5372
However , the pronounced effects of a low drug concentration on survival , a highly elastic trait , may better account for the observed population - level response , i . e . , a decrease of r ( m ) , than the effects on fecundity .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None