All posts by John Upton

Was Azaria Chamberlain killed by a native or invasive dog?

By John Upton

Australia’s legal system exonerated Lindy Chamberlain of infanticide this week, again, 32 years after a dingo ran off with her baby. A basis of the prosecution was always the notion that dingoes don’t eat babies. Ergo, prosecutors argued, the mother’s nightmare story was fabricated to cover up her own hideous deed while camping at Uluru.

A dingo at Fraser Island, Queensland, where a four-year old girl was attacked in 2007, helping confirm that dingoes are capable of attacking kids. Flickr: ogwen

Perhaps Chamberlain’s legal nightmare could have been avoided if the powers that be had listened more closely to the Pitjantjatjara people. The traditional stewards of the land where two-month old Azaria was hunted down know dingoes well. They reportedly never doubted that a dingo was capable of such ferocity. Similar attacks since have shown they were right.

The seclusive canines remain a mystery to most people. Scientists cannot even agree on whether the predators should be considered a native species in Australia. That’s because they were introduced several thousand years ago by seafarers sweeping south through Asia.

Those who argue that dingoes are a native species point out that they have struck an ecological balance with the environment.

University of New South Wales researchers set up a test they thought would reveal whether dingoes should be considered native. They monitored the activity of rabbit-like bandicoots in suburban backyards, some of which were home to pet dogs and some of which were not. Because the nocturnal bandicoots avoided yards that contained dogs during the day, they concluded that the creatures have evolved to instinctively identify the threat posed by dogs through thousands of years of dingo interactions. That suggests to them that dingoes have become a native species.

“The logical criterion for determining native status of a long-term alien species must be once its native enemies are no longer naïve,” the scientists, Alexandra Carthey and Peter Banks, wrote in a January paper published in the journal PLoS ONE. “Our study suggests that these bandicoots may no longer be naïve towards dogs.”

On the other hand, the foreign and invasive nature of the species in Australia is also clear.

When dingoes arrived, they did what invasive predators do best: They chewed through the wildlife and condemned native species to extinction. Their arrival coincided with the extirpation from mainland Australia of the thylacine, a dog-like predator that’s better known as the Tasmanian Tiger. The species survived in Tasmania, an island that remained inaccessible to the dingoes, until the 20th century when the last sad specimen died in a zoo.

Thylacines were Australia’s largest predators until the dingoes arrived. Recent research by scientists at the University of New South Wales and the University of Sydney revealed that the female thylacines of mainland Australia were considerably smaller than the dingos, making them vulnerable to direct predation by the continent crashers.

The dueling species also differed in a way that highlights dingoes’ alienness. Like almost all other native Australian mammals, thylacines were marsupials. (The other native Australian mammals are monotremes — egg-laying echidnas and platypuses.) Marsupials give birth shortly after conception and rear their young on a teat in a pouch. Dingoes, on the other hand, are placental mammals. If dingoes are to be considered a native species, then they are the continent’s only native placental mammal.

Dingoes can be found nowhere in the world other than in Australia. They have evolved into a distinct subspecies of the grey wolf, although that distinction is blurred by interbreeding with pet and feral dogs brought by more recent European settlement.

So if dingoes aren’t native to Australia, then they can be considered native to nowhere. They are either a native Australian species or a homeless wolf on a milleniums-long walkabout.

Either of which sounds like an appropriate description to me.

Uluru, a famous sandstone rock in the Northern Territory where baby Azaria was snatched in 1980 / Flickr: LKEM

Algae stole gene to unlock ice

By John Upton

Polar bears are spectacular inhabitants of sea ice, which is an inhospitable habitat that grows and retreats around the poles with the seasons. But something else lives on the harsh terrain that gets much less attention: Algae.

Algae combines ocean nutrients with energy from the sun to provide whales and other herbivores with a critical source of food, particularly in the early spring.

But how did algae come to survive such challenging conditions? Scientists looking for an answer to this question discovered that some evolutionary larceny was necessary before algae could move into the icy digs.

Effect of algal ice-binding proteins on ice / PLoS ONE

Ice-dwelling algae has a special tool that allows it to live in the uninviting climate. These algae ooze gelatinous ice-binding proteins known as extracellular polymeric substances. The proteins manipulate the salt content and pore structure of the ice as it grows around the algal bloom, making the teeth-chattering microclimate all the more accommodating.

Scientists analyzed the ice-binding proteins produced by three species of sea ice-dwelling algae and reported last month in the journal PLoS ONE that the structure of the proteins was “completely incongruent” with the evolution of algae. That strongly suggested that the genes for producing the proteins came from somewhere else.

Species can hijack genes from other wildlife through a number of processes that scientists call horizontal or lateral gene transfer. Viruses are sometimes involved, but not always.

The ice-binding proteins closely resembled proteins produced by bacteria, leading the researchers to conclude that the algae initially stole the gene from bacterial neighbors.

The scientists sampled similar proteins produced by bacterium at the bottom layer of Antarctic sea ice and discovered that nearly half of its amino acids matched those of the special proteins produced by nearby algae.

“Our results strongly suggest that the [ice-binding protein] genes of sea ice diatoms were acquired from bacteria, possibly in separate events,” concluded the researchers. “The acquisition of these genes was an essential factor in allowing the diatoms to expand their range to polar sea ice.”

Sea ice and some icebergs off eastern Greenland / NASA

Fungus thriving, worms waning, after BP oil spill

By John Upton

Fungus has a remarkable ability to thrive when the environment is stressed, allowing it to prey upon animals and plants when those forms of life are weakened. When the Permian period ended with a climate-changing bang 250 years ago, courtesy of volcanoes or perhaps a meteorite, soil fungus overwhelmed the world’s forests. Fungus diseases today are wiping out hundreds of species of frogs and millions of bats, not to mention entire forests.

New research shows that this mysterious kingdom of life is also thriving in the wake of the Deepwater Horizon oil spill.

Scientists studied microscopic life in polluted shoreline sands around Alabama. They compared their findings to the results of surveys taken before the spill and found a sharp reduction in the number and diversity of microscopic animals, replaced by a spike in fungus.

“Our data suggest considerable (hidden) initial impacts across Gulf beaches may be ongoing,” the researchers report in a June 6 paper in the journal PLoS ONE, “despite the disappearance of visible surface oil in the region.”

Tiny sediment-faring worms known as nematodes were heavily affected. Scores of different types of nematodes used to make their homes along the gulf’s floor and it shorelines. But the researchers discovered that these benthic communities are now hospitable for just a handful of nematode species, mostly scavengers and predators.

The fungus that has taken over the oily sand is dominated by species that have a knack for breaking down hydrocarbons. Fungus is the world’s great decomposer and perhaps things will return to normal after the gulf’s new microscopic rulers have converted BP’s disgusting mess into something a little more palatable for the displaced members of the animal kingdom.

Research results

Cross River gorillas caught on video

By John Upton

There are two species of gorillas — Eastern and Western, both of which live exclusively in Africa. Cross River gorillas are an extremely rare subspecies of the Western gorilla. Just 250 of the great apes are believed to live today.

In a world first, using a camera hidden in a tree, conservationists working in Cameroon’s Kagwene Gorilla Sanctuary shot video of eight of them traipsing down a jungle trail.

Wait or scroll through to the 38-second mark to watch one beat his chest and charge past the hidden camera in an apparent show of aggression and domination.