Here’s one from the good news but bad news file: The good news is that a Duvaucel’s gecko (Hoplodactylus duvaucelii) has been found on the New Zealand mainland for the first time in nearly 100 years. The bad news is that it was found dead in a mouse trap.
Duvaucels geckos are the largest of our native geckos, and one of the biggest geckos in the world, growing to up to 30cm in total length. They are found on a number of offshore islands off the north-east of the North Island and in Cook Strait, and were thought to be extinct on mainland New Zealand. The last recorded sighting of this species on the mainland was near Thames in the 1920s, but subfossil remains have been found on both the North and South Islands, suggesting it was once widespread across the country.
The dead gecko was found at Maungatautari, in the Waikato. Maungatautari is a 3400 ha nature reserve ringed with a predator-proof fence, making it the largest pest-free area on the mainland. Many rare species have been released into the sanctuary, including kiwi, kaka, takahe and hihi, and reintroductions of many more species are planned. The Duvaucel’s gecko find suggests that there is a remnant nautral population of the species in the sanctuary, which somehow survived the years when the area was overrun with introduced predators. The hunt is now underway for more of the geckos (which will hopefully be found alive).
This discovery shows that you never know what you might find when you protect an area instead of mining it.
More on the discovery on Stuff.
A great new video out on TED.com today has Edith Widder describing some clever applications of bioluminescence in deep sea organisms.
Some 80 to 90 percent of undersea creatures make light — and we know very little about how or why. Bioluminescence expert Edith Widder explores this glowing, sparkling, luminous world, sharing glorious images and insight into the unseen depths (and brights) of the ocean.
Ever wondered what your favourite gene would sound like if it was a melody? Well here’s a website where you can find out.
Basically what it does is take the DNA sequence, convert it to amino acids, and assign each amino acid to a musical note (with some modifications to make it more musical, described here). There is also a complicated way of assigning rhythm.
Gene2music is the brainchild of Rie Takahashi, Jeffrey Miller, and Frank Pettit at UCLA.
A central premise in conservation genetics is that high genetic diversity is good for a species’ continued survival, and low genetic diversity is bad. This seems intuitively obvious (after all, we all know that you shouldn’t marry your cousin) but actually finding examples in nature where we can say for sure that low genetic diversity has contributed to a population’s demise is difficult.
However, the recent decline of tasmanian devil populations due to disease provides an excellent example of the perils of low genetic diversity. Wild devil populations in eastern Tasmania have been decimated in recent years by devil facial tumour disease (DFTD). This nasty disease is a transmissible cancer spread by biting, and causes large tumours to form around the mouth, interferring with feeding and eventually causing death. Kathy Belov’s group at the University of Sydney has been studying the genetic basis of DFTD susceptibility in devils and has found that a lack of variation in immune system genes is responsible for the spread of the cancer in some populations. Read the rest of this entry »
In Biology Letters this week is the report of a new giant monitor lizard discovered in the Phillipines. Varanus bitatawa is 2m long, brightly coloured and has a double penis, and lives high up in the trees on the island of Luzon.
It always amazes me when new species of large vertebrates are discovered in this day and age, when you would think that the majority of the world has been given a thorough going-over, and that 2m long lizards would have been noticed. Actual new discoveries – as in “thats the first time we’ve seen THAT animal”, as opposed to an organism thats been known about for years but only been named as a separate species on the basis of DNA analysis – are pretty rare these days. So I was slightly disappointed to find out that Varanus bitatawa is only a new discovery from a western scientific perspective – Filipino tribal hunters have of course known about it for years.
National geographic has more on the discovery here.
The genome of the zebra finch was published in Nature today and is free to access here. This is the second bird species to have its genome published – the other one being the chicken. The zebra finch is a member of the Order Passeriformes (the songbirds) and is something of a model organism in neurophysiology. Not surprisingly its genome has a number of interesting features associated with song and vocal communication. I hope to have some time to write more about the songbird genome later but in the meantime here’s a summary from Nature:
The genome of the zebra finch — a songbird and a model for the study of vertebrate brain, behaviour and evolution — has been sequenced. Its comparison with the chicken genome, the only other bird genome available, shows that genes with neural function and implicated in cognitive processing of song have been rapidly evolving in the finch lineage. The study also shows that vocal communication engages much of the zebra finch brain transcriptome and identifies a potential integrator of microRNA signals linked to vocal communication.