What good is a genome anyway?

September 30, 2009
I read an interesting post by Olivia Judson at the New York Times blog a few weeks ago, which asked if you could sequence any genome, what would you choose?  Olivia’s choice was the coelacanth– a worthy choice, given that the coelacanth may represent the ancestor of all tetrapods (the amphibians, reptiles, birds and mammals).  No prizes for guessing what my choice would be…

Anyway, this got me thinking.  What good is a genome sequence?  What is it going to tell us about our favourite organism that good old-fashioned biological enquiry and lab work hasn’t been able to tell us so far?  Whenever the idea of sequencing the tuatara genome is discussed, one of the major questions that comes back (especially from non-geneticists) is “why?  Even though genome sequencing is getting faster and cheaper by the day, it still requires huge resources of time and money and it’s not always obvious why its worth going to the effort.   Read the rest of this entry »

Something funny for a Friday afternoon

September 25, 2009

Irish comedian Dara O’Briain talking about science, journalistic “balance”, homeopathy and other things

Thanks to Open Parachute for posting this and making me laugh on a slow friday afternoon.

Pesky reptiles confuse palaeontologists

September 17, 2009

This from a letter to Nature, in the latest edition:

Could Nature have been unknowingly publishing papers for the past 80 years about crocodilian gastroliths (stomach stones) instead of stones concluded to be 2.5-million-year-old hominid tools? This possibility could cast doubt, for example, on the nature of the Oldowan specimens described by Michael Haslam and colleagues in their Review of primate archaeology (Nature 460, 339–344; 2009).

…Identification of the Oldowan specimens as tools is based on the fact that the soft relict sands of Olduvai Gorge contain no natural stones of their own, so any stone found there must have been moved from distant river beds by some unknown animal transporter — concluded by high science to be Homo habilis. But crocodiles have the curious habit of swallowing rocks: these account for 1% of their body weight, so for a 1-tonne crocodile that’s 10 kg of stones in its stomach at all times. Surprisingly, science has never even considered the crocodile as transporter.

Read the full version here

Warrior genes and the disease of being a scientist

September 15, 2009

The past few days, headlines like “Maori don’t have warrior gene” and “Maori warrior gene debunked” have been all over the media. This has left me with a sinking feeling in the pit of my stomach, and thinking that this sounds a lot like media hype/oversimplification of what is a very complex area of research.  To recap…

Back in 2006, Rod Lea gave a presentation at the 11th International Congress of Human Genetics showing that Maori have a higher frequency of a particular variant of the Monoamine Oxidase-A (MAO-A) gene.  In some studies, this particular variant has been linked with aggression and antisocial behaviour, and one study back in 2004 dubbed it “the warrior gene”.  The media picked this story up, and bandied around headlines like “Warrior gene blamed for Maori violence”, making statements claiming that “New Zealand Maori carry a “warriorgene which makes them more prone to violence, criminal acts and risky behaviour”.  This is not what Lea and colleagues claim in their original study at all – I’ll talk more about that below.

Anyway, now according to media reports this claim has been “debunked by science”.  When I read this my initial thought was that someone has done another study of Maori MAO-A allele frequencies, and found conflicting results.  But actually this is not the case at all.  The “scientific study” that debunks this claim is actually just a review by Maori academic Dr Gary Hook, published in Mai Review – a peer-reviewed journal of Maori and Indigenous development, but not a scientific journal.  Hook makes some good points, which I’ll talk more about in a minute, but presents no new data and much of his review of the scientific controversy has already been covered in a previous article.

Read the rest of this entry »

Bird sex gene identified

September 11, 2009

ResearchBlogging.org In mammals, sex is determined by genes contained on sex chromosomes – males have an X and a Y chromosome, and females have two X chromosomes.  In birds things are quite different, as it is the male that has two of the same type of sex chromosome.  Male birds have two Z chromosomes and female birds have a Z and a W chromosome.  In mammals, the Y chromosome contains a gene called SRY, which “switches on” the male sex determining pathway.  So if you have the SRY gene you develop testes, and if you don’t you develop ovaries. 

Until now, the identity of the master sex-determining gene in birds has been a mystery.  The Z and W chromosomes of birds are not related to the X and Y chromosomes of mammals, and birds do not have an SRY gene.  Research published in Nature yesterday appears to have solved this mystery, with evidence that the DMRT1 gene, located on the Z chromosome, is the bird sex determining gene.  Read the rest of this entry »

Protected minke whales from unreported bycatch sold on Japanese markets

September 6, 2009

ResearchBlogging.org Japan kills over a hundred minke whales each year under the guise of “scientific whaling”, and much of the meat ends up in the commercial markets destined for Japanese dinner plates.  Now a study just published in Animal Conservation indicates that a similar number of whales are killed as “bycatch” in Japanese coastal waters, and much of this catch is unregulated and goes unreported.  

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