With predation and carnivory as catalysts, the first known eye appeared in a trilobite during the Cambrian explosion approximately 543 million years ago. This period was a crucible of evolution and teemed with
Now the women began to test the trees—moving leisurely among them, axe in hand, and striking a single quick blow, to see if the sap would appear. The trees, like people, have their individual characters; some were ready to yield up their life-blood, while others were more reluctant. ...
▪ Abstract The Prelude began with the origin of Metazoa, perhaps between 720 and 660 million years ago (mya), and ended with the geologically abrupt appearance of crown bilaterian phyla that began between 530 and 520 mya. The origin and early evolution of phyla cannot be tracked by fossils...
Since the Galactic tides dominate, the half-life should go approximately as a−1. Given this, the half-life of inner Oort cloud comets with an average a value 20% of the outer cloud comets should have a half-life five times greater. The half-life of an Oort cloud varies with ...
Mo is strongly enriched in the black shale, averaging approximately 300 ppm. Samples recovered from the basal Cambrian interval, including chert, are moderately enriched in Mo (19.2 ppm – 188 ppm). Uranium displays variable concentrations through the section from ~300 ppm in phosphate-rich ...
Later, Richard Gordon and I (Mikhailovsky and Gordon, 2020) showed that during the first approximately 3.5 billion years of life's existence (up to the Cambrian Explosion), these frozen accidents were mostly accumulated in the gene pool of the biosphere rather than driving biological evolution ...
The oldest geologic time period is the Cambrian Period which began circa 540 million years ago and ended around 490 million years ago. The Cambrian... Learn more about this topic: Cambrian Explosion | Definition, Timeline & Impact from
The longer answer is that I’ve found myself returning over the last few months to the reason I originally began writing Mediation back in 2006. Over eight years I attempted to negotiate the future of media and communications. The negotiations were between legacy and next-generation media platfo...
5.3 Mg isotope behavior of dolomites at the Sinian-Cambrian transition The Mg isotopic compositions of dolomites in the Xiaoerbulake Formation and Qigebulake Formation are quite different. The δ26Mg value of the dolomites in the Qigebulake Formation is approximately 0.3‰ lighter than that of th...
The relationship between early faunal evolution and the geochemical marine environment of the Ediacaran-Cambrian is key to understanding the mechanisms of the formation of Earth's life structure. This era of great geological significance began with the breakup of the Rodinia supercontinent and the ...