Scientists have thought for a long time that tree shrews are the closest living relatives of primates. More recently, use of DNA data together with morphological comparisons suggested that colugos are also very closely related to apes, monkeys (& us). These so-called 'flying' lemurs use extensive flaps of loose skin, stretched between their outspread front and back […]
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evolution & the nature of science
I like to teach my students here at Waikato something about how the theory of evolution was developed. OK, I'm interested in history anyway, but it's also a really good way to teach about the nature of science. You know; what is science, really? What does the word theory mean to a scientist? How's science done? Well, […]
Continue readingUsing human evolution to illustrate patterns of evolution
Sometimes we think of human evolution as being distinct from the evolution of other animals. I think it important to remember that it's not, and that our own evolutionary history follows the same patterns, and is shaped by the same processes, as the history of all other living things.
Continue readingDarwin at the museum
Well, I've finally made it up to Auckland, to go to the 'Darwin' exhibition at Auckland War Memorial Museum. And it's as good as I'd hoped. If you live in Auckland, or you're visiting, do try to go & see it. It's a wonderful walk through Darwin's life and through his development of the theory of evolution.
Continue readingEvolution – micro, macro, what’s the difference?
You'e probably come across the terms 'microevolution' and 'macroevolution'. 'Microevolution' is generally taken to mean small-scale changes in a population's gene pool, while 'macroevolution' is evolutionary change at the level of species, or genus, or phylum. This distinction can cause problems with understanding…
Continue readingSexual signals and strong, silent males
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 […]
Continue reading“Punk eek” and speciation
The concept of punctuated evolution – bursts of evolutionary novelty separated by long periods of stasis – was first proposed by Stephen Jay Gould & Niles Eldredge in 1972. Since then, there's been an ongoing debate among evolutionary biologists about how significant ‘punk eek' could be in the evolution of new species. (Remember that they aren't […]
Continue readingCharles Darwin, I presume?
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!
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 readingThe improbability of an eye… (‘intelligent design’ part 2)
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 […]
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