Telling the Evolutionary Time: Molecular Clocks and the Fossil Record

collected in recent years that have significantly extended their times of origin. In the case of animals, body fossils have been ...

Neoproterozoic Snowball Earth events Several global glaciations (Snowball Earth events) occurred during the Neoproterozoic, from ...

generally believed. If molecular clock estimates are correct, major lineages of animals and fungi survived the Snowball Earth ev ...

tardigrades, which themselves could be classified as extremophile eukaryotes, sometimes are found in symbiosis with lichens and ...

of such carbon would have lowered levels of carbon dioxide and global temperature. Some prokaryotes, such as cyanobacteria, are ...

extensive recovery that generated a major pulse of oxygen. This may go some way towards explaining the Cambrian explosion of ani ...

Brown, R.H., Richardson, M., Boulter, D., Ramshaw, J.A.M. and Jeffries, R.P.S. (1972) ‘The amino acid sequence of cytochrome c f ...

Hoffman, P.F., Kaufman, A.J., Halverson, G.P. and Schrag, D.P. (1998) ‘A Neoproterozoic snowball Earth’, Science, 281:1342–6. Ho ...

Ohmoto, H. (1997) ‘When did the Earth’s atmosphere become oxic?’, The Geochemical News, 93: 12–26. Rasmussen, B., Bengston, S., ...

Wray, G.A., Levinton, J.S. and Shapiro, L.H. (1996) ‘Molecular evidence for deep Precambrian divergences among metazoan phyla’, ...

Chapter 3 Phylogenetic fuses and evolutionary ‘explosions’: conflicting evidence and critical tests Richard A.Fortey, Jennifer J ...

which molecular phylogenies and ‘clocks’ may be used to test them. The latter come with another battery of qualifications. We ar ...

there is no suggestion of small and cryptic ancestors, there is no suggestion either of a ‘phylogenetic fuse’. The examples of e ...

at a phylogenetic history antedating the first record of fossils. Connections at a still deeper level (e.g. between phyla) are i ...

that of the origin of clades. Molecular tests of rate constancy and divergence times can, in principle, distinguish between thes ...

Cambrian—because on their definition phyla appear in younger strata. They effectively reduce the length of the phylogenetic ‘fus ...

Relationships between major groups More disturbing, perhaps, is the lack of consensus on phylogenetic relationships using either ...

genes and nuclear rRNA in resolving deep divergences and providing rate estimates, they add a level of complication due to gene ...

upward bias, and that distances based on concatenated sequences may help reduce this bias. Pairwise distance methods have common ...

is that the majority of fossil-based divergence times are underestimates. If supposedly ‘accurate’ calibration points are used i ...