Beschreibung:
<jats:title>Abstract</jats:title><jats:p>It is reasonable to believe that life exists in many places throughout the Universe. Among the many billions of heavenly bodies, there are galaxies with millions of stars that may harbor lower or even higher forms of living organisms («life» in the meaning as we know it, e.g., carbon chemistry, liquid water etc.). This article lists Extremophiles and their various terrestrial enigmatic environments. We discuss the possibilities of Martian life and the origin and evolution of the eukaryotic cell and present some early protists and the Acidothermophilic algae. Among several microbes which can «fit» for extraterrestrial life, one eukaryotic algal group (Cyanidiophyceae) is treated here. The hot spring<jats:italic>Cyanidium caldarium</jats:italic>members (there are three genera and several species in this family) thrive in excessive growth conditions like in acidic medium (close to IN H<jats:sub>2</jats:sub>SO<jats:sub>4</jats:sub>), under pure CO<jats:sub>2</jats:sub>atmosphere, in elevated temperature and auto or heterotrophic conditions. These hot spring unicellular algae do not require oxygen for such conditions of growth. Studies have shown that they present one of the earliest and simplest eukaryotic algae. Also, these microbes may be candidates for existing on planets with similar ecological conditions which might support life forms.</jats:p>