For THOSE who are worried that this may lead to further BLURRING OF the lines between the species, Jane Goodall's words (works? research? thesis?) indicate the reverse is true.

the first one but the second can be said

Both sentences are grammatically sound, however, if I were to use Sentence No. 1, I would put an “a” before “further.” This emphasizes that the lines, which are already blurred, are even more so by whatever “this” is. In terms of their usage, as Chris noted earlier, a Google Ngram Viewer search shows it being approx. 2 to 1 for the latter, while a COCA search shows it being slightly more. Thus, I would say sentence No. 2 is the more natural as more native speaker (and writers) use it.

definitely include the "of"

The 2nd. Blurring the line Crossing the line Better than.. of the..