I think there is a difference between avoiding death and fearing it. There are also different degrees of fear. There's a healthy aspect, not to mention good survival strategy, to avoiding climbing out on an unstable cliff edge out of fear you might fall to your death. On the other hand, some people fear death to the point they don't bother to live. I think that's counterproductive to survival. If you thought of an analogous example of an animal so afraid it would be eaten by a predator that it never left its burrow, then it would instead starve to death. I have grandparents like that, the kind who has been telling me for the last 30 years, "you better visit because this might be the last time I see you, I could be dead by next year." So, they stay home and wait to die. I guess it's not relevant to species survival, no selection strategy for or against it since they have obviously reproduced and their children have reproduced, and even their grandchildren have reproduced at this point, so it has nothing to do with reproduction or survival of the species, but it sure doesn't seem like a good way to live.