None. The only reason we feel it has some value is because we are descendants of humans who believed it. Humans who didn’t feel or think our life has value didn’t survive, and now through natural selection we naturally believe it as well. If our planet was destroyed along with humanity, zero fucks would be given by the Universe. The supposedly infinite value of human life is just the story we tell ourselves. By extension we believe that everybody’s life is also equally valuable – this is another story we’ve been telling ourselves since the Renaissance mostly in order to fight with inequalities like monarchies. Clearly if we were to choose between life of Einstein and life of Hitler, the choice would be obvious. We believe in many stories that make us feel good about ourselves. Intrinsic value of human life is just one of them.