墨尔本PTE Summarize written text 总结归纳段落 14

Read the passage below and summarize it using one sentence. You have 10 minutes to finish this task. Your response will be judged on the quality of your writing and on how well your response presents the key points in the passage.

Humans have been cultivating chillies as food for 6,000 years, but we are still learning new things about the science behind their heat and how it reacts with our body. In the late 19905, scientists identified the pain nerves that detect capsaicin: the chemical in chillies responsible for most of the burning sensation in our mouth. But it’s only during the last few years that scientists have also learnt why chillies evolved to be spicy in the first place, and they have managed to cultivate new varieties that are up to 300 times hotter than the common Jalapeno.

The hottest part of a chilli is not the seeds, as many people think, but the white flesh that houses the seeds, known as the placenta. But why did chillies evolve to be hot in the first place? Most scientists believe capsaicin acts mainly as a deterrent against would-be mammal predators such as rodents. But recent research suggests this may not be the whole story. US scientists working in Bolivia have studied how hot and mild chillies differ in their susceptibility to a certain harmful fungus. It turns out that the hotter the chilli, the better its defences against the fungus, leading the researchers to propose that heat may have evolved to help chillies deal with harmful microbes, as well as hungry mammals.