  The goals of the astrobiology community are focussed on developing a
framework for the detection of biosignatures, or evidence thereof, on objects
inside and outside of our solar system. A fundamental aspect of understanding
the limits of habitable environments and detectable signatures is the study of
where the boundaries of such environments can occur. Thus, the need to study
the creation, evolution, and frequency of hostile environments for habitability
is an integral part of the astrobiology story. These provide the opportunity to
understand the bifurcation, between habitable and uninhabitable. The archetype
of such a planet is the Earth's sister planet, Venus, and provides a unique
opportunity to explore the processes that created a completely uninhabitable
environment and thus define the conditions that can rule out bio-related
signatures. We advocate a continued comprehensive study of our sister planet,
including models of early atmospheres, compositional abundances, and
Venus-analog frequency analysis from current and future exoplanet data.
Moreover, new missions to Venus to provide in-situ data are necessary.
