article on the evolution of running in Homo. Followed it, read the article – & thought, this is really interesting.
Continue readingThe nature of natural selection
If you've gone through the Schol Bio exam papers from previous years, you'll have noticed that evolution is one of the key themes in every paper. So I thought it could be useful to spend a bit of time on concepts relating to natural selection, one of the drivers of evolutionary change.
Continue reading“intelligent design” – science or philosophy?
At my scholarship preparation day yesterday I was asked if students could expect an exam question about evolution and intelligent design. My answer? No, because "intelligent design" is not a scientific explanation for the diversity of life on earth. My reasons for saying this? Read on…
Continue readingStudent query: gene sequencing
James has asked: in gene sequencing, since the dd_PP will have made a cut every base, in order for us to read the sequence, how is it possible for us to read it using electrophoresis when the distance between these bases will be around 0.01 of a nm?
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