We followed evolutionary change in 12 populations of Escherichia coli propagated for
10,000 generations in identical environments. Both morphology (cell size) and fitness (measured …

… Although social cohesion in M. xanthus is not absolutely obligate before development, it
does move primarily in groups on most laboratory surfaces. Moreover, survival under stress and …

Mechanisms maintaining genetic and phenotypic variation in natural populations are central
issues in ecology and evolution. However, the long generation times of most organisms and …

Successive adaptive radiations have played a pivotal role in the evolution of biological
diversity 1 , 2 , 3 . The effects of adaptive radiation are often seen 4 , 5 , 6 , but the underlying …

Multicellularity was one of the most significant innovations in the history of life, but its initial
evolution remains poorly understood. Using experimental evolution, we show that key steps …

Throughout most of the mammalian genome, genetically regulated developmental programming
establishes diverse yet predictable epigenetic states across differentiated cells and …

Background: The obesity epidemic, recognized in developed nations for decades, is now a
worldwide phenomenon. All age groups are affected, including women of childbearing age, …

… enzyme, enhances the rate of reaction by a factor of 1017 and is estimated to bind the
altered substrate in the transition state with a dissociation constant of less than 5 x 10-24 M. …

The SUC multigene family of the single–celled yeast Saccharomyces cerevisiae is polymorphic,
with genes varying both in number and activity. All of the genes encode invertase, an …

… Louis) Fluorescent Brightner 28] was used in LB at 1-10 μm and cells or the polymer incubated
with the … Cellulase (Sigma) was diluted in 50 mm sodium acetate (pH 5.0) buffer at 37. …