Is it terrible if humans become extinct provided another species replaces us, whether it’s a carbon- or silicon-based life-form? Well, sucks for me and for you magpies as well, but it’s not nearly as bad as nothingness if we’re ranking such things. From Neil Levy at Practical Ethics:

“I think that reflecting on the end of humanity gives some support to views according to which it is not death itself that matters; rather it is the cessation of some kind of ongoing project. Compare two different scenarios in which humanity comes to an end. In scenario 1, humanity comes to an end in 300 years time when a large asteroid collides with the Earth, causing immediate devastation and a long winter in which the remnants of humanity die off. In scenario 2, humanity comes to an end because we encounter and interbreed with space-faring aliens. I think it is clear that scenario 2 is far preferable to scenario 1, and not just because scenario 1 involves suffering (indeed, if we remove the suffering from scenario 1 – the asteroid somehow triggers instant and painless death – 2 remains far preferable to 1). That suggests that what matters for us is not whether humanity comes to an end, but whether our current projects are in vain. If everything we strive for makes no difference, some kind of meaninglessness seems to threaten, but if our projects continue then they might matter beyond their more immediate effects.”