Science News Digest - 29 October 2012
In the news this week... scientists in California tell the story of their talking whale, fossils discovered in Canada lead to new theories about the origin of feathers, how crowdsourcing could save the ash tree, and finally... why ovulation makes women more critical of their unattractive partners.
Who’s a pretty whale?
It’s a long-recognised trick for many species of pet parrot, and researchers at the National Marine Mammal Foundation in California have now revealed that they once observed a beluga whale, with the ability to mimic human speech.
There had long been rumour and mystery surrounding the whale and dolphin enclosure, where staff reported hearing disembodied voices. The truth finally emerged however, when a diver surfaced from the pen and asked colleagues why they had told him to exit the tank. No such command had been issued, and the researchers finally realised where the voices were coming from.
The culprit was a nine-year-old beluga whale named NOC. Although there have been anecdotal reports of whales making human-like sounds, recordings of the the so-called “canaries of the sea” displaying this behaviour, had never before been captured.
The researchers started to record the sounds, and discovered many surprising features of NOC’s outbursts. Firstly, they were very different to the normal noises whales made. The frequencies within the noises were spread out into “harmonics” – something very unlike normal whale noises, and much more like human sounds.
The pauses between vocal bursts were also reminiscent of human speech, and were pitched several octaves lower than is usual for whales. The Telegraph explains how researchers firmly believe that the fact that NOC had deviated so much from his usual vocal patterns (despite the fact that a whale’s vocal mechanism centres around the nasal tract, rather than the larynx) is a clear demonstration that he was trying to mimic humans. Some went as far as to suggest that NOC may be trying to make contact with humans.
The speech began after spending seven years in close contact with the researchers at the centre, although gradually declined, and stopped by the time NOC reached adulthood. According to researchers, vocal mimicry is more common in young animals, as the mechanisms they use to make sounds are more flexible.
New fossil discovery suggests wings developed to woo
A new fossil study suggests that the earliest wing-like structures and feathers may in fact have evolved for the purpose of mating, rather than for flight or keeping warm.
Modern birds inherit wings and feather from dinosaur ancestor, such as the feathered species Ornithomimus edmontonicus. Experts have now examined three newly discovered fossils of this species, one young and two adult dinosaurs, from a 75 million-year-old rock formation in Canada. These fossils mark the first discovery of ornithomimid specimens preserved with feathers, and were the first of their kind found in the Western Hemisphere. Prior to the discovery, researchers had believed this to be a hairless, fast-running species, and the dinosaurs featured as such in the hit film Jurassic Park.
However, interesting theories about the origin of wings have sprung from the examination of the fossils. Although all of the fossils showed evidence of small downy feathers, it seemed that the long feathers, with stiff central shafts were not fully developed until adulthood. This contrasts with birds, where wings generally develop very soon after hatching. This has led to the suggestion that these initial feathers were only used once sexually mature, possible explanations for which, would be that they served a function in courtship, or for brooding.
Researchers have written in Science, that the wing-like forelimbs and feathers are more likely to have developed further, for new purposes such as flying, at a later stage of evolution.
The Daily Mail shows an artist’s impression of the feathered ornithomimid dinosaurs, based on the newly discovered fossil in Canada.
Smart new ways to save ash
A disease that wiped out 90% of Denmark’s ash trees, has been reported in wild trees, for the first time in the UK. The fungus Chalara fraxinea, which causes the disease known as ‘ash dieback’ was reported at two sites in East Anglia, earlier this week. The UK has an estimated 80 million ash trees, which are now at risk.
Experts worry that if the disease becomes established, it could have as devastating an impact as Dutch elm disease had in the 1970s. Most of the mature population of English elm were wiped out by the 1980s. Although the species is now in recovery, this is thanks to considerable effort and husbandry.
The government has already confirmed a ban on all ash imports coming in to the country, but academics and software developers have found their own inventive way to try and stop the spread.
The Guardian describes how the public are being asked to use their smart phones, to map the spread of the disease. The AshTag app has been created, which allows users to report suspected cases of infection. Clues that the infection has taken hold include lesions on their bark, dieback of leaves at the tree’s crown, and leaves turning brown. The last sign is unfortunately, easy to confuse with the natural autumnal changes going on across the landscape. Users can submit photos and locations through the app, and suspected cases will be referred to the Forestry Commission
It is not yet clear whether the outbreak is due to infected imported trees being planted in the wild, or whether the fungus could have been carried in the wind, or with migrating birds, but the App creators hope the citizen-science project may assist all those trying to prevent the disease from spreading any further.
A new study suggests that women who have settled down with a stable but less attractive partners, may subconsciously struggle with that decision during their most fertile times of the month.
The University of California study looked at a small sample of female students in long-term relationships, and tracked their menstrual cycles, whilst routinely asking them to rate the attractiveness of their partner, and the level of satisfaction with their relationship. The results showed that the women who had less attractive partners rated their “closeness in the relationship” to be 15% lower, during their most fertile period, compared to the rest of their cycle. In contrast, the opposite effect was seen in women with attractive partners.
A second stage of the study was repeated with 67 new participants, adding additional questions asking the women to rate their partners’ flaws. Again, women paired with less attractive men were shown to be more likely to find fault with their partners during their high-fertility period. The Independent describes this unfortunate predicament “by one of nature’s cruel ironies, facially challenged chaps are most likely to get a hard time from their wives at the time of the month when she is most fertile.”
Researchers have theorised that the negative feelings may be the result of the compromise women make when they choose a mate, between one who is steady and reliable, and one who is attractive (after all, not all will be lucky enough to find partners who fall in to both categories!). The women may regret this trade-off during their most fertile times.
However it’s not all bad news for men who, as the Independent puts it, “were at the back of the queue when good looks were handed out”. The researchers say “Mr Stable” doesn’t need to worry too much, as the negative feelings during ovulation don’t seem to impact on long-term commitment. Doctoral student Christina Larson, carrying out the study, explains "The negative feelings appear fleeting, and they don't seem to affect a woman's long-term commitment to her romantic relationship. Even when these women are feeling less positive about their relationship, they don't want to end it."