Nola eboluzionatzen du ugaztunen tamainak?
Monash Unibertsitateko (AEB) Alistair Evans ikerlariaren lantaldeak aztertu egin du ugaztunen tamainaren eboluzioa azken 70 milioi urteetan, eta datu interesgarriak argitaratu ditu. Adibidez, errazagoa da lehorreko ugaztun batentzat txikiagoa izatea handiagoa izatea baino, eta itsasoko ugaztunen handitze abiadura handiagoa da lurtarrena baino.
Hona hemen datu batzuk: lehorreko ugaztun batek tamaina 100 aldiz handitzeko 1,6 milioi belaunaldi behar dira, tamaina 1.000 aldiz handitzeko bost milioi belaunaldi, eta hamar milioi belaunaldi tamaina 5.000 aldiz handitzeko. Adibidez, saguen tamaina elefanteenaren adinekoa izateko 24 milioi belaunaldi behar dira. Aldiz, ugaztunen txikitzea askoz ere astiroago gertatzen omen da: ugaztun bat nano bihurtzeko 100.000 urte baino ez dira behar.
Baina nola liteke ugaztun batek txikitzeko joera izatea? Batez ere lurralde mugatuetan, irletan adibidez, gertatzen da hori. Janari gutxiago dagoenez, egoera horretara moldatzeko txikiagotzen dira animaliak, eta aldi berean ugaltze-tasa handitzen dute.
They were all in food and drink, seemingly cheerful, but some were nervous between snacks and appetizers. He would receive the prize for the second time, but he would be the first to have it in his hands. And I was nervous because the reminder had to get to the office, damn it.... [+]
Even if things change quickly and vividly, some things don’t change: The Light Awards event is one of them. This is what an outside journalist who has come to this chronicler in need has told him, along with the fact that LUZ has changed a lot before the awards ceremony... [+]
Irureta Azkun made an appointment on behalf of the LAR team:
"One of the thousands who make up the LUZ community has recently told us that sometimes LUZ is dark, that there is hard news that moves it inside. That we're doing a good job, but the bad news is knocking his throat... [+]
Arizona
Actors: Justin Garfield and Jon Plazaola...
WHEN: January 26th.
IN WHICH: The New Culture Center. In the square.
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The couple Margaret (Aitziber Garmendia) and George (Jon Plazaola) leave Idaho to guard the border between... [+]