Acactus with long spines protects itself from animals better than a cactus with short spines. according to natural selection,
short-spined cacti will survive longer and reproduce more often than long-spined cacti
long-spined cacti will survive longer and reproduce more often than short-spined cacti
over time, the population will become entirely made of short-spined cacti
over time, cacti with long spines will completely die out

Long-spined cacti will survive longer and reproduce more often than short-spined cacti. Because natural selection suggests that organisms with certain traits that give them better chance at survival or reproductive rate will be pass on to their offspring.

This is s cute awee : (( . well if she's showing you signs that she may like you , then shoot your shot ! don't be afraid . & if you're unsure that she's giving you these signs , then wait out for a little bit . most girls are different . some may act really sweet , but only bc you're a good friend of hers . that , or she might like you . you just never know . but i think you should sit down with her & tell her how you feel . but don't be awkward & shy . just be straight up & tell her how you feel . if the feelings aren't mutual , then don't cry about it . you need to respect her decision & look for others in the world . feelings can be difficult & confusing , but don't be afraid to show them . i say you play it out & if you're still unsure about it , talk to her . - rach

The rate that would change would be the  searching efficiency/attack rate. there are only two other rates in this model: the  growth rate of prey, and the  predator or consumer mortality rate.the  searching efficiency/attack rate is what indicates how effectively can a predator capture its prey whether in the searching process or actual capturing/attacking process.