Reproduction is the evolutionary bottleneck, and nature seems to have tried almost every approach imaginable. A highly improbable one is that of the wandering albatross, Diomedea exulans.
Connect With Us on Twitter
For Op-Ed, follow @nytopinion and to hear from the editorial page editor, Andrew Rosenthal, follow @andyrNYT.
This is an immense bird, pelagic and circumpolar, whose life is lived almost perpetually on the wing — on extraordinary wings, in fact, easily reaching 10 feet from tip to tip. Wandering albatrosses can live for more than 50 years. They mate for life, and they breed every two years — laying a single egg — on islands within the Southern Ocean, which surrounds Antarctica.
Recently, scientists from the Institute of Evolutionary Biology in Edinburgh and the British Antarctic Survey made a surprising discovery about patterns of reproduction within this species. Like most species, albatrosses are more successful at rearing their young early in their lives, probably because they are able then to forage more widely and actively than when they are older. This pattern of early reproduction followed by senescence is all too familiar to us. But in albatrosses, something changes late in life.
In their final breeding, they enjoy unusual success rearing one last chick, partly because they support the chick through a longer fledging period than younger parents do. A higher investment in the next generation when "survival prospects are low," the scientists note, is supported by evolutionary theory. And yet the wandering albatross is one of the few species that show this trait, a trait that becomes apparent thanks to the birds' extraordinary longevity, their lifelong pairing, and the positive effect of experience on their ability to care for a chick.
The behavior is instinctive, but how does instinct tell albatrosses that this will be their last chick? Even without an answer, there is something wondrous in the idea of a pair of elderly albatrosses raising a chick with great care, as their own death approaches.
Anda sedang membaca artikel tentang
Editorial: One Last Chick for the Wandering Albatross
Dengan url
http://opinimasyarakota.blogspot.com/2013/03/editorial-one-last-chick-for-wandering.html
Anda boleh menyebar luaskannya atau mengcopy paste-nya
Editorial: One Last Chick for the Wandering Albatross
namun jangan lupa untuk meletakkan link
Editorial: One Last Chick for the Wandering Albatross
sebagai sumbernya
0 komentar:
Posting Komentar