Wednesday, March 14, 2012
Aye-aye lemur 'heats up' its special foraging finger
from BBC nature
By Ella Davies
Madagascar's mysterious aye-aye warms up its extra-long finger when searching for dinner, scientists have found.
The lemur, the world's largest nocturnal primate, taps its specialised middle finger on tree trunks to find nutritious beetle larvae.
Studying thermal images, researchers found that the digit was colder than the others but warmed by up to 6C during foraging.
Scientists suggest that the aye-aye saves energy by keeping the digit cool.
The team from Dartmouth College in New Hampshire, US, wanted to investigate the surface temperature of sensitive structures.
The aye-aye's unusual middle finger has already been found to be super-sensitive to vibrations, so provided the perfect subject for their study.
"It was striking to see how much cooler the third digit was while not in use and how quickly it warmed to [match] the other digits when engaged in an active foraging task," said graduate student Gillian Moritz, who carried out the study under the guidance of her supervisor, Dr Nathaniel Dominy.
Black and white
When not in use, the finger appeared black on thermal images. This indicated a large difference in temperature between it and the white (hot) ears and eyes.
When not in use, the finger appeared black on thermal images. This indicated a large difference in temperature between it and the white (hot) ears and eyes.
But when the animal was looking for food, the finger rose in temperature by up to 6C.
"We think the relatively cooler temperatures of the digit when not in use could be related to its [long, thin] form," said Ms Moritz.
"This form results in a relatively high surface-to-volume ratio [but] such a ratio is bad for retaining heat."
In order to sense the vibrations of beetle larvae through the bark of a tree, the finger is "packed with sensitive nerve endings", the scientist explained.
Because of its specialist sense receptors, using this tapping tool is very costly in terms of energy.
"Like any delicate instrument, it is probably best deactivated when not in use," Ms Moritz told BBC Nature.
"Like any delicate instrument, it is probably best deactivated when not in use," Ms Moritz told BBC Nature.
Kink in the flow
The question of how the lemur controls the heat of a single digit remains unclear.
Ms Moritz suggested two explanations. The first was simply that the blood vessels that supplied the digit could be constricted or dilated.
The question of how the lemur controls the heat of a single digit remains unclear.
Ms Moritz suggested two explanations. The first was simply that the blood vessels that supplied the digit could be constricted or dilated.
The second more unusual possibility, she said, was that the creature might employ temperature control method that was linked to the flexibility of its finger.
Ms Moritz explained: "Because the finger is fragile and vulnerable to injury, it is often extended back and out of the way during locomotion and periods of inactivity," she said.
This extension could cause a "kink" in the artery that supplies warm blood to the digit.
In the same way a bent garden hose supplies less water, the artery could supply less blood, keeping the finger much colder than its fully supplied neighbouring digits.
Aye-ayes are the only primates known to have this strange adaptation.
The species is listed as Near Threatened by the International Union for Conservation of Nature (IUCN), mainly because of threats to its habitat.
But the odd-looking primate also suffers direct persecution. Superstition in Madagascar describes the species as a bad omen. Those that are pointed at by the creature's mysterious finger are said to meet their death.
Is Primatology an Equal-Opportunity Discipline?
food for thought. thanks to Caro D for the link!
my own 2 cents: I think that women generally become more preoccupied with conservation then evolutionary biology when studying endangered species (most primates). This then pulls them towards NGOs and field-based work over academic positions. This is compounded by the fact that most primatologists feel they cannot get positions in zoology/biology departments and must stay in anthropology streams, which means that really don't have the potential to do conservation science if they stay in academia. -MA
Addessi E, Borgi M, Palagi E (2012) Is Primatology an Equal-Opportunity Discipline? PLoS ONE 7(1): e30458. doi:10.1371/journal.pone.0030458
Abstract
The proportion of women occupying academic positions in biological sciences has increased in the past few decades, but women are still under-represented in senior academic ranks compared to their male colleagues. Primatology has been often singled out as a model of “equal-opportunity” discipline because of the common perception that women are more represented in Primatology than in similar fields. But is this indeed true? Here we show that, although in the past 15 years the proportion of female primatologists increased from the 38% of the early 1990s to the 57% of 2008, Primatology is far from being an “equal-opportunity” discipline, and suffers the phenomenon of “glass ceiling” as all the other scientific disciplines examined so far. In fact, even if Primatology does attract more female students than males, at the full professor level male members significantly outnumber females. Moreover, regardless of position, IPS male members publish significantly more than their female colleagues. Furthermore, when analyzing gender difference in scientific productivity in relation to the name order in the publications, it emerged that the scientific achievements of female primatologists (in terms of number and type of publications) do not always match their professional achievements (in terms of academic position). However, the gender difference in the IPS members' number of publications does not correspond to a similar difference in their scientific impact (as measured by their H index), which may indicate that female primatologists' fewer articles are of higher impact than those of their male colleagues.
my own 2 cents: I think that women generally become more preoccupied with conservation then evolutionary biology when studying endangered species (most primates). This then pulls them towards NGOs and field-based work over academic positions. This is compounded by the fact that most primatologists feel they cannot get positions in zoology/biology departments and must stay in anthropology streams, which means that really don't have the potential to do conservation science if they stay in academia. -MA
Addessi E, Borgi M, Palagi E (2012) Is Primatology an Equal-Opportunity Discipline? PLoS ONE 7(1): e30458. doi:10.1371/journal.pone.0030458
Abstract
The proportion of women occupying academic positions in biological sciences has increased in the past few decades, but women are still under-represented in senior academic ranks compared to their male colleagues. Primatology has been often singled out as a model of “equal-opportunity” discipline because of the common perception that women are more represented in Primatology than in similar fields. But is this indeed true? Here we show that, although in the past 15 years the proportion of female primatologists increased from the 38% of the early 1990s to the 57% of 2008, Primatology is far from being an “equal-opportunity” discipline, and suffers the phenomenon of “glass ceiling” as all the other scientific disciplines examined so far. In fact, even if Primatology does attract more female students than males, at the full professor level male members significantly outnumber females. Moreover, regardless of position, IPS male members publish significantly more than their female colleagues. Furthermore, when analyzing gender difference in scientific productivity in relation to the name order in the publications, it emerged that the scientific achievements of female primatologists (in terms of number and type of publications) do not always match their professional achievements (in terms of academic position). However, the gender difference in the IPS members' number of publications does not correspond to a similar difference in their scientific impact (as measured by their H index), which may indicate that female primatologists' fewer articles are of higher impact than those of their male colleagues.
Chimp ‘culture’ paper retracted after authors spot errors, now has home at another journal
thanks to Geraldine F for the link!
from retraction watch
The authors of a 2011 paper claiming that chimp “culture” has more to do with local habitats than with where the chimps live have retracted it after finding mistakes in their work.
Here’s the notice for the paper, “Variation in chimpanzee ‘culture’ is predicted by local ecology, not geography:”
Not surprisingly, the new paper found the opposite of the original results:
Kamilar, we should note, is as critical of others’ work as he is of his own. Late last year, he was a co-author of a Comment in Science alleging flaws in a May 2011 report on whether dinosaurs were nocturnal. Its abstract:
from retraction watch
The authors of a 2011 paper claiming that chimp “culture” has more to do with local habitats than with where the chimps live have retracted it after finding mistakes in their work.
Here’s the notice for the paper, “Variation in chimpanzee ‘culture’ is predicted by local ecology, not geography:”
Shortly after our above paper was published in Biology Letters, we discovered several coding errors in the dataset we analysed. After re-analysing a corrected dataset, we did not find the same results as in our publication. In contrast, we found that no ecological variable was a statistically significant predictor of behavioural variation. Consequently, we do not feel that the main result of our publication is valid and have requested retraction of this manuscript.So how did the errors come to light? Corresponding author Jason Kamilar, formerly of Yale and now at Midwestern University in Glendale, Arizona, tells Retraction Watch:
A colleague contacted me about a week after the paper appeared on Biology Letters’ Early View to request the dataset. We originally used a couple of different methods to code the data and we conducted the analyses about 2 years ago. After looking at the datasets in more detail I noticed several errors that likely was likely due to coding the data from a separately coded dataset instead of the original dataset. I confirmed the problem by re-analyzing the correct dataset and I obtained different results. I contacted the editors of Biology Letters and we agreed that retracting the paper was the best course of action.We wanted to know whether the retraction would have a significant effect on the field.
I think the impact will be quite minor. The retraction occurred less than 2 months after the paper appeared online, and it was never actually published in an issue. In addition, I submitted a new version of the manuscript that contained the correct dataset and analysis, which is now in press in Journal of Human Evolution.
Not surprisingly, the new paper found the opposite of the original results:
…geography, and longitude in particular, was the best predictor of behavioral variation.The authors were also transparent in the new paper, which includes a line noting the retraction:
Our paper also serves as correction to our recently retracted study (Kamilar and Marshack, 2011), which contained several coding errors in the dataset.
Kamilar, we should note, is as critical of others’ work as he is of his own. Late last year, he was a co-author of a Comment in Science alleging flaws in a May 2011 report on whether dinosaurs were nocturnal. Its abstract:
Schmitz and Motani (Reports, 6 May 2011, p. 705) claimed to definitively reconstruct activity patterns of Mesozoic archosaurs using the anatomy of the orbit and scleral ring. However, we find serious flaws in the data, methods, and interpretations of this study. Accordingly, it is not yet possible to reconstruct the activity patterns of most fossil archosaurs with a high degree of confidence.The response from the original paper’s authors wasn’t anything like a retraction; it was more like doubling down:
Hall et al. claim that it is not yet possible to infer the diel activity patterns of fossil archosaurs with high confidence. We demonstrate here that this assertion is founded on unscreened data, untenable assumptions, and inappropriate methods. Our approach follows ecomorphological and phylogenetic principles in a probabilistic framework, resulting in statistically well-supported reconstructions of diel activity patterns in Mesozoic archosaurs.See no evil, hear no evil?
"Orangutan" Song by Bali Rock Band "Navicula"
thanks to caro D for the link and for some background info go to : http://news.mongabay.com/2012/0117-hance_orangutans_video.html
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