ABSTRACT
The origin of sex comprises two separate phenomena: the origin of a life cycle that includes meiotic cell division and fusion of gametes, and the origin of maleness and femaleness. This chapter deals with the origin of the elements and its implications for the age of the elements. The predicted concentrations of carbon and still heavier elements are, however, many orders of magnitude smaller than are observed in our galaxy. The evolution of a star is characterized both by element synthesis during various stages of nuclear burning and, ultimately, by the return of processed matter to the interstellar gas by slow mass loss of explosive ejection. Interesting constraints on the age of our Milky Way galaxy can be obtained by diverse means as consideration of the ages of star clusters in the galactic halo, of the ages of the white dwarfs in the immediate vicinity of the sun, and of the age of the elements themselves.
