Fossil biological origin

Molecular fossils have been successfully identified in younger Precambrian rocks and linked to certain classes of biological source material. In organic analyses of ancient sediments the cleaned, pulverized rocks are treated with organic solvents to extract a soluble fraction containing the less complex and more easily identifiable compounds. However, this fraction is more subject to contamination since it is not locked within the rock matrix. Normal alkanes have been identified in extracts of the 3 billion year old Fig Tree Shale. These alkanes have a probable biological origin in cellular lipids. The odd and even-numbered alkanes are evenly distributed, a characteristic of alkanes from ancient rocks. It is uncertain, however, whether these compounds were present at the time of deposition or derived from a later source [24]. 

Biomass Organic, non-fossil material of biological origin constituting a renewable energy source. The biomass can be burnt as fuel in a system that creates steam to turn a turbine, generating electricity. For example, biomass can include wood chips and agricultural crops. 

The origin of atmospheric methane can be estimated by determining its, 4C isotope abundance. This abundance should be the same as the l4C content of living plants, if methane is of biological origin or is provided by recently dead organisms. CH4 from fossil fuels or volcanic activity is practically free of radiocarbon, since fuel deposits are very old and their 14C content has already decayed. Measurement of... 

Figure 12-4 will now be discussed in more detail. The record of reduced carbon in sedimentary rocks and the associated, 3C/I2C isotope shift date back to the oldest deposits of 3.5 Gyr ago, and even further if one makes allowance for the metamorphic alterations of the still older Isua formation (see Fig. 11-2). The biological origin of the isotope shift has been convincingly demonstrated, as reviewed by Schidlowski et al (1983). The implication that life had been in full swing 3.5 billion yr ago is supported by several lines of fossil evidence stromatolites, microfossils, and banded iron formations.

Biofuels are defined as fuels of biological origin obtained renewably from organic residues. They can partly replace fossil-derived fuels (i.e., oil) because they can be used in current internal combustion engines and are compatible with the infrastructure that exists now. Biofuels have positive carbon balance compared to fossil fuels the CO2 released to the atmosphere is the same, but in the case of biofuels this is offset by the CO2 captured by the plants from which biodiesel is produced occurring in a closed cycle this reduces the contamination of emissions and improves the ambient air quality [313] (Table 11.2). 

Inthelab, a mixture oftypical microbes from this era... E. ChiFruetaL Fossilized iron bacteria reveal a pathway to the biological origin of banded iron formation. 2013. Nat Commun. 4,p. 2050. DOI 10.1038/ncomms3050. 

In spite of the nearly universal acceptability of the chemicals mentioned above as very important intermediate species to obtain various commodity chemicals and products from biomass, it has been stated (Farmer and Mascal, 2014) that no consensus actually exists about the name by which these biomass-derived species should be called. We shall call these chemical species "bio-based platform molecules" following Farmer and Mascal s book chapter from which we also quote their definition. "A bio-based (or bio-derived) platform molecule is a chemical compoxmd whose constituent elements originate wholly from biomass (material of biological origin, excluding fossil carbon sources), and that can be utilized as a building block for the production of other chemicals."... 

T]he Origin of Species proposed a radically new idea, conceiving of time not as a power but as a factor whose effect could be perceived directly in distinct but complementary forms fossils, embryos, and rudimentary organs. The fossil was petrified time the embryo, operative time the rudimentary organ, retarded time. Together these bits of evidence constituted the archives of biological history —... 

---