Scroll To Top

Wednesday, July 29, 2015

How David Middleton mixes up his lizards at WUWT: hot vs cold climates, eggs vs live birth

Sou | 9:51 AM Go to the first of 18 comments. Add a comment

David Middleton thinks he's hit gold at Australia's ABC (archived here). What he's hit is amber. He should have heeded the warning. David wrote about an article that describes how a team of scientists, led by Dr Emma Sherratt of UNE, looked at lizards fossilised  in amber, from the Caribbean.

Amber means "stop"
(and think)
The ABC article (not the WUWT article, so much!) is about a paper in PNAS, which has this to say:
An unresolved question in ecology is whether the structure of ecological communities can be stable over very long timescales. Here we describe a wealth of new amber fossils for an ancient radiation of Hispaniolan lizards that, until now, has had a very poor fossil record. These fossils provide an important and previously unavailable perspective on an ecologically well-studied group and indicate that anole lizard communities occurring on Hispaniola 20 Mya were made up of the same types of habitat specialists present in this group today. These data indicate that the ecological processes important in extant anole communities have been operative over long periods of time.

This video is from Emma Sherratt, showing her amber-fossilized lizards - beautiful. Something you won't see at WUWT:

From the ABC article:
A community of lizards from the Caribbean, preserved for 20 million years in amber, have been found to be identical to their modern cousins, say researchers.

This suggests the different niches inhabited by the lizards have - incredibly - changed little over the past 20 million-year, report the team, in this week's Proceedings of the National Academy of Sciences.

"These fossils were really surprising because of how much detail they contained, allowing us to see how these lizards would have looked in real life," says the study's lead author Dr Emma Sherratt of the University of New England in Australia.Sherratt says it is "very striking" that the lizards don't seem to have changed at all during this long period, during, over which all the main animal types evolved....

..."Evidence of anolis lizards living unchanged in different niches for 20 million years, indicates these niches have been stable for that period of time," she says.

"That's quite surprising because these lizards have gone to other islands and over to the Florida mainland where they seem to evolve very rapidly. So it's not that they don't have the propensity to change, it's just that the structure of the environment has been stable enough that they haven't needed to change in 20 million years."

Hot vs cold, eggs vs live

Contrast Dr Emma Sherratt saying how evidence from the amber fossils suggests the ecological niches may have been unchanged over millions of years, with what David Middleton wrote:
I guess the Warmists are wrong about climate change endangering lizards……because 20 million years ago, the climate was warmer than today, and the lizards lived through at 3.0°C temperature spike 15 million years ago.

David compares this story about (warm climate) Caribbean anolis lizards to a different article about cold climate Liolaemus lizards. The contrast is striking. Evidence suggests the Caribbean lizards have not changed much. The Liolaemus lizards may be facing extinction with global warming, because they did change much. They changed from laying eggs to giving birth to live young. They adapted to cold climates and probably can't change back (my emphasis):
Researchers, including academics from the University of Exeter, investigated the hypothesis that historical invasions of cold climates by Liolaemus lizards – one of the most diverse groups of vertebrates on earth – have only been possible due to their evolution to viviparity (live birth) from oviparity (laying eggs). Remarkably, once these species evolve viviparity, the process is mostly irreversible and they remain restricted to colder climates.

The lizards that Emma Sherratt was researching were anolis lizards, which lay eggs. The article that David referred to as "wrong" was about how researchers think that cold climate lizards may become extinct because they no longer lay eggs!

Emma Sherratt was saying that the niches inhabited by these particular anolis lizards probably have changed little from what they were twenty million years ago.  David Middleton was arguing that those niches had changed a lot, claiming that those same lizards "lived though at (sic) 3.0°C temperature spike 15 million years ago". His evidence is not from from the Caribbean, but from a chart that some un-named person drew, based on a paper in Science mag from 2001 (Zachos et al). David's diagram is not in the Zachos paper by the way, but I'm not saying it's wrong. I haven't checked. It looks as if it's derived from Figure 2 of the Zachos paper.

That's a twist on the usual approach by deniers. Usually you will find them using a temperature chart from a single location and claiming it is global. This time David is using a chart he says is global and claiming it is local.

From the WUWT comments

There are only two "thoughts" so far (in the two hours since the article went live). The quality makes one wonder how much longer WUWT will last:

tobyglyn has a slightly more rational thought than the other thought: 
July 28, 2015 at 3:47 pm
Ah but those are “special” lizards :)

July 28, 2015 at 3:49 pm
Lizards facing mass extinction…he’s saying they will migrate to the poles and then run out of poles…and go extinct
..right after they start growing bananas and coconuts in Quebec

References and further reading

Emma Sherratt, María del Rosario Castañeda, Russell J. Garwood, D. Luke Mahler, Thomas J. Sanger, Anthony Herrel, Kevin de Queiroz, and Jonathan B. Losos. "Amber fossils demonstrate deep-time stability of Caribbean lizard communities." PNAS July 27, 2015 doi: 10.1073/pnas.1506516112  (sub req'd)

Pincheira‐Donoso, Daniel, Tom Tregenza, Matthew J. Witt, and Dave J. Hodgson. "The evolution of viviparity opens opportunities for lizard radiation but drives it into a climatic cul‐de‐sac." Global Ecology and Biogeography 22, no. 7 (2013): 857-867. DOI: 10.1111/geb.12052 (pdf here)
  • Lizards facing mass extinction - press release from the University of Lincoln (UK)

Zachos, James, Mark Pagani, Lisa Sloan, Ellen Thomas, and Katharina Billups. "Trends, rhythms, and aberrations in global climate 65 Ma to present." Science 292, no. 5517 (2001): 686-693. DOI: 10.1126/science.1059412 (pdf here)

From the HotWhopper archives (David's a denier from way back)


  1. This comment has been removed by the author.

  2. This comment has been removed by the author.

  3. Species, and indeed whole ecosystems, have thermal tolerance ranges (TTR) throughout which they can generally survive with little problem. This can be seen by looking at how species and indeed whole ecosystems actually span significant stretches of latitude and/or altitude before they reach a bioclimatic boundary and give way to other species/ecosystems. Indeed, if species and ecosystems did not have such tolerances life on Earth would have been hugely depauperised by paleohistoric climate change.

    David Middleton completely misses this point.

    And as Sou points out, he also does not demonstrate that there was a “3.0°C temperature spike 15 million years ago” at the location where the lizards occur. Further, the change from the Miocene temperature around 20 million years ago to a temperature approximating that today took several million years at least, which would have allowed for metabolic adaptation (had the lizards actually needed it) even if there was little sign of morphological evolution. And adaptation to a slightly cooler climate over several million years is a completely different issue to adaptation to a warming climate over several hundred years – especially if that warming is twice as big in magnitude as was the cooling...

    Another issue that Middleton misses is that islands don’t have much biodiversity richness compared with larger land areas, and they have much poorer exchanges of species. This means that there may not be as much pressure on species to evolve different phenotypes – they and their ecosystems may be comparatively stable even with temperature change…

    Further still, Anolis lizards are an older taxon than many taxa that are currently extant. They may well have greater adaptability than species that evolved subsequent to the Miocene.

    And Middleton misses the fact that reptilian poikilothermal metabolism is not comparable to endothermal metabolism, or floral metabolism, or...

    I could go on, but his nonsense is such that I would probably waste a whole day finding ever more problems with it.

  4. Middleton is just another conspiracy theorist. From his blog.

    "I also frequently use the word “Enviromarxism” or “Enviromarxist.” Enviromarxists are those politicians and scientists who are threatening to take away our freedom and prosperity in order to protect the environment of the Earth from the ravages of capitalism. I believe that the root of Enviromarxism is school of thought known as Steady State Economics (AKA sustainable development). Al Gore is the poster child of Enviromarxism. "

    His conspiracy theories extend to the science.

    "[climate models] are programmed with very high sensitivities to CO2. Then they are paramaterized (fudged) with assumptions about albedo effects of past anthropogenic aerosol emissions in order to retrocast past temperature changes. The climate models almost totally fail to incorporate cloud albedo effects and natural climate oscillations."

    1. So he's opposed to the idea of steady state economics? He needs to learn some thermodynamics.

      Or to watch China for another decade or so... A 7% pa growth rate results in a doubling every ten years, and China can't double too many times before it's bigger than the planet's capacity to supply raw materials. It's going to be a salient lesson for the world in the unsustainability of any growth-based paradigm...

      That quote from him is typical of the assertion-based ranting of a paranoid nutcase. It's also completely untrue.

    2. I'm guessing that David's gaffe in missing the difference in survivability versus extinction based on oviparity versus viviparity is an example of ereptile dysfunction.

    3. Well, *I* thought it was funny!

    4. Technically China just saw that happen for the first time; they've just countered a run on their marker and saw a 7% drop across their entire economy. When I was there in 2000, they were sustaining 8% growth, but it's important to realize that Chinese indicators of growth were pegged to construction...and there's a lot of empty buildings in the middle of nowhere in China.

  5. I lost it when I figured out the guy hasn't even the minimal wit to realise that there is no equivalnency between slow climate change due to natural variability and rapid climate change due to human stupidity, greed and sloth.

    As far as I can see, the historical template for the impact of rapid climate change just might be found in the mass extinctions at the boundaries of some geological eras. That's not exactly comforting.

    1. Cut him some slack Millicent, if he were not loud, confident and wrong his membership of the Denialerati would be terminated.

    2. Well, today my bile is reserved for an American dentist who thinks that lions deserve to be shot if they neglect to wear a tracking collar, but who shoots them even if they do.

    3. Lured out of the National Park with bait. Shot with a crossbow, injuring the lion. They did not manage to kill the injured lion for several hours. Mindless and barbaric.

      Is that what an intrepid hunter looks like?

      (Sorry, off topic).

  6. So he is saying the globe is warming then? If I relied on WUWT for science I'd be very confused by now.

    As an aside, look for this paper to be quote- mined by creationists who will say evolution tells us species evolve but this 20 mya lizard is identical to modern day lizards. Therefore, evolution is disproven, each according to its kind, scientists are blinded, etc.

    1. That only works if they think the world is more than 6,000 years old. But maybe like climate science deniers they can espouse contradictory beliefs as long as it supports their position.

  7. Sou wrote:

    His evidence is not from from the Caribbean, but from a chart that some un-named person drew, based on a paper in Science mag from 2001 (Zachos et al). David's diagram is not in the Zachos paper by the way, but I'm not saying it's wrong. I haven't checked. It looks as if it's derived from Figure 2 of the Zachos paper.

    That is the iconic 'Zachos Curve' with various text added on by someone else. It's encouraging to see contrarians taking the trouble to label the PETM, fine example of a GHG-forced hyperthermal that it is.

  8. Bananas? It's good to see Latitude (WUWT comment) is keeping up with things.

    ...right after they start growing bananas and coconuts in Quebec

    It won't be long now if les Québecois are not doing it already.

    Toronto is a bit south and has the lake but it's coming. Today Toronto, tomorrow Montreal. Coconuts may be pushing it, I will admit.

    1. The swallow may fly south with the sun or the house martin or the plover may seek warmer climes in winter, yet these are not strangers to our land.

    2. Wondering how long it would be for an MP reference to show up. Mention a coconut, and a swallow or strand of creeper aren't far behind. :-)


Instead of commenting as "Anonymous", please comment using "Name/URL" and your name, initials or pseudonym or whatever. You can leave the "URL" box blank. This isn't mandatory. You can also sign in using your Google ID, Wordpress ID etc as indicated. NOTE: Some Wordpress users are having trouble signing in. If that's you, try signing in using Name/URL or OpenID. Details here.

Click here to read the HotWhopper comment policy.