offspring.
All of this fascinates us, and why shouldnât it? Here are two species, closer to us than they are to the gorillas and with whom we share all but 1.5 per cent of our genetic material, whose behaviour is both like and completely unlike our own. But chimps and bonobos are no mere pit stops on the way to becoming human. Since our paths split from a common ancestor 5 million years ago, the genomes reveal that chimps have âevolvedâ more than we have (meaning that more of their genes have changed as a result of selective pressure than ours). Also, they are much more genetically diverse than humans, suggesting that they were once common and we were rare. Whatever small genetic shifts allowed us to stand on our hind legs, freeing our hands to pinch and grip, and our brains to grow, it isnât a lack in the other species, just a difference. And, as Darwin once expressed it, a difference of degree, not of kind.
There are fewer than 200,000 chimps and bonobos left in the wild. The start of their decline predates human intervention, but we havenât helped: more are eaten as bushmeat each year than are kept in all the worldâs zoos. Imagine a world without chimpanzees. Itâs precisely because we can, and they canât, that we should save them.
Cicada
An insect that counts
N obody really understands how they do it, but some species of cicada match their yearly life-cycles to large prime numbers, that is, numbers that can only be divided by themselves and one: 2, 3, 5, 7, 11, 13, 17, etc.
âPrime-number cicadasâ, or magicicadas , from the Greek magos meaning âmagicianâ, are only found in the eastern United States and their nymphs spend years below ground feeding on tree roots. They only reappear to mate every thirteen or seventeen years.
The reason for this mathematical precision is to avoid even-numbered (and therefore predictable) breeding cycles, which their predators could match. By ensuring that trillions hatch on a single evening, but at unpredictable times, they literally swamp their predators, who gorge themselves until they canât face any more, without damaging the cicada population. There are thirty different broods, each of which is timed to hatch at a different time. The thirteen- and seventeen-year cycles only coincide once every 221 years.
In their long underground imprisonment, the larvae use their droppings to create waterproof cells, to help protect them from flooding. Even so, an estimated 98 per cent perish before they feel the urge to hatch. Those that do survive slough off theirchildhood form and mate furiously. Most are dead within a fortnight, providing a huge nitrogen boost for the forest floor.
CICADA HI-FI
Australian cicadas include the Green Grocer, the Floury Baker, the Double Drummer, the Cherry Nose and the Bladder .
Cicadas are easily the loudest insects, but it is only the males who âsingâ and usually only on warm summer days. Some species hit 120 decibels, equivalent to standing in the front row of an AC/DC concert. They can be heard nearly a mile away. Cicadas donât rub their legs like grasshoppers, but make a series of clicks by buckling a pair of membranes, called tymbals, in their abdomens, in the same way we play a wobble board. Their bodies amplify the vibrations.
They often sing in large groups, which makes it impossible for birds to locate individuals, but the main function of the song is to attract a mate (although some have a âprotest songâ which they use if you prod them). Each species has its own distinctive set of calls, which the femalesâ ears tune into.
The nineteenth-century French entomologist Jean-Henri Fabre tried to demonstrate that cicadas were deaf by firing a cannon towards a tree full of them. Their song didnât change, but not because they were deaf. The sound of the cannon was meaningless to them: you canât mate with heavy artillery.
Because of their apparent
All of this fascinates us, and why shouldnât it? Here are two species, closer to us than they are to the gorillas and with whom we share all but 1.5 per cent of our genetic material, whose behaviour is both like and completely unlike our own. But chimps and bonobos are no mere pit stops on the way to becoming human. Since our paths split from a common ancestor 5 million years ago, the genomes reveal that chimps have âevolvedâ more than we have (meaning that more of their genes have changed as a result of selective pressure than ours). Also, they are much more genetically diverse than humans, suggesting that they were once common and we were rare. Whatever small genetic shifts allowed us to stand on our hind legs, freeing our hands to pinch and grip, and our brains to grow, it isnât a lack in the other species, just a difference. And, as Darwin once expressed it, a difference of degree, not of kind.
There are fewer than 200,000 chimps and bonobos left in the wild. The start of their decline predates human intervention, but we havenât helped: more are eaten as bushmeat each year than are kept in all the worldâs zoos. Imagine a world without chimpanzees. Itâs precisely because we can, and they canât, that we should save them.
Cicada
An insect that counts
N obody really understands how they do it, but some species of cicada match their yearly life-cycles to large prime numbers, that is, numbers that can only be divided by themselves and one: 2, 3, 5, 7, 11, 13, 17, etc.
âPrime-number cicadasâ, or magicicadas , from the Greek magos meaning âmagicianâ, are only found in the eastern United States and their nymphs spend years below ground feeding on tree roots. They only reappear to mate every thirteen or seventeen years.
The reason for this mathematical precision is to avoid even-numbered (and therefore predictable) breeding cycles, which their predators could match. By ensuring that trillions hatch on a single evening, but at unpredictable times, they literally swamp their predators, who gorge themselves until they canât face any more, without damaging the cicada population. There are thirty different broods, each of which is timed to hatch at a different time. The thirteen- and seventeen-year cycles only coincide once every 221 years.
In their long underground imprisonment, the larvae use their droppings to create waterproof cells, to help protect them from flooding. Even so, an estimated 98 per cent perish before they feel the urge to hatch. Those that do survive slough off theirchildhood form and mate furiously. Most are dead within a fortnight, providing a huge nitrogen boost for the forest floor.
CICADA HI-FI
Australian cicadas include the Green Grocer, the Floury Baker, the Double Drummer, the Cherry Nose and the Bladder .
Cicadas are easily the loudest insects, but it is only the males who âsingâ and usually only on warm summer days. Some species hit 120 decibels, equivalent to standing in the front row of an AC/DC concert. They can be heard nearly a mile away. Cicadas donât rub their legs like grasshoppers, but make a series of clicks by buckling a pair of membranes, called tymbals, in their abdomens, in the same way we play a wobble board. Their bodies amplify the vibrations.
They often sing in large groups, which makes it impossible for birds to locate individuals, but the main function of the song is to attract a mate (although some have a âprotest songâ which they use if you prod them). Each species has its own distinctive set of calls, which the femalesâ ears tune into.
The nineteenth-century French entomologist Jean-Henri Fabre tried to demonstrate that cicadas were deaf by firing a cannon towards a tree full of them. Their song didnât change, but not because they were deaf. The sound of the cannon was meaningless to them: you canât mate with heavy artillery.
Because of their apparent
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