Darwinism designates a distinctive form of evolutionary explanation for the history and diversity of life on earth. Its original formulation is provided in the first edition of On the Origin of Species in 1859.
The enthalpy - or internal energy - of a substance is a function of its temperature and pressure. The change in internal energy with respect to change in temperature at fixed pressure is the Specific Heat at constant pressure - cp.
The enthalpy of hydration is always exothermic, since it involves bond making. The lattice energy contribution is always endothermic, since it involves breaking the ionic bonds between the positive and negative ions in the molecule.