Wills argues that certain malarial parasites are especially (i)____________ because they have more recently entered humans than other species and therefore have had (ii)____________ time to evolve toward (iii)____________. Yet there is no reliable evidence that the most harmful Plasmodium species has been in humans for a shorter time than less harmful species. A. populous B. ample C. virulence D. malignant E. insufficient F. benignity G. threatened H. adequate I. variability