Thursday, June 30, 2016

Schleich's new Dunkleosteus model

I have the latest Dunkleosteus model on the market, and it's pretty amazing visually, even if the science causes a bit of head-scratching.
The new model from Schleich boasts multipart construction with an articulated lower jaw and detailed mouth inside and out.  The armor is likewise done in great detail, complete with countless scratches from Dunk-to-Dunk combat: we know the species was cannibalistic, so there was some fighting, although this individual is more heavily scratched than any fossil.
The model is studded end to end with surface details: vertical winkles on the right side of the body and left side of the tail (the fish is shown with the body bending, and the wrinkles match up).
The model is big, over 22 cm long, and studded with either tiny bones (osteoderms) or scales all over. (The animal probably had neither, but it adds a great deal of texture and character to the model).



The amazing new Schleich Dunkleosteus

We don't know what the tail looked like, but the model-makers had to pick something, so they went with a tail with a large fin on the bottom.    Likewise, we know it had to have pectoral fins, and these are large and well-detailed. We don't know if dorsal or caudal fins were large or small. And the line of scutes along the sides (meant to suggest a lateral line, perhaps? If so, they are really overdoing it) are an invention as far as we know. Finally, we don;t know how much of the armor was visible vs being covered with skin/muscle: some scientists opt for a more streamlined Dunk.

A dunk expert, Gavin Hanke of the Royal BC Museum, weighed in on my post of this in FaceBook.  He wrote:  "...the reinforced spine like edges to the fins is fiction,.....all the arthrodires I have seen show tubercles in predictable patterns, sutures, lateral line canals, and straight cracks if present are taphonomic artefacts. I have not seen any papers detailing such scratches in any placoderm species." 


So I agree, the model should be more realistic It remains really cool, and the sculptors did put great effort into giving it more detail than the vinyl Favorite Co. model or the smaller Wild Safari competitors. At $20, it's a little more more expensive than those, but completely worth it. 

The smaller Wild Safari dunk (still cool)



(Thanks to Aurora Rayn for giving me the heads-up the moment this new model was posted for sale and to Gavin Hanke.)


Tuesday, June 28, 2016

Zoology has good news to share, too :)

Sometimes it seems that news related to animal conservation and zoology in general is all or mostly bad, whether concerning the disappearance of  a species (like the Bramble Cay melomys, a  small mammal being called the first victim of climate change) or the continued unbalancing of ecology (e.g., the invasive and voracious lionfish just swam into the Mediterranean, threatening to unleash its appetite on an already-battered ecosystem). 


The invasive lionfish may be beautiful, but has already wreaked havoc in the Caribbean.  Governments are encouraging fishermen to catch it for consumption. (NOAA)


The bad news is serious, and we must face it and digest it as we try to limit of reverse the damage we've done to the planet.  However, there remain points of light and moments of reassurance when we discover or rediscover a precious piece of the natural world.  Every bit of knowledge added to zoology is a step toward conservation, and should be celebrated, even if the creature involved might be dismissed by the general public as small and not very interesting. There was definite celebration this year in Nepal, at least among bird lovers. The red-faced liocichla (Liocichla phoenicea) has been missing for 178 years. A small bird with yellow-green or blue-gray body plumage  set off by bright flashes of color on the head and wings, it was presumed extinct in that country, although it has fairly stable populations in neighboring nations and Indochina. Nepalese ornithologists applauded the bird's first definite appearance in their nation since the 19th century.  
A known animal in a previously unknown location is another kind of discovery.  Consider an eyeless cave fish, the Mexican blindcat, which was just found for the first time in Texas.  The near-transparent 7.5cm fish's appearance so far north raises the possibility of undiscovered caverns connecting underneath the human-imposed border.  (Insert political jokes HERE.) 
A new species of lizard has been added to the world's known reptiles after discovery of two specimens in China. Ptychozoon bannaense‬ has a body not much longer than the just-mentioned cave fish's, but has a stocky build and a camouflage coloration pattern that make it look bigger and tougher than it is.  A dark, elongated new salamander has turned up thanks to a review of specimens from Honduras, Oedipina capitalina lives near the capital of Tegucigalpa (where my oldest daughter was born). Two new frogs hopped into view in India, and another lizard, Liolaemus parthenos (the species consists entirely of parthenogenic females) is reported from Argentina
We find new things about known species, too. Scientists are constantly taking new looks at known species, even well-known species, and coming away with new insights. Take the case of Kenneth Catania of Vanderbilt University, who just discovered that old myths about electric eels leaping out of a pond to stun prey are not myths.  



The electric eel cannot be called beautiful, but can certainly be called dangerous. (NOAA)

A big eel-like fish (not a true eel) whose shock can knock a human unconscious should at least stay in the water, right?  Instead it will shoot its forebody above the surface so the sells on its chin make contact with prey.  
I sense a new SyFy electric eel movie is on the way. That would be a kind of bad news all by itself. But the point is, the news is never all bad. There are still discoveries being made, species being saved, and new knowledge being gained. The future is challenging, but it isn't hopeless. 

(To learn about new species discovered in the mid-20th-to early 21st centuries, I naturally recommend Shadows of Existence: Discoveries and Speculations in Zoology. It's lively, fact-packed, beautifully illustrated, and I need the royalties.  Contact me at mattwriter@earthlink.net or go to https://www.amazon.com/Shadows-Existence-Discoveries-Speculations-Zoology/dp/0888396120.












Friday, June 24, 2016

Bears and hybrids and more bears

There are few animals more interesting than bears. I've written several times before about them, but I can never resist coming back and looking for some new tidbits. 

They are smart: a bear in California learned how to bounce on the roof of a Volkswagen Beetle and pop the doors open.  They are strikingly human-like when de-furred: some Native Americans considered them a brother animal to man. They can be huge: a modern polar bears weighing up to a metric ton are on record, and the biggest brown bears (Ursus arctos) of the Kenai Peninsula and Kamchatka, reach well over half that.  (Mammologist C. Hart Merriam once classified 86 species of brown bears: We now consider them to be one species with just four subspecies). Speaking of grizzlies, everyone who loves them should read Ernest Thomson Seton's Biography of a Grizzly, originally published in 1900: in 1970, it was the basis for a very loose Disney adaptation called King of the Grizzlies.  
A cage-fat male brown (Kodiak)  bear named Goliath, who was born in Alaska and died (in a small concrete-floored cage) in a roadside museum/zoo in New Jersey in 1991, reportedly weighted 900kg, which sounds suspiciously on the high side even for a captive. A bear named Clyde who died in the Dakota Zoo in 1987 was listed at over 900kg and was claimed by the zoo director to have hit an astonishing 1,090kg.  Here in my hometown of Colorado Springs, the Cheyenne Mountain Zoo reported in 1955 the death of a male Kodiak weighing 757kg.   
John "Grizzly" Adams' biggest-ever captured bear, a California grizzly named Samson, was weighed at 685kg.  A Kodiak killed in the wild in 1894 was reportedly weighed in at 751 kg.  Estimated weights of over 700kg have been reported for a bear killed at Cold Bay, Alaska, in 1948 and for a another Alaskan bear killed in 1916. 
The extinct North American short-faced (and long-legged) bear (Arctodus simus) was taller than any known bear - pretty close to horse-height when standing on all fours, and there's a cave in Missouri where an individual left claw marks 4.5m off the floor.  Its  earlier, but much bulkier, South American relative Arctotherium angustidens might have weighed 1,600 kg or more.  Indeed, this animal was probably the biggest mammalian land carnivore of all time: it must have terrified everything in its world.
Some mysteries about bears have been solved. We know now the long-puzzling individual called MacFarlane's bear was a grizzly, not a new species. The astonishing-looking golden moon bears have been confirmed as a real phenomenon, but a variant of a known species, the Asiatic black bear. There's still some fuzziness (if you'll pardon the pun) about classification of the smaller Asian bears, and the gigantic, big-footed solid black oddity known to cryptozoologists as Bergman's bear is not quite ready to be filed away with other Kamchatcan brown bears (U. a. piscator), but there are no definite specimens.
Then there are bears that ain't, as an old hunter might say. In 1998, Reinhold Messner published a book identifying the yeti, or chemo as his Tibetan associates called it,  as a new species, or a subspecies of the brown bear. This bear, the mountaineer alleged,  habitually walks upright (standing up to 2.7m) travels by night and communicates by whistling.  The book, though, includes pictures of quite ordinary-looking brown bears Messner was told were chemos. British geneticist Bryan Sykes took a look at the yeti/bear question by testing DNA from alleged yetis and from bears. After a great deal of hype and confusion, though, it appears he didn't make any discoveries about new bears or about yetis.  
One thing  that is happening in the world of bears isn't a good sign. As climate change allows the brown bear to forage further north but limits the ice cover polar bears use, it's essentially squeezing the two species' ranges closer together.  Sometimes this results in war, sometimes in love. The first grizzly-polar hybrid confirmed in the wild was shot in 2006 and another in 2010. A suspected hybrid killed in May 2016 was identified as an extremely light-colored "blond" grizzly bear. Such grizzly bears have also been spotted in Alaska.  The polar bear is not endangered, but it's getting less healthy as a species, thanks to the attrition caused by habitat loss. 




The paw of a polar bear attests to the animal's size (NOAA)





A hybrid sun bear/Asiatic black bear, meanwhile, has turned up in Cambodia. It's hardly surprising. It's not so much a case of the habitats being compressed, as in North America, but the sheer brutal annihilation of Southeast Asian wildlife   - described heartbreakingly in Sy Montgomery's book Search for the Golden Moon Bear -  means bears of any species may get desperate for mates. 

 (Gary Galbreath, who led the team describing the hybrid, coauthored Moon Bear. I have an admiration for Dr. Galbreath, though we've never met: I don't know how he or other scientists deal with sadness on such a scale while fighting long odds to save species. Cryptozoologists also know Galbreath for his proposed sei whale identification of the famous 1848 Daedalus sea serpent. Also for his 2006 paper arguing the kouprey, the largest land mammal discovered in the 20th century, was a  feral hybrid rather than a new species. He's a prolific guy.) 

So concludes this week's visit with the bears.  There's a lot more to discuss abotu them, and a lot we still don't know. They have a lot to teach us - if we can keep them alive.  

A few bear references:
Day, David. 1990. The Doomsday Book of Animals. New York: Viking Press.
Domico, Terry. 1988. Bears of the World. New York: Facts on File.
Galbreath, Gary, et. al. 2008. "An Apparent Hybrid Bear From Cambodia." Ursus 19:85-86
Goodwin, George. 1946. "Inopinatus the Unexpected," Natural History, November.
Halfpenny, James. 1996. “Tracking the Great Bear: Mystery Bears,”  Bears, Spring.
Montgomery, Sy.  2003.  Search for the Golden Moon Bear.  New York: Simon and Schuster.
Wood, Gerald L. 1983. The Guinness Book of Animal Facts and Feats.  Sterling Publishing Co.
Woolford, Riley. 2007. "White Black Bears and Blond Grizzlies: Alaska Bears Wear Coats of Many Colors," Alaska Fish & Wildlife News, September.  
Discussion thread at http://shaggygod.proboards.com/thread/474/guinness-world-record-kodiak-bears

Sunday, June 19, 2016

Finding Dory and saving the seas

It looks like "Finding Dory" is a whale of a hit.  Great news for a warm, funny family film, not so good for the real fish.  Conservationists fear a repeat of the zoom in demand for clownfish 13 years ago, which basically wiped out some local populations.  Saltwater aquarium owners are being warned that blue tang are hard to keep healthy and are not a hardy species: people are asked to make sure their Dorys are captive-bred.

Danger for the Blue Tang







Regal blue tang (copyright unknown)

Thursday, June 16, 2016

Cryptozoological fiction: Steve Alten's MEG: Nightstalkers

OK, I finished my first read of MEG: Nightstalkers. 


Alten's latest is full of creature action, indeed a little overstuffed, and the chemosynthetic ecosystems presented would have to be orders of magnitude more productive than known examples to support a food chain allowing for giant-predator populations. (I'll give him a pass on the last such ecosystem we visit, though, because he's conjured up some invertebrate predators that may be unrealistic but are among the creepiest, scariest things in all of monster fiction). There is also a science fiction thread that makes sense only if you've read his novel Vostok.  
I always nitpick mistakes in technology in fiction.  I recently worked on whale-tracking technology, and the tech to track a whale 13,000 feet down, or under an ice sheet, in real time (as opposed to using pop-up tags that archive data) is too much to ask: marine tracking devices have very low power, under 1 watt, because otherwise they'd drain the batteries too fast. A character says at one point (correctly) that they can't track a whale in a subterranrean river deep under an ice sheet, then says on p.318 that they can.   
The old characters are all here, of course, and the game of "who will get eaten?" remains suspenseful to the end. Overall, the characterization is a bit below that in Alten's best novels, Sharkman and The Loch
There's kind of an arms race between Alten and Max Hawthorne over who can write the biggest creatures. Hawthorne's latest novel takes a a funny poke at Alten's "puny" Megalodons, and Alten pushes back by making his Liopleurodon not only bigger than Hawthorne's but saying it  surprised scientists because the fossil evidence is for creatures only half as large.  Hawthorne has been arguing that one fossil supports a gigantic pliosaur,  so this could be a dig on Alten's part. I'm not sure whether this is deliberate, but it's a fun connection to make. In general, I have the same criticism of Alten and Hawthorne I always do: even if you set side the implausible circumstances needed for undiscovered survival up the present day, I think the creatures are too big, too smart, and too emotional. But if all you want to do is enjoy the adventure, you can set that aside as being within the purview of a novelist and go with it.  
In sum, this is a crowd-pleaser for Alten (and  Hawthorne) fans: exotic locations, giant predators, lots of blood, and a mix of heroic and stupid characters (who are sometimes the same person) getting in and out of hair's-breadth scrapes. Alten turns his fondness for pop culture and reality TV up to 11, and that's always fun, and my favorite predator of all time, Dunkleosteus, gets a couple of pages. If what you want is a slam-bang, ocean-spanning monster adventure, you'll enjoy diving into this one. 

Sunday, June 12, 2016

Hybrids Among the Whales

(by Matt Bille with help from Dr. Darren Naish and Richard Ellis)
From Shadows of Existence, 2006, Hancock House
Unusual cetaceans are most often thought to be anomalous individuals of a known species or members of an unknown species. In some cases, there is a third alternative: the animal might be a hybrid. There are a surprising number of cases in which different species of cetaceans have interbred, with some striking results.
For example, the skull from a whale killed in Greenland in 1986 or 1987 appears to be evidence of a hybrid between the two known monodonts, the beluga and the narwhal. The skull was spotted in 1990 by Mads P. Heide-Jorgensen of the Greenland Fisheries Research Institute. It was sitting on the roof of a tool shed in the settlement of Kitsissuarsuit.
Hunter Jens Larsen, who killed three identical whales of the type the skull came from, recalled the animals seemed very strange to him. They were a uniform grey color, showing neither the distinctive white of a beluga nor the mottled back of a narwhal. Their tails looked like a narwhal's, which has distinctive fan-shaped flukes with convex trailing edges, but their broad pectoral flippers resembled a beluga’s. While these cetaceans had no horns, analysis of the skull indicated two teeth showed growth patterns resembling the spirals of a narwhal tusk. These teeth may have protruded outside the mouth.
Hybridization is also known to have occurred between the two largest animals on Earth, the blue whale (Balaenoptera musculus) and the fin whale (B. physalus). In a 1998 article in Marine Mammal Science, Martine Berube and Alex Aguilar reported finding five such examples documented in scientific literature. The authors devoted most of the article to a hybrid caught off Spain in 1984. This animal showed features intermediate between the two parents. The whale was four years old, and, at sixty-three feet in length, “anomalously large” for its age. Another instance, described in the Journal of Heredity in 1991, concerned a similar hybrid caught off Iceland in 1986. In the 1986 case, the whale turned out to be a pregnant female. Analysis of the fetus indicated the father was a blue whale. This was the first case in which such a hybrid was proven to be fertile.
These hybrids tend to be dark grey and are usually mistaken for fin whales. Curiously, an author named A. H. Cocks, writing in 1887, stated there were three kinds of giant baleen whales caught off the Norwegian coast. One type appeared intermediate between the blue and fin whales, so much so that Cocks called it the “bastard” and suggested all such animals were hybrids. If this is an accurate deduction, hybridization between these two species has been going on for a long time.
Such a hybrid has figured in the controversy over the continuation of whaling for “scientific research” in Japan. While meat from the minke whales (Balaenoptera acutorostrata) taken in this program is sold legally in Japanese markets, the government has always denied that meat from any protected species is sold or imported. This was disproved when a sample purchased in a Japanese market in 1993 was traced to a specific whale killed off Iceland in 1989. This was possible because the whale involved was so distinctive – a blue/fin hybrid. Such animals are still reported off Iceland. Indeed, a recent hybrid sighting near that island nation is even mentioned in promotions for a whale-watching tour company.
More recently, a new kind of hybrid was reported. A calf spotted near Tahiti in 2000 with its mother, a humpback whale, looked like a hybrid between a humpback and a blue. The calf was abnormally large, yet with pectoral fins that were shorter than normal for its species (the humpback is the only member of its genus, Megaptera, which is named for the whale’s oversized pectoral fins). The calf also displayed the coloration of a blue whale. The parents are not just from different species but different genera. Intergeneric hybrids are freakishly rare and always unexpected. Mammologist Michael Poole speculated that, with blue whales still rare and thinly spread out over the oceans, loneliness may have driven a male blue to seek an unusual mate.
In a Japanese aquarium, a male Risso’s dolphin (Grampus griseus) produced calves with three different bottlenose dolphins (Tursiops truncatus). In 1979, the Whales Research Institute in Tokyo used a photograph of one of these intergeneric calves on a Christmas card. Richard Ellis, who is well-known as both a writer and an artist specializing in cetaceans, wrote, “…when I opened the envelope and saw a shiny grey, short-beaked cetacean, I was struck dumb: I had been studying pictures of these animals for years, and before me was an animal I couldn’t even begin to identify.” In 1981, another aquarium in Japan reported a male false killer whale (Pseudorca crassidens) and a female bottlenose had produced a calf.
While the blue whale-humpback whale mentioned above is the most spectacular example of an intergeneric cross reported in the wild, there have been a few other incidents. Robin Baird wrote in 1998 that a fetus recovered from the corpse of a Dall’s porpoise (Phocoenoides dalli) proved to have an unusual father: a harbor porpoise (Phocoena phocoena). Baird found this particularly intriguing because there are several other reports of unusually pigmented cetaceans with the general size and form of Dall’s porpoises. Although Dall’s porpoises are notably variable in their pigmentation, Baird suggests some of these cases are due to ongoing hybridization with harbor porpoises. Another intergeneric hybrid, this one between the long-beaked dolphin (Delphinus capensis) and the dusky dolphin (Lagenorhynchus obscurus) was nabbed off Peru.
In 2001, an apparent hybrid between a dusky dolphin and a southern right whale dolphin, Lissodeplhis peronii, was photographed among a school of duskies. This very unusual-looking animal was about seven feet long, larger than normal for a dusky. It sported a solid black upper body and was completely white underneath, lacking the intermediate shades normally present on a dusky’s body. On the other hand (or flipper), it had black pectoral fins, whereas the right whale dolphin’s are white, and it had a small triangular dorsal fin. Right whale dolphins have no dorsal fin at all.
Finally, three odd-looking dolphins which washed up on an Irish beach in 1933 were identified by one expert as hybrids between the bottlenosed dolphin and Risso's dolphin. While the match between these two species was proven viable by the incident from captivity described above, not all cetologists accept the hybrid interpretation in this case.
The popular bottlenose seems to be the main instigator of hybridization in captivity. One paper recorded twenty-one incidents in which a Tursiops mated successfully with another species. It’s true there are more bottlenose dolphins in captivity than any other cetacean, but that’s still quite a surprising record. To indulge in a completely illogical, yet human, thought, it's enough to make people wonder what's behind this animal's famous "smile."

SOURCES
Anonymous. 2000. “Loneliness might have prompted whale mis-match,” Australian Broadcasting Company report, September 1.
Baird, Robin, et. al., 1998. “An intergeneric hybrid in the family Phocoenidae,” Abstract, posted to MARMAM@UVM.UVIC.CA mailing list, March 12.
Baird, Robin. 1997. Personal communication, March 28.
Berube, Martine, and Alex Aguilar. 1998. “A New Hybrid Between a Blue Whale, Balaenoptera musculus, and a Fin Whale, B. physalus: Frequency and Implications of Hybridization,” Marine Mammal Science 14(1), January, p.82. Carwardine, Mark. 1995. Whales, Dolphins, and Porpoises. London: Dorling Kindersley.
Ellis, Richard. 2000. Personal communication, March 10.
Ellis, Richard. 1989. Dolphins and Porpoises. New York: Alfred A. Knopf.
Heide-Jorgensen, Mads, and Randall R. Reeves. 1993. “Description of an Anomalous Monodontid Skull From West Greenland: A Possible Hybrid?” Marine Mammal Science 9(3), July, p.258.
MICS Research. No date. “Blue Whale Research Session in Iceland with Richard Sears,” http://www.roqual.com/iceland.htm
Naish, Darren. 2001. Personal communication, September 28.
O’Neill, Michael. 1999. “DNA Breakthrough May Aid Monitoring of Commercial Whaling Ban,” BioBeat, http://www.appliedbiosystems.com/molecularbiology/BioBeat/115-99/whale.html, January 15. Redmond, Ian. 1993. “Beluwhales break out,” BBC Wildlife, November, p.12.
Rice, Dale. 1998. Marine Mammals of the World. Lawrence, KS: The Society for Marine Mammology. Spilliaert, R., et. al. 1991. “Species Hybridization between a Female Blue Whale (Balaenoptera musculus) and a Male Fin Whale (B. physalus): Molecular and Morphological Documentation,” Journal of Heredity 82(4), p.269.

Saturday, June 04, 2016

Book Review: Beyond the Ice Limit

Beyond the Ice Limit
Douglas Preston and Lincoln Child
Grand Central Publishing, 2016, 384pp.


I love the science-heavy thrillers of Douglas Preston and Lincoln Child (although Agent Pendergast is sometimes tiring.)   Beyond the Ice Limit is a very good addition to their canon (I like the co-written books better than either author's solo thrillers).  If it's not quite in the top tier, it's still an excellent thriller. 
Two of the duo's most intriguing characters, engineering genius Eli Glinn and the multi-talented adventurer Gideon Crew, join forces to seek out and destroy the alien organism whose enormous "seed" was planted in the seabed in The Ice Limit. Glinn, who thinks he can predict and engineer anything and any one, not surprisingly thinks this is a task only he is qualified to perform. He outfits a ship with ROVs, submersibles, and a nuclear warhead. The alien organism, though, is far different, far more powerful, and more difficult to deal with than even Glinn envisioned. The gigantic creature they nickname "the Baobab" is in many ways the most interesting, if terrifying, character in the book. The alien is brilliantly imagined, the suspense constant, and the pacing perfect as scientists and crew (no pun intended) race against a threat that is not about to sit there and let itself be nuked. As always with these authors, the technological aspects are superbly described.
I have two nitpicks, one small and one large. The small one is that the warhead they describe would not have come from the very large Soviet-era missile they ascribe it to: it would have been a tactical missile like the SS-21. The big one is an issue that threatens to mess up this whole fictional universe. The all-purpose medicinal root discovered in The Lost Island would have changed the whole world. If everyone got it, people would stop dying, likely leading to ecological catastrophe: if only some people had it, there would be constant violence and wars over access to it. Yet no one in this book ever MENTIONS it except for its effects on Eli and Gideon.If you can overlook that, you'll like everything else about this book: good characters, good gadgets, and nonstop thrills. Great work, gentlemen!

Wednesday, June 01, 2016

EMF, Cell Phones, and Laying Fears to Rest

I'm not a medical researcher. I'm not a doctor. But I'm a parent (both now in college) and I can read. So can we all, but sometimes we read misleading things.

We parents should celebrate when we learn there is no risk in something - when we learn GMOs are safe, vaccines are safe, and there's zero or almost zero chance electromagnetic fields (EMF) have any health effects.  Sometimes we're so concerned for our kids we can't let go once we've heard of a threat. That's human. But you can't worry about everything. You have to prioritize,  So we should stop worrying about GMOs - they are safe, one discredited rat study notwithstanding. Vaccines are safe, one lying "whistleblower" notwithstanding.
Here's the science on GMOs.
Here's the science on the "whistleblower" claim. (Remember, claiming a vaccine conspiracy means you believe doctors and pharmaceutical researchers would rather put their own children at risk rather than break the conspiracy.)

And EMFs are safe, at least in any power level we are likely to encounter in the normal course of life.  The recent cell phone study brought forth panicked, sensationalized headlines about a study that's not even published yet. Blasting rats with cell phone radiation for two years, nine hours a day, may have produced a very slight effect. Or it may have caused nothing but statistical noise. But there's no cause for panic.
This article by Sharon Hill explains it well.
The same thing is true of EMFs in general, such as those produced by power systems, transformers, and transmission towers.  This article by Julie Frantsve-Hawley covers the topic thoroughly.  This post adds to the evidence.

So let's focus on things we need to worry about. Disease and crime and poverty and toxic spills are real things that can threaten our kids.  (Although multiple chemical sensitivity is NOT. Same for amalgam dental fillings.) Let's focus our efforts on the real dangers. We can't worry about everything - and the good news is, we don't have to.