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 head). Another group of scientists, including those who first discovered and described the remains, regards them as belonging to a dwarfed species, most probably descending from Homo erectus.
September 2007 Archives
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.
As I was reading the Saturday morning paper, a full-page ad caught my eye. Auckland War Memorial Museum is hosting an exhibition on Charles Darwin, and it opens on September 29. Yep, I'll be going!
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.
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.
The camera-type eye of humans (& in fact all vertebrates) is often held up as a classic example of what ‘intelligent design’ (ID) proponents call irreducible complexity. The argument goes like this: a) the camera-type eye needs all its parts to function. b) It couldn’t possibly be assembled randomly as Darwinian theory claims. c) The eye thus supports the concept of intelligent design. After all, Darwin himself commented that “To suppose that the eye, with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest possible degree” (1859, “On the origin of species”).
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...
Being male can be a risky business. In a butterfly called Hypolimna bolina, there's a rather nifty bacterial parasite called Wolbachia that has unfortunate effects on male butterflies. It's carried down the maternal line and kills off male embryos. Just the males. This can result in some pretty skewed sex ratios. (And presumably an interesting, albeit exhausting, time for the surviving males.)
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?