In a meta-analysis on 14 studies, Echinacea decreased the odds of developing a cold by 58% and reduced the length of colds by approximately one and a half days.

在14项研究的荟萃分析中显示，紫锥菊能将患感冒的几率降低58%，感冒时间也缩短了大约一天半。

So individuals with mutations that reduced the length of their tails became more successful at life on land, surviving long enough to pass their short tails on to the next generation.

因此，具有突变特性减少了尾巴长度的个体，在陆地上生活得更加成功，他们生存时间很长，将短尾特征遗传给了下一代。