New Entry by Robert Streiffer on May 21, 2009.] A chimera is an individual composed of cells with different embryonic origins. The successful isolation of five human embryonic stem cell (hESC) lines in 1998 increased scientists' ability to create human/non-human

New Entry by Kristin Gjesdal on May 21, 2009.] The philosophical impact of early German romanticism in general and Georg Philipp Friedrich von Hardenberg (Novalis) in particular has typically been traced back to a series of fragments and reflections on

is the most famous of the logical or set-theoretical paradoxes. The paradox arises within naive set theory by considering the set of all sets that are not members of themselves. Such a set appears to be a member of itself

height.png] A heritable trait is most simply an offspring's trait that resembles the parents' corresponding trait. Inheritance or heredity was a focus of systematic research before its inclusion as a key concept within evolutionary theory. An influential 18th and early