The Malaysian Insider :: Features
The Malaysian Insider :: Features |
| It’s good news for Global Tiger Day Posted: 29 Jul 2013 07:47 PM PDT The survey, stated news agencies, which was carried out between February and June, assessed the Bengal tiger population across a 600-mile stretch in Nepal and India. It found numbers had increased in all of Nepal's national parks. In particular, the tiger population in the south-western Bardia national park has risen from about 18 in 2009 to 50 this year. Global Tiger Day, which falls on July 29 annually, is also known as International Tiger Day. According to the World Wildlife Fund, over the last century wild tiger numbers have fallen disastrously, by more than 95% - mainly due to poaching and the destruction of forests and other habitats they need for survival. South Asian governments have committed to doubling tiger populations by 2022, but the animals continue to face threats from poaching and habitat loss. There are thought to be fewer than 2,000 tigers left worldwide, with 60% of them in India, reported The BBC. The survey covered tigers in the Terai Arc region, which spreads across the north Indian states of Bihar, Uttar Pradesh and Uttarakhand and into southern Nepal. Nepal's survey concentrated on five protected areas and three wildlife corridors. Nepalese officials described the findings as a "milestone" in the bid to double the number of wild tigers by 2022, as agreed by the region's leaders at an international summit in 2010. Tens of thousands of Royal Bengal tigers, the most numerous subspecies of tiger, used to roam Bangladesh, Bhutan, India and Nepal, but their numbers have fallen dramatically in recent decades. The tiger's massive decline is due to widespread deforestation, the shrinking of their habitat and loss of prey base, as well as illegal poaching and wildlife trade. Earlier this year, a study by Cardiff University warned that Indian tigers could face extinction because of a collapse in the variety of their mating partners. The study found that 93% of DNA variants found in tigers shot during the period of the British Raj are not present in tigers today. Researchers say a loss of habitat has meant that tigers are no longer free to roam throughout the subcontinent, which in turn has restricted their gene pool. For the next Year of the Tiger, in 2022, the WWF is asking the governments of tiger range countries to commit to a series of global wild tiger counts. It said that three comprehensive counts are needed – in 2016, 2020 and 2022. "Tiger range countries have set an ambitious goal and WWF is committed alongside them to make it a reality," says Mike Baltzer, leader of WWF's Tigers Alive Initiative. "To know global tiger population numbers will be to know where we are... and will help understand what else we need to do together to put tigers in a safe place by 2022." – July 30, 2013. |
| For men, monogamy can have evolutionary benefits Posted: 29 Jul 2013 04:39 PM PDT Whenever a public figure cheats on his wife, pundits can be counted on to trot out the tired old claim that males are simply wired by evolution to be promiscuous. Two studies released yesterday beg to differ. By sticking to one female, they conclude, males of many species, especially primates, can increase their chances of siring many offspring who survive long enough to reproduce - the key factor in determining whether a particular behaviour survives the brutal process of natural selection. In fact, the evolutionary advantages to males of being monogamous are so clear that the two studies reached competing conclusions about which benefit is greater for males. According to research published in the Proceedings of the National Academy of Sciences, protecting the lives of his offspring was the paramount benefit of monogamy. Separate findings published in the journal Science said that keeping his mate faithful provided the greatest evolutionary edge. Both studies addressed a conundrum: because male mammals can sire so many more offspring per breeding season than females, it would seem that mating with only one female would be less adaptive for a male than spreading his seed widely. The PNAS paper, which analysed 230 species of primates, concludes that protecting the kids is the greatest benefit of male monogamy. By sticking close to his mate a male reduces the risk of infanticide. Although the study examined only nonhuman primates, that reasoning has resonance in people, too, where children who grow up without a father in the household are more likely to die in childhood, according to government statistics. "This is the first time that the theories for the evolution of monogamy have been systematically tested, conclusively showing that infanticide is the driver of monogamy," said anthropologist Christopher Opie of University College London, lead author of the PNAS paper, which analysed 230 species of primate. "This brings to a close the long-running debate about the origin of monogamy in primates." Not so fast, according to authors of the Science paper. Zoologists Dieter Lukas and Tim Clutton-Brock of the University of Cambridge examined the social structure of 2,545 species of mammals, of which 9 percent are socially monogamous. That was defined as a system in which a male mates with only one female and they "usually stay together until one dies," Lukas told reporters. The Cambridge scientists conclude that guarding against infanticide played little if any role in the development of monogamy among such mammals as tamarins, marmosets, beavers, wolves, jackals and meerkats. Instead, the behaviour arose when females spread out over large territories and had zero tolerance for other females entering their turf. That left a male little choice but to stick close to his mate, foreswearing others, because philandering risked leaving her to the sweet entreaties of a rival. "Monogamy arose where guarding a single female was a male's best reproductive strategy," said Clutton-Brock. EVOLUTIONARILY ADVANTAGEOUS Once monogamy set in for this reason, the care that faithful fathers provide their offspring can make the behaviour even more evolutionarily advantageous, since it increases their brood's chances of surviving. In fact, the two studies are not that far apart, starting with their basic conclusion that male monogamy can be a winning strategy, evolutionarily, and thus be favored by natural selection - the "survival of the fittest" winnowing process that shapes species. Both studies also found that paternal care "is a consequence, not a cause, of monogamy," said Clutton-Brock, but one that made it even more beneficial: with monogamy, males are more likely to help care for their offspring. That not only protects against murderous marauders but takes some of the burden of childcare from mum, preserving her health and allowing her to bear more healthy offspring, which count as additional evolutionary points for the faithful dad too. It will take more research to sort out which evolutionary force - preventing infanticide or guarding against cuckoldry -had the strongest effect on the development of monogamy among some mammals. The research is even less able to speak to monogamy - or the lack of it - in people. The Cambridge team believes that "humans are not socially monogamous," said Lukas, while the PNAS authors classify humans as both monogamous and polygamous, depending on their historical and social circumstances. "Humans are such unusual animals, depending so excessively on culture, which changes so many of the ground rules of evolution," said Clutton-Brock. Human monogamy might have arisen when females were separated and solitary, and a male needed to stick close to one mate to guard her, added Lukas, "but it is also possible that monogamy is a very recent, cultural arrangement of marriage within groups." Whatever the initial reason and whenever it evolved, monogamy has been a boon for Homo sapiens. The study pointing to protection from infanticide as the prime force in male monogamy "allows us to peer back into our evolutionary past to understand the factors that were important in making us human," said Susanne Shultz of the University of Manchester, a co-author of the PNAS paper. "Once fathers decide to stick around and care for young, mothers can then change their reproductive decisions and have more, brainy offspring." – Reuters, July 30, 2013. |
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