The earliest fossils we have are of prokaryotes – a major taxonomic grouping that includes both bacteria and members of the Archaea (things like blue-green algae, aka cyanobacteria). And like modern prokaryotes, those early life-forms were tiny. Most of us are far more familiar with some of the eukaryotes, and perhaps a major reason for […]
Continue readingMonth: January 2009
eat a species – and change it
One of the questions in last year’s Level 3 Bio exam asked students to consider the impact of human predation on fish evolution. Most fish stocks, in New Zealand & around the world, are intensively harvested by fishermen. The mesh sizes used in their nets mean that the fish they catch are mostly the larger and […]
Continue readinglouisiana & intelligent design
For those who don’t necessarily read the ‘comments’ & so may have missed Heraclides’ heads-up – in the US the education board in Louisiana has made it possible to teach intelligent design in the state’s schools: On Tuesday, the state’s Board of Elementary and Secondary Education adopted a policy that sharpens those fears, giving teachers […]
Continue readingdoes drinking coffee lower the risk of developing alzheimer’s disease?
"Gosh" said my husband, rustling the newspaper. "You’d better start drinking coffee!" He’d just come across a report saying that drinking more coffee in one’s middle years is associated with a decreased chance of developing Alzheimer’s disease, or other forms of dementia, in old age. But is this enough to make me want to give up my […]
Continue readingthat’s not what the textbooks say should happen!
Islands can be home to rare and unusual species, which have often evolved in isolation for extremely long periods of time. On many – particularly oceanic islands – there may be no native land mammals, except, perhaps for bats. So when mammalian predators do make it to these islands the effects can be devastating. (Incidentally, […]
Continue reading‘scientifically proven’ – I think not
The phrase ‘scientifically proven’ is not one you’re likely to hear from a scientist – but it’s often attached to claims about a whole variety of products. Why don’t scientists use the phrase? Because – as I’ve said before – while we can offer the best possible explanation for a set of data or suite […]
Continue readingnatural selection and chemical replicators
Perhaps one of the biggest unanswered questions we have is "how did life begin?" Scientists have been working in the area of abiogenesis for some time now, beginning with the Miller-Urey work on the early-Earth atmosphere (which I’ve commented on previously). And there’s reasonable agreement that the precursors to life were probably some sort of […]
Continue readingenough with the sainthood, already
There’s a new geology book coming out, written by a group of geologists and examining the geological evidence for evolution (& the lack of support it offers to creationism). It sounds like a good book & I’ll look forward to getting my hands on it (hopefully one of my geology colleagues will buy a copy!) […]
Continue readingthe ‘origins’ blog
This year there’ll be a wide variety of events & publications marking the 200th anniversary of Charles Darwin’s birth. One of these is Origins: a history of beginnings, a blog on the website of the journal Science. It kicks off with a post by science writer Carl Zimmer (I’ve talked about some of his other work here & […]
Continue readingsnowball earth
For anyone with a passing interest in global climates, present & past, the UK’s Birmingham University has put out an excellent article looking at the conditions that could have prevailed on a’snowball Earth’. The term ‘snowball Earth’ refers to a time (about 630 million years ago) when our planet was in the grip of a major ice […]
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