  We present an ab initio calculation of the quark mass dependence of the
ground state energies of ^4He, ^8Be and ^{12}C, and of the energy of the Hoyle
state in ^{12}C. These investigations are performed within the framework of
lattice chiral Effective Field Theory. We address the sensitivity of the
production rate of carbon and oxygen in red giant stars to the fundamental
constants of nature by considering the impact of variations in the light quark
masses and the electromagnetic fine-structure constant on the reaction rate of
the triple-alpha process. As carbon and oxygen are essential to life as we know
it, we also discuss the implications of our findings for an anthropic view of
the Universe. We find strong evidence that the physics of the triple-alpha
process is driven by alpha clustering, and that shifts in the fundamental
parameters at the \simeq 2 - 3 % level are unlikely to be detrimental to the
development of life. Tolerance against much larger changes cannot be ruled out
at present, given the relatively limited knowledge of the quark mass dependence
of the two-nucleon S-wave scattering parameters. Lattice QCD is expected to
provide refined estimates of the scattering parameters in the future.
