GEOL 107 Lecture Notes - Lecture 7: Archaea, Pyrite, Scientific American

• School: Queen's University
• Department: Geological Sciences and Geological Engineering
• Course: GEOL 107
• Professor: Guy Narbonne

Document Summary

Ga: oceans had formed by 4. 2 ga at the latest it seems unlikely that there was life on the surface of the earth prior to 3. 8 ga since the great. We will explore this more fully in lecture 25: oldest definite fossils dated at 3. 5 ga, occur in the oldest reasonably undeformed sedimentary rocks on earth. Tep (cid:1005) for(cid:373)atio(cid:374) of i(cid:373)ple orga(cid:374)i(cid:272) mole(cid:272)ules (cid:894)a(cid:373)i(cid:374)o a(cid:272)ids, nu(cid:272)leotides, ugars(cid:895) a famous example is the miller-urey experiment (cowen, 2013, fig. Step 2 (combining simple organic molecules into complex molecules) has not been done. Tep (cid:1006) co(cid:373)(cid:271)i(cid:374)atio(cid:374) of i(cid:373)ple orga(cid:374)i(cid:272) mole(cid:272)ules i(cid:374)to co(cid:373)plex orga(cid:374)i(cid:272) mole(cid:272)ules (cid:894)dna, Rna, proteins) the most difficult step in synthesis of life and not yet completely resolved: models (summarized in cowen, 2013, pp. Tep (cid:1007) i(cid:374)itiatio(cid:374) of repli(cid:272)atio(cid:374) (cid:894)reprodu(cid:272)tio(cid:374)(cid:895: (cid:862) piegel(cid:373)a(cid:374) mo(cid:374)ster(cid:863) experiment shows that self-replicating living systems can consist of little more than a short strand of rna: Qb virus (rna of 4500 nucleotides) + nucelotides + replicase.