Doomed Planet

Off to Paris with a Sex-Change Lizard

lizard beardedFor what quite likely has been at least several million years, the bearded lizards that make their home in the arid country around the western Queensland town of Eulo have maintained a low profile, devoting their days to darting under rocks and generally minding their own business. To the extent we know and understand how the creatures feel about humans, avoiding contact would seem to be the extent of it, which demonstrates once again Mother Nature’s wisdom. After allowing themselves to become the focus of expeditioning academics and, via them, the crusading reporters of the ABC, this inoffensive reptile has been dragooned to serve as the latest, globally acclaimed poster specimen for all manner of fashionable causes.

The lizard’s neat trick is the ability to change sex according to the temperature of the nest in which the egg from which it will emerge is resting. While the ease of this operation might make Bruce Jenner, now identifying as Caitlyn, somewhat jealous, it had a galvanic effect on the ABC, which gave the obscure lizard pride of place in news bulletins throughout Thursday, June 2.

Not only did the sex-change lizard serve as an implied reminder that gender is a societal construct – Male bearded dragons that change sex make better mothers, study finds – the various stories also hung their headlines on the climate-change angle. This was to be expected, as global warming cops the blame for everything from walrus stampedes to reluctant prostitutes, rapacious cannibals and the Atlantic becoming more salty or less salty, presumably according to researchers’ tastes.

Quadrant reader and contributor Peter O’Brien did find something odd about the news reports, however: there was nothing new about them. He writes:

“While the ABC hyped the potential for global warming to eventually cause this species’ extinction, something about the topic rang a bell so I did some googling. To my not-quite-surprise, I quickly discovered an article in National Geographic  from 2007 which appeared to describe a very similar research project and outcome, also conducted by the University of Canberra.

Delving further, it seems the significance of the latest research is that this is the first time the sex change mechanism (called TSD) has been observed in the wild rather than in a laboratory.  Nonetheless, I find it almost beyond belief that the 2015 observation of this phenomenon could come as a ‘shocking discovery’ when it had already been canvassed eight years earlier.

The researchers examined 131 lizards of which 11 exhibited the sex change, i.e. they had male chromosomes but were female in all other respects.  Not a particularly large sample.

In a globally syndicated Associated Press story, re-printed in The  Australian and many other media outlets, it was reported that ‘the team also found that the offspring of these dragons no longer have their gender determined by chromosomes, but by temperature. This is happening in an area described as (my emphasis) “one of the fastest warming places in Australia over the past 40 years,” [lead author] Claire Holleley said. “‘Lab tests show that the switch from genetic sex determination to temperature sex determination seems to start at about 32 degrees Celsius and occurs 100% of the time at about 36 degrees Celsius,’ Holleley said.”

Considering the question of possible extinction due to global warming, I started to think about why the lizards have this capability.  Presumably, it is a survival mechanism.  But in what way would it be advantageous to have more females in a warmer world?

It seems, we don’t know the answer to that.  Wikipedia is not a source I would normally trust in any consideration of climate change but this entry seems objective enough.  It states, in part,

‘….recent phylogenetic comparative analyses imply a single origin for TSD in most amniotes around 300 million years …. Consequently, the adaptive significance of TSD in all but the most recent origins of TSD may have been obscured by the passage of deep time, with TSD potentially being maintained in many amniote clades simply because it ‘works’.’

The idea that a species that has survived for  millions of years, during most of which period the world has been warmer (at times up to 10C) than it is today, could become extinct because of a few degrees warming now, seems hugely counter-intuitive.

The fact that researchers found that sex change occurs 100 per cent of the time in temperatures of 36C (which would not be uncommon in Queensland) in the laboratory, is neither here nor there.   Whatever their survival mechanism, presumably bearded dragons would have the ability to choose a nest with optimum temperature.  I suspect that the survival mechanism of bearded dragons is infinitely more complex than these researchers imagine.

And the comment that these changes are occurring in ‘an area that is one of the fastest warming places in Australia over the past 40 years’ has all the hallmarks of warmist propaganda.

Alarmists often state that it is not the end point of warming that is critical to the extinction of a species but the rate of warming, the implication being that natural evolution cannot keep up with the horrific rate of warming we are currently experiencing.   Here is an interesting study, relating to lizards, that shows this is not always (if ever) the case.

It observes that a species of Italian wall lizard introduced to a Croatian island, in just a few decades developed a completely new gut structure, larger heads, and a harder bite.

Would it be too cynical of me to wonder if this research, interesting though it may be, has been positioned in the media just to give added impetus to the CAGW hysteria as we approach the Paris climate change conference?”

Not too cynical at all, Peter, especially in light of that tossed-off claim about the Eulo region being “one of the fastest warming places in Australia.” The weather station at Eulo stopped reporting in 1997, so that sheds no light, but a mere 64km distant — and well within the bearded lizard’s home turf — is Cunnamulla, where daily records continue to be maintained. According to the site’s spreadsheet the most recent record-breaking day was in 2004, with other highest-temperature readings for various months dating to 1958 and 1965.

Yes, indeed. Lizards may switch their sex  at the drop of a hat, but alarmists never change their spots.

  • Ian MacKenzie

    Surely the main problem with this is the shear geographic range of bearded dragons. I had them in my garden in Mount Isa in the 1990s where temperatures regularly exceed 40 degrees in summer. I still have them now in my garden in central NSW, where there was a frost this morning, although they’re not very active at this time of year. I realise that there are a number of different species of dragon, but clearly these animals are well adapted to a wide range of environments and climates. If climate change were to occur and temperatures increase, the worst that could happen would be that their range might move further south or to higher altitudes. However there doesn’t seem to be any evidence that dragon populations are under particular stress at the northernmost, hottest part of their range. Certainly the many I saw in northeast QLD appeared to be in fine form. I can also confirm that bearded dragons are adept diggers, which is an effective behavioral adaption to deal with extreme temperatures, both hot and cold. All in all the idea that bearded dragons are threatened by climate change sounds to me like nonsense.


    It would appear that the BOM has yet to homogenise the temperature data from Cunnamulla!

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