Every species has its instinct for self-preservation. In man, however, it is not a blind urge but a rational desire that places inestimable value on human life. Why? Science [1] has no answer to that philosophical/religious question. Nor is the reference to Darwinism at this point out of place. It continues to motivate the space program.
Links:
[1] https://www.thebereancall.org/taxonomy/term/58/science