Snowball Earth Events and Evolution of Life
نویسندگان
چکیده
منابع مشابه
Neoproterozoic ‘snowball Earth’ glaciations and the evolution of altruism
We hypothesize that a demographic and ecological effect of Neoproterozoic ‘snowball Earth’ glaciations was to increase the fitness of group-level traits and consequently the likelihood of the evolution of macroscopic form. Extreme and repeated founder effects raised genetic relatedness – and therefore the influence of kin selection on the individuals within a group. This was permissive for the ...
متن کاملBiologically induced initiation of Neoproterozoic snowball-Earth events.
The glaciations of the Neoproterozoic Era (1,000 to 542 MyBP) were preceded by dramatically light C isotopic excursions preserved in preglacial deposits. Standard explanations of these excursions involve remineralization of isotopically light organic matter and imply strong enhancement of atmospheric CO(2) greenhouse gas concentration, apparently inconsistent with the glaciations that followed....
متن کاملA neoproterozoic snowball earth
Negative carbon isotope anomalies in carbonate rocks bracketing Neoproterozoic glacial deposits in Namibia, combined with estimates of thermal subsidence history, suggest that biological productivity in the surface ocean collapsed for millions of years. This collapse can be explained by a global glaciation (that is, a snowball Earth), which ended abruptly when subaerial volcanic outgassing rais...
متن کاملAftermath of a snowball Earth
[1] Using a simple 3-box model of the ocean-atmosphere system, we simulate the cycling of carbon and strontium in the aftermath of a global glaciation. Model simulations include the delivery of alkalinity to seawater from intense carbonate and silicate weathering under high pCO2 conditions as well as ocean mixing, air-sea gas exchange, and biological productivity. The dC of the first carbonate ...
متن کاملOrigins and assessment of snowball Earth hypotheses
Records of Precambrian glaciation onwards from the late nineteenth century led to the concept of one or more major ice ages. This concept was becoming well advanced by the mid 1930s, particularly through the compilation of Kulling in 1934. Even so tillite stratigraphy shows that glaciation was exceptional rather than typical of Earth history. Some Proterozoic tillites, sandwiched between warm m...
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ژورنال
عنوان ژورنال: Journal of Geography (Chigaku Zasshi)
سال: 2007
ISSN: 0022-135X,1884-0884
DOI: 10.5026/jgeography.116.79