When did life first appear on Earth and what form did it take? The answer to this intriguing and fundamentally important question lies somewhere within the early Archean rock record. The young Earth was, however, a very different place to that we know today and numerous pitfalls await our interpretation of these most ancient rocks. The first half of this practical guide equips the reader with the background knowledge to successfully evaluate new potentially biological finds from the Archean rock record. Successive steps are covered, from locating promising samples in the field, through standard petrography and evaluation of antiquity and biogenicity criteria, to the latest state of the art geochemical techniques. The second half of the guide uniquely brings together all the materials that have been claimed to comprise the earliest fossil record into an easily accessible, fully illustrated format. This will be a handbook that every Archean geologist, palaeobiologist and astrobiologist will wish to have in their backpack or on their lab-bench.a20 and a40 parts per thousand. ... has for long been taken to be a keystone characteristic for the earliest fossils (e.g., Buick et al., 1981; Schopf, 1999). ... Unfortunately, complex structures do not require complex causes, as shown nearly a century ago by da#39;Arcy Thompson (1917). ... diagram results in a loss of symmetry but a gain in morphological or temporal complexity towards the a#39;chaotic domaina#39; (seeanbsp;...
|Title||:||Early Life on Earth|
|Publisher||:||Springer Science & Business Media - 2009-01-29|