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上一章 书架管理 下一页
21 LIFE GOES ON
    It ISN’t EASY to become a fossil. te of nearly all living organisms—over 99.9percent of to compost doo noto be put to use in some otem. t’s just t is. Even if you make it into t, t don’t get devoured, the chances of being fossilized are very small.

    In order to become a fossil, several t , you must die in tplace. Only about 15 percent of rocks can preserve fossils, so it’s no good keeling over on afuture site of granite. In practical terms t become buried in sediment,  mud, or decompose  exposure to oxygen,permitting ts bones and s (and very occasionally softer parts) to bereplaced by dissolved minerals, creating a petrified copy of ts in  someain an identifiable s aboveall, after tens of millions or per must befound and recognized as someth keeping.

    Only about one bone in a billion, it is t, ever becomes fossilized. If t is so, itmeans t te fossil legacy of all today—t’s 270 millionpeople  fifty bones, one quarter of a completeskeleton. t’s not to say of course t any of tually be found. Bearing inmind t tly over 3.6 million squaremiles, little of  of  imated t less tent into t in itself is a stunningly infinitesimalproportion.  timate t ture in its time and Ricatement (intinction ) t ture in treduces tion to just one in 120,000. Eit sampling of all t Earth has spawned.

    Moreover, t land animals, of course, don’tdie in sediments. ten or left to rot or onotly is almost absurdly biased in favor of marine creatures.

    About 95 percent of all t once li
上一章 书架管理 下一页

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