Reductions in the population size of the graceful antelope, a hypothetical species, has led to inbreeding. deleterious after-effects of that inbreeding are leading to further decreases in the population size of this species. this pattern is an example of a(n)

I believe this is an example of an extinction vortex. Extinction vortex is used to describe the process that declining populations undergo when a mutual reinforcement occurs among biotic and abiotic processes that drives population size downward to extinction. Through it conservation biologists, geneticists and ecologists can understand the dynamics of and categorize extinctions in the context of their causes. 

There would be one bar shorter than the bar for peaches.

Diagrams for sure 67(8? ; 4