William M. Briggs

Statistician to the Stars!

Lizards all male climate change club

Nature magazine reports this headline: Condemned to single-sex life by climate change.

They are talking about a species of lizards called tuatara that live “on about 30 small islands in New Zealand?s north.” The disgusting, scaly creatures are in exile on those islands because they have everywhere else been “wiped out by predators.” No word on who or what these predators are or why the predators cannot follow the tuatara to the islands and thus continue their campaign of herpetological genocide.

Anyway, the lizards are about to go extinct and it’s all your fault. It seems that when the weather is hot, more male tuatara lizards are born than female lizards. And we all know what happens when there are more boy than girl lizards. It becomes impossible to get a date and procreate.

This “doomsday prediction”, we are told by researchers, is assured because of (what else?) global warming.

How do the researchers know this? Why, a computer told them so.

Previous computers did not tell them so, which forced the researchers to reprogram them, this time incorporating in their models “physics of heat transfer with terrain data.” Well, that is impressive. The researchers then “simulated climate change and then monitored its effect on specific points across the island.”

What they found was shocking: Rampant maleness, which naturally carries with it the consequence of enforced bachelorhood.

For those of you who are not as computer savvy as I, let me summarize. Researchers programmed a computer to show that when the temperature rises, fewer female lizards are born. They then told the computer that temperatures were in fact rising. The computer then said “fewer female lizards are born.”

The researchers pored over this result and came to the conclusion that “warmer temperatures caused by global warming imply fewer female lizards will be born.” They wrote this in a paper which was duly summarized at Nature. Science in action!

All might not be lost because, the researchers suggest, the lizards might be “translocated” ( = moved) to cooler climes. I just hope that those mysterious predators aren’t in the new translocations.

21 Comments

  1. 10 seconds of googling would have found that the mainland population was wiped out by the introduction of rats in the 19th Century. And there is only one heavily protected sanctuary where they have been re-introduced. If you think the impact of non-native populations (rats, possums (in NZ), rabbits (Australia) etc.) are only of academic concern, you need to do some background reading.

    Models are there only to quantify the effects of underlying assumptions, and in complex situations these are not as simple as A goes up and then so does B. People want to know more – what is the threshold? how does it tie in with larger scale regional climate, how do the microclimates in these islands respond to large scale forcing? It’s not obvious that this paper has the final answer, but sneering at their attempt does you no credit. Presumably you’d be happier with unquantified hand-waves?

  2. Briggs

    July 2, 2008 at 9:54 am

    Aha! Rats! I was kind of hoping it was something more interesting, like Tasmanian Devils or small children.

    Well, what’s to stop the rats from island hopping and chewing up the remaining lizards? It is not that I am uncaring towards lizards or the potential harm from introducing foreign species, but it is doubtful that the researchers were able to quantify in their model the uncertainty of the rats’ future aggressiveness, or even the potential for the lizards to mount a counter attack.

    It is also unlikely that they can approach adequately quantifying how micro- or macro-climates effects lizard reproductive biology over time. People might want to know more, but generating complex computer code to satisfy this need is not responsible.

    So, yes, I would prefer the honesty of an old fashioned, unquantified hand wave, especially when the alternative is unjustified quantification which makes people more sure of themselves than they should be.

  3. Substituting contrived computer models for actual research? Say it isn’t so!

    Yes, I’ve noticed the same tendency in climate-related “research.” It is almost as if this new breed of scientist is too lazy to devise actual experiments, so they are letting their (closely supervised) computers do the research for them.

    Then when they get the results they had predestined themselves to get, they proudly present their findings to an adoring community of circular jerkular fellow echo chamber singers.

  4. It could be laziness, or just more ‘cost-effective’, which would mean less tromping around and camping out on remote islands and therefore more budget left over for conferences at swanky resort hotels.
    Just a guess, but there does almost seem to be an aversion to formulating testable hypothesis where it might me you were wrong about something.

    Copied from comments in another blog:http://solarscience.auditblogs.com/2007/11/20/place-your-bets-for-sc24/#comments

    The Modern Science Method:
    1. Form clique of friends
    2. Announce new ?ground-breaking paper? to the press. Announce ?result? in soundbite form.
    3. Get papers published peer reviewed by friends
    4. Go to United Nations and declare ?the science is settled?
    5. Denigrate other scientists who disagree with you as ?Deniers? and in league with [insert scary corporation here]
    6. Praise other ?independent? scientific papers written by your friends which miraculously support your hypothesis.
    7. Repeat the above two processes so that you and your friends get lions share of grant money while your opponents are starved of funding and attention.
    8. Hide data/methodology so as to prevent replication. Make sure only copy of data is on a floppy disk and never, ever backed up like normal people.
    9. Start weblog.
    10. When cornered, declare that ?science has moved on?

  5. Heh. I worked in a national simulation lab in grad school, from which I learned that in all cases, a computer simulation tends to support whatever the experimenter’s hypothesis may have been.

  6. The computer model is just a starting point. We would need real life observations to verify it.

    The article says that this lizard has evolved and survived for more than 200 million years. It is illogical to suggest that a 4 C hike in average global temperature would wipe it out. What was not included in the article were the uncertainties of each assumption. What do we know about these lizards?

    “Tuataras have the longest incubation cycle of any reptile 12-15 months of incubation time. This is partly due to the egg’s shutting down during the colder months.” http://reptilis.net/rhynchocephalia/sphenodontidae/guntheri.html#Sex

    Warmer temperatures would reduce the incubation cycle shortening the time the eggs are vulnerable to predators.

    Here is the paper referenced in the article:

    http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1559618

    It says, “[t]he thermosensitive period (TSP), where temperature influences gonad morphogenesis, occurs between 0.25 and 0.55 of embryonic development.” This new paper would have to establish that the sensitive period of the embryonic development stage is in the summer (Jan-March). We know that the mating rituals start in January, but when would the eggs reach the quarter point of the embryonic stage? It then is only vulnerable for just over another quarter of the embryonic development stage. How long is the embryonic development stage anyway? These are important questions when assessing the uncertainty.

    The article says, “[t]hey found that based on maximum warming predictions, tuatara, which hatch as males when nest temperature during development moves above 21.5?C, will be incapable of producing females.” Why did the Nature article not mention that there is second pivotal temperature above the 23-24C mark where more females will be produced?

    All this information is needed simply to try to figure out the uncertainty of some of the original assumptions.

    John M Reynolds

  7. Gavin states,

    “Models are there only to quantify the effects of underlying assumptions, and in complex situations these are not as simple as A goes up and then so does B…….It?s not obvious that this paper has the final answer, but sneering at their attempt does you no credit” ”

    And on RC he has recently been claiming that a little showmanship will get the people motivated about climate change, AND sneering at every non-AGW theory you hear. Can’t take what you’re dishing out???

    Tell me, if something is more complex than +A = +B, then why release papers saying +CO2 = +lizard death, or +ice melt, or +hurricane, etc….???? Why aren’t you tearing apart Newsweek for claiming that nothing is natural anymore, and it’s all caused by Global Warming? Nothing more hyperbolic than that!

    My point is, if you know it’s more complex, then don’t church it up as linear. If you’re going to complain about snide remarks towards crap research, then stop doing it on RC. If you do want to continue harping on crap research, then point it consistently, regardless of AGW-ideology lines.

  8. I’m not sure why the fact that one can discover the species of predator by Googling makes it acceptable that the authors failed to identify them with the four letter word “rats”.

    Generally speaking, if a single four letter word like “rats” is sufficient to clarify a large open question in an article, it’s best to include the short word.

    Maybe this doesn’t apply at Nature.

  9. Congratulations Matt on smoking Gavin out.

    Can anyone tell me how difficult it is to determine the sex of a lizard? I assume, Matt, that the population estimates were based on a sound and reported sampling method.

  10. One of the assumptions in this research is that the behaviour of the tuatara remains constant while climate changes. One of the reasons tuatara survived the last 200 million years is because it is not a specialist. That is, it is capable of changing its behaviour in response to environmental change. In this instance, a decrease of average global temperature of ~10 deg C.

    Tuatara is not the only reptile whose offspring’s sex depends on incubation temperature. Presumably, like other reptiles, they can bury their eggs at differing soil depths to vary incubation temperature.

  11. If you want to sneer at Nature you’ll look less foolish if you read up on the basics first – Tuataras are not lizards. (fsecond attempt with out link this time)

  12. andrewt @ #11

    Oddly the World Association of Zoos and Aquariums describes the Tuatara thusly:

    “The Tuatara is a medium-sized lizard with a large head and no tympanum.”

    and the Encyclopedia Britannica describes “lizard” as “any member of the suborder Sauria.”

    And, much to the Git’s amusement, Wikipedia’s illustration on the Sauria page is a Tuatara. šŸ™‚

  13. Wikipedia might also have included a picture of a bird, crocodile or snake in their Sauria piece – do you contend these are lizards PG?. The accompanying text in Wikipedia explains the EB definition of lizard:

    “The term “Sauria” has previously been used as a synonym of Lacertilia, a suborder of Squamata that includes all lizards but excludes snakes.”

  14. As they seem to be on the verge of extinction anyway, why don’t we just round up the last of the little critters, mince them up for burgers and have a barbecue. If there aren’t enough to go around we could add some pandas into the mix.

    Those on the extinct list would get a good send-off, we would get a never-to-be-repeated party and the so-called researchers would have to get proper jobs and stop bothering us with pointless papers.

  15. Magnus Andersson

    July 3, 2008 at 5:30 am

    Gavin: Why is it so important to do this research regarding temperature and alarmistic global warming models? Models where 1 degree C has an unlikely and strong positive feedbacks which are falsified for the most important factors, water vapor and clouds.

    Why not instead look at which problems a little ice age will bring? Lizards has had a perfect warmer climate, say, millions of years ago, but also survived several ice ages.

    The rat-argument implies that there may be problems with all the “environmental travelling”, e.g. to rain forests, Antarctica, and all places in the Arctic region, mainly arranged by environmental organizations. How many species will in this way be killed by global warming alarmism?

    What if too many studies on species (and global warming according to falsified climate models) increases the risk for endangerous species more than any temperature shift does?

  16. andrewt @ #13

    I contend that William/Matt/Briggs’ [delete whichever is inapplicable] use of the term “lizard” is perfectly acceptable in zoological and etymological circles.

    Jennifer Viegas’ Discovery article on the Tuatara’s unique genetics is entitled “Laid-back lizard an evolutionary sprinter”. The paper in Trends in Genetics that inspired her notes that the Tuatara has the fastest evolving genome of any creature we know.

    Yet despite holding the world speed record for evolution, its morphology has remained remarkably constant for 200 million years. The article fails to mention that this is a little embarrassing for ultraDarwinism. šŸ™‚

    Oh yes, the Adelie penguin, also “threatened by global warming” is the runner up in the genomic speedstakes.

  17. Alan Wilkinson

    July 5, 2008 at 9:50 pm

    The most ludicrous part of this ludicrous paper, at least as summarised in The Times, is that the authors expect global temperatures to rise 4 degrees C by 2085.

    Ain’t gonna happen. Must have been listening to Hansen/GISS twisting the temperature record in circles until they can get it to point upwards.

    Invest in coal mines. They’ll be the new oil fields in a decade when CO2 hyper-sensitivity is discredited.

  18. The main sanctuary for the tuataras is an island in Cook Strait. The weather records from the lighthouse on the island do not show any significant warming trend. There have been several smaller colonies of the creatures started on other islands. It is likely that the climate trends there have been similar. The creatures lay their eggs in burrows that they share / take over from nesting sea birds. The incubation / sexing temperature would be more influenced by the season (where the variation is 10?C than the annual average.

    Why do I suspect this is a beatup to get more research funding?

  19. What was the global temp back in the Jurrasic when lizards ruled the earth? Many suspect it was far warmer than now. Yet lizards (or lizard-like creatures) managed to generate males and females at the same time. I assume so, anyway.

    Speaking of fauna extirpating fauna, the strangest place I’ve ever seen is Guam, where the brown tree snake has wiped out the bird life. No tweeting and spider webs everywhere. So it’s not always the rats. Sometimes the herps are to blame.

  20. I live in New Zealand and have been fond of Tuataras for a long time. They are being successfully bred in captivity. They are not in danger of extinction.

    Rats were introduced to NZ by humans only a few hundred years ago.

    The “Depatrment of Conservation” (DOC) is a New Zealand government body which has developed a very effective method of eradicating rats from quite large islands. This was previously thought to be impossible. This means more and more of our islands are becoming predator free. This has allowed a number of new populations of tuatara to be established. Sea bird populations have also benefitted.

    This article seems like a blatant case of using fear of climate change to get a bit more funding.

  21. ?Tassit knowledge gets lost in translation? doesn?t it though Gavin?
    Was this tassit knowledge,like yours, vital or just accademic?
    Now go back and read what you posted at the top.
    Tell me you?re passionate about rats and lizzards.

Leave a Reply

Your email address will not be published.

*

© 2017 William M. Briggs

Theme by Anders NorenUp ↑