The atmosphere of the Archean eon—one-third of Earth's history—is important for
understanding the evolution of our planet and Earth-like exoplanets. New geological proxies …

Biodiversity on Earth is strongly affected by human alterations to the environment. The
majority of studies have considered aboveground biodiversity, yet little is known about …

The early Earth's environment is controversial. Climatic estimates range from hot to glacial,
and inferred marine pH spans strongly alkaline to acidic. Better understanding of early …

The past several years have seen novel insights at the interface of protein biophysics and
evolution. The accepted paradigm that proteins can tolerate nearly any amino acid …

Construction and assembly of the Geologic Time Scale involves:(a) constructing a relative
(chronostratigraphic) standard scale for key periods in the Earth's rock record;(b) identifying …

Uricase is an enzyme involved in purine catabolism and is found in all three domains of life.
Curiously, uricase is not functional in some organisms despite its role in converting highly …

Differential scanning calorimetry measures the heat capacity of states and the excess heat
associated with transitions that can be induced by temperature change. The integral of the …

Natural proteins are often only slightly more stable in the native state than the denatured
state, and an increase in environmental temperature can easily shift the balance toward …

With early life likely to have existed in a hot environment, enzymes had to cope with an
inherent drop in catalytic speed caused by lowered temperature. Here we characterize the …

Studies of evolution at the molecular level have experienced phenomenal growth in the last
few decades, due to rapid accumulation of genetic sequence data, improved computer …