Pretty much everyone who has seen this today shakes their head and wonders. I’m wondering too. First, the story which is being serially regurgitated without any thought in media outlets world wide:
Please read this excepted text from the story carefully:
In what is being hailed as the world’s first evidence of inter-species breeding among sharks, a team of marine researchers at the University of Queensland have identified 57 hybrid sharks in waters off Australia‘s east coast.
…
Ovenden speculated that the two species began mating in response to environmental change, as the hybrid blacktips are able to travel further south to cooler waters than the Australian blacktips. The team is looking into climate change and human fishing, among other potential triggers.
Pretty clear with the headline, right? There’s more examples of this, such as this one from the Business Insider which takes the cake:
Now, read the actual press release from the University of Queensland this story was based on:
World-first discovery of hybrid sharks off Australia’s east coast
A group of leading marine scientists has discovered that sharks on Australia’s east coast display a mysterious tendency to interbreed, challenging several accepted scientific theories regarding shark behaviour.
In a joint-UQ research project, scientists have discovered widespread hybridisation in the wild between two shark species commonly caught in Australia’s east coast shark fisheries.
The Australian black tip shark (Carcharhinus tilstoni) and the common black tip shark (C. limbatus) have overlapping distributions along the northern and eastern Australian coastline.
Using both genetic testing and body measurements, 57 hybrid animals were identified from five locations, spanning 2000km from northern NSW to far northern Queensland. Although closely related, the two species grow to different maximum sizes and are genetically distinct.
Dr Jennifer Ovenden, an expert in genetics of fisheries species and a member of the scientific team said this was the first discovery of sharks hybridising and it flagged a warning that other closely related shark and ray species around the world may be doing the same thing.
“Wild hybrids are usually hard to find, so detecting hybrids and their offspring is extraordinary,” Dr Ovenden said.
“To find 57 hybrids along 2000km of coastline is unprecedented.
“Hybridisation could enable the sharks to adapt to environmental change as the smaller Australian black tip currently favours tropical waters in the north.
“While the larger common black tip is more abundant in sub-tropical and temperate waters along the south-eastern Australian coastline.”
Scientists from The University of Queensland, James Cook University’s Fishing and Fisheries Research Centre, the Queensland Department of Employment, Economic Development and Innovation and the New South Wales Department of Primary Industries are now investigating the full extent of the hybrid zone and are attempting to measure hybrid fitness.
The research, co-funded by the Fisheries Research and Development Corporation, identified a mismatch between species identification using mitochondrial DNA sequence and species identification using morphological characters (length at sexual maturity, length at birth and number of vertebrae).
A nuclear DNA marker (inherited from both parents) was sequenced to confirm the hybrid status.
Dr Colin Simpfendorfer from James Cook University’s Fishing and Fisheries Research Centre said black tip sharks were one of the most studied species in tropical Australia.
“The results of this research show that we still have a lot to learn about these important ocean predators,” he said.
Media: Dr Jess Morgan on 0419 676 977.
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Important point: the press release DOES NOT contain the words “global warming” nor “climate change”.
I suspect this was the trigger for the reporter jumping the shark:
“Hybridisation could enable the sharks to adapt to environmental change as the smaller Australian black tip currently favours tropical waters in the north.
“While the larger common black tip is more abundant in sub-tropical and temperate waters along the south-eastern Australian coastline.”
So “environmental change” gets morphed into a “global warming” headline, when clearly, environmental change could be any number of things; pollution, changes in food supply, overfishing, competition, any of these (and others we don’t know about) could be factors…but “global warming” is automatically looked upon as the culprit. WUWT?
So, lets look at temperature. I asked Bob Tisdale to supply some sea temperature maps and graphs for the area. First the current available SST for Australia:
So much for the idea that the water is cooler to the southeast, and least in November. The waters of the south appear to be warming faster according to this anomaly map.
Here’s the last thirty years of sea surface temperatures from the area:
Less discerning reporters would immediately go A-Ha! The smoking gun, sea surface temperatures went up. Yes they did, and the trend is 0.135 °C/decade, and the trend line suggests Australian coastal sea temperature has increased by 0.45°C over thirty years.
But, in the last ten years (denoted by the span of the blue line) the temperatures have been pretty much flat.
Consider these points then:
1. Would you believe that one of the oldest creatures on Earth, which have managed to survive 500 million years over all sorts of temperature global temperature swings far greater, is sensitive to SST changes of 0.15 degree per decade enough to go on a panic breeding frenzy to save itself?
2. Since these “hybrid” sharks are a recent observation, it stands to reason they didn’t exist 20 years ago, maybe even 10 years ago. In this paper, the maximum lifespan of the Australian black tip shark (Carcharhinus tilstoni) is given:
The greatest recorded ages for C. tilstoni were 12 years for females and 8 years for males…
Davenport, S.; Stevens, J.D. (1988). “Age and growth of two commercially imported sharks (Carcharhinus tilstoni and C. sorrah) from Northern Australia”. Australian Journal of Marine and Freshwater Research 39 (4): 417–433.
So clearly, this new hybrid is a recent decadal scale development, and the last ten years of temperature in the area have been essentially flat. Connecting this with “global warming” doesn’t wash.
3. Ok, back to the “speculation” part of the headline:
Ovenden speculated that the two species began mating in response to environmental change, as the hybrid blacktips are able to travel further south to cooler waters than the Australian blacktips. The team is looking into climate change and human fishing, among other potential triggers.
It seems the Blacktip Shark isn’t confined in range at all, as this 2010 paper shows (bolding mine):
Genetic data show that Carcharhinus tilstoni is not confined to the tropics, highlighting the importance of a multifaceted approach to species identification
Boomer, J.J., Peddemors, V. and Stow, A.J., 2010. Genetic data show that Carcharhinus tilstoni is not confined to the tropics, highlighting the importance of a multifaceted approach to species identification. Journal of Fish Biology, 77:1165–1172.
Summary
Sharks are prone to human-induced impacts, including fishing, habitat destruction and pollution. Therefore, effective conservation and management requires knowledge of species distributions. Despite the size and notoriety of sharks, distributions of some species remain uncertain due to limited opportunities for observation or difficulties with species identification.
One of the most difficult groups of sharks to identify correctly is the ‘blacktip sharks’. This group of whaler sharks are harvested in substantial numbers along the Australian east coast, including NSW, yet little is known of their distribution and resultant potential portion of the commercial shark catch.
The NSW Shark Meshing Program (SMP) research has collected genetic samples from most sharks caught for many years. Analysis of these samples to determine proportions of each species caught in the shark nets yielded the surprising discovery that the tropical Australian blacktip shark (Carcharhinus tilstoni) was regularly represented. Approximately one-third of the ‘blacktip sharks’ previously assigned to the common blacktip (C. limbatus) were identified as Australian blacktip sharks. This discovery extends the range of this tropical species over 1000km southwards into temperate waters off Sydney.
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Wikipedia even has this helpful map of the range of Carcharhinus tilsoni
Nevertheless, as we know (because the Liberals told us so) thousands upon thousands upon thousands of scientists disagree with you Anthony. Therefore – just to be on the safe side – we should be very scared of this, ahem, story, and sacrifice billions of dollars to the Kyoto Gods.
I don’t really need to add a “/sarc” do I?
“Since these “hybrid” sharks are a recent observation, it stands to reason they didn’t exist 20 years ago, maybe even 10 years ago.”
True that they are a recent observation, but perhaps it’s only because they started looking for this recently. Interbreeding among closely related species is quite common.
I suspect that this has been going on for quite a long time. Our tendency for hubris explains why we think it “just happened recently.”
Isn’t shark interbreeding more a function of the avaialbility of breeding mates rather than evidence of CAGW? Perhaps interbreeding is what sharks do when their populations are reduced.
Of course, I forgot, everything is due to CAGW. Sorry , how could I have been so foolish.
“The results of this research show that we still have a lot to learn about these important ocean predators,” he said.
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I’ve never heard of a study concluding that before.
And shouldn’t it be shark “jumps the Fonz” in this case?
I love the whopper analogy Anthony ha ha ha! Media ‘jumping the shark’ for sure! Hysterical.
They seemed to have missed the angle which suggests that presence of hybrids means that they’re not actually derived from distinct species. Distinct species are unable to reproduce with each other and produce ongoing bloodlines (think horse + donkey = mule).
The researchers got caught in an ‘oops’ moment and now have to say ‘gee, I guess length, fin color and number of vertebrate aren’t a sufficient basis to define a species’.
….sounds like a taxonomy problem
Whatever you do don’t tell the media about the mule…..
Climate change causes evolution !!
WOW !!!
Do sharks practice safe sex? Is there a shark body shop some where in the area?
So it is unusual for opportunism to occur in procreation, of course it could be just poor eyesight.
My interpretation of the recency of inter-species breeding is that it probably has been just as common in the past, but between no one looking for it, and the changes in the technology of DNA testing, that it has only been noticed recently. These 2 sharks are closely related and it may be that in the areas where they both live, they have always at least slightly hybridized. If the hybrids are not fertile, then the population of hybrids will not increase like a normal population–there will just be a few of these anomalies around.
PS But the global warming thing is just BS, as noted so clearly!
the world’s first evidence of inter-species breeding among sharks
If successful “inter-species breeding” is well known among non-sharks, what’s the big deal here?
the two species…are genetically distinct.
Almost every human being is “genetically distinct” from every other one. So what? But, then again, we also have ~77% the same genes as Fruit Flies, so that kind of interbreeding would really be a “first”.
“Hybridisation could enable the sharks to adapt to environmental change as the smaller Australian black tip currently favours tropical waters in the north.
“While the larger common black tip is more abundant in sub-tropical and temperate waters along the south-eastern Australian coastline.”
Therefore, possibly helping both kinds to adapt to possibly slightly different niches? My my, isn’t it amazing how “hybridization” works in the course of life’s continuous evolutionary attempts to “adapt to environmental change“, or doesn’t – a more “successful” outcome perhaps being in relation to a changed or expanded “ecological niche” for whatever reason?
Scientists….are attempting to measure hybrid fitness.
So, now, instead of leaving the hybrids alone with Nature, finding out more about what’s already known about Black Tip sharks like Anthony did, thinking about other possible factors producing this “first” in that geographical area, and also simply looking at catches over a period of some years later, the “group of leading marine scientists” are probably going to “help” the hybrids by capturing some of them, doing “scientific” tests under some kind of anesthesia, then probably finish up by putting radio transmitter nose or lip rings in certain lucky individuals, after the manner of “scientists” banding Penguin flippers, to see how they fare?
Patrick Davis says:
January 4, 2012 at 12:46 am
“…Well, anyone who knows the slightest thing about DNA would know that would not be possible without help from a geneticist. Now, I KNOW there is somthing [sic] called inter-species CLONING.”
Ummm….not exactly. In many closely related species, especially those with overlapping ranges, hybridization happens occasionally. As a group, the southern (US) pines (loblolly, shortleaf, slash, longleaf, e.g.) are one good example.
While not considered to be a primary cause, occasional hybridization between recognized species, is a factor in long term speciation.
Cross one of these with a Harrop and you will get a shark that sells Harrop Whirligigs™ and posts mindless babble in the WSJ.
“2. Since these “hybrid” sharks are a recent observation, it stands to reason they didn’t exist 20 years ago, maybe even 10 years ago.”
No, sorry, it only stands to reason that such hybrids have not been observed 10 or 20 years ago.
It does not mean there weren’t any hybrids.
Dr Ovenden says they are difficult to observe in the wild, and they are certainly more difficult to observe in the wild if there’s no funding for such observations! The advances in research technologies like in DNA analysis during the last years probably also played a role here.
Hybrids are of great interest to biologists, and have been studied for some time, see here:
http://en.wikipedia.org/wiki/Hybrid_zone
Unlike Mytilus, the example given in the wiki article, sharks are not sitting around on rocky shores, so establishing a hybrid zone is of course enormously difficult, but it doesn’t mean it doesn’t exist.
This find is hugely interesting, especially when shorn of the usual climate hype by the MSM.
I chuckled at Delingpole’s take, but you win this one. Thanks for the thorough research and analysis! (I failed to find the original release with my quick search after seeing the story regurgitated on Fox.)
I found the following statement particularly informative regarding range limits due to climate and the potential impetuous of warming mattering to these critters mating habits: “…have overlapping distributions along the northern and eastern Australian coastline.” It seems that both already like the climate. Thus, not a justification for interbreeding. I suspect the simple instinct to mate and hormones (however they apply to sharks).
I also note the emphasis on similarity between these two species. It would seem that before DNA testing was common, this hybrid would have necessarily gone unnoticed. It seems unlikely that it is a new phenomenon, we can simply detect it now.
The headlines are the result of man bear pig hybydization.
Mr. Watts,
I am delighted that you debunked this story. It caught my eye and I was betting it was yet one more example of the mass insanity that is now rampant. You’ve confirmed my suspicion.
Interesting detail about the Australian black tip and the common blacktip , they are physically identical except for the number of vertebrae , 174–182 vertebrae in the Australian BT and 182–203 in the common BT so as fishermen rarely count the vertebrae or check the genetic markers of their catch , Australians may well have been dining on hybrid blacktip flake since European settlement and no one would know . I don`t know how the Aborigines at the time were at shark hunting/fishing but given their admirable proficiency at turning anything else that hops , crawls, swims or paddles into a feed there exists the possibility that Australians may have been eating hybrid shark from BEFORE european settlement .
Oh oh, it’s beginning to look like “hybridization” as a result of “environmental change” is gearing up the Sharks worldwide to be able to take out the last of the Polar Bears by 2100. Nat Geo has yet to weigh in regarding the catastrophic effect on the Big Cats as well, but since we already know it “could” happen, that’s all we need to know – pending only a critical grant for a NAS related “study”.
Based on the ‘jump-the-shark-headlines’, I have to wonder why have I never seen:
“Inter Racial Marriages – Proof of Global Warming”
From a historical perspective: Anthropologists have noted that when societies tend to expand allowing people to intermingle more with other societies – thus more potential inter-race children, the planet has been warmer. Conversely, when societies tend to pull back and keep to themselves with people intermingling less – thus less potential inter-race children, the planet has been colder.
Similar to CO2, inter-race children is a driving force on the global climate. This can most easily be seen due to the ease of travel over the recent past. With the speed of inter-continental travel, the possibility of inter-racial children have been more prevalent and was rising until the early 2000’s, since that time world travel has been slightly muted, thus there has been less opportunity for inter-race children, and you guessed it… the temperature has been relatively steady or somewhat falling during that same time period.
While it appears that it can’t get any more simpler than that for proof that inter-race mating causes global warming, the author of the study notes that we shouldn’t jump to any conclusions quite yet and that additional funding and studies are needed to help quantify the impact on the planet in regards to global climate change.
Can I has grant to do proper study now?
Are midgets and basketball players different species?
Unless the researchers can show that the hybrids are sterile, or have some other similar hybrid trait, I think the notion that the mating sharks are separate species needs to be rethought.
I was curious about this when I saw it yesterday, so I did some reading about the species in question. They are morphologically indistinguishable except through forensic examination of their precaudal vertebrae, with the Australian Blacktip (Carcharinus tilstoni) having 84-91 and the Common Blacktip (C. limbatus) having 94-102. Since their ranges overlap considerably, I can’t really see how anyone is surprised that there is some interbreeding between the populations.
I also ran across a paper from September 2011. It describes a new field species assay test that is fast and inexpensive compared to full mtDNA testing. It claims to have been 100% accurate when used with 160 DNA test samples. If this was the method used to perform the study that discovered the hybrids, I would suggest that the species assay might not be as accurate as it appeared during the validation process.
Either way, the mainstream media certainly jumped the shark on this one.
Bit off-topic, but can anyone remember the postings by Tamino, where he performed some stats on the global temperature to indicate that it wasn’t really diverging from the models, but was still within the error bands? In those posts he also gave a divergence at which he said that you could consider those models broken.
This was several years ago now, and I wanted to check how far down the line we had gone. But I can’t find the reference. Can anyone help me with this?