The human stories behind scientific advances can teach us a lot about the miraculous ecosystem that drives progress—about the roles of serendipity and planning, of pure curiosity and practical application, of hypothesis-free and hypothesis-driven science, of individuals and teams, and of fresh perspectives and deep expertise. cell 
Mojica found a curious structure—multiple copies of a near-perfect, roughly palindromic, repeated sequence of 30 bases, separated by spacers of roughly 36 bases—that did not resemble any family of repeats known in microbes. (Mojica et al., 1993).
Mojica realized that the presence of such similar structures in such distant microbes must signal an important function in prokaryotes. (Mojica et al., 1995)
Mojica realized that CRISPR loci must encode the instructions for an adaptive immune system that protected microbes against specific infections. 18 mo later, (Mojica et al., 2005).
Christine Pourcel discovered the strains occasionally differed by the presence of new spacers, which were invariably acquired in a polarized fashion at the “front” end of the CRISPR locus (Pourcel et al., 2005)
Alexander Bolotin also published a paper describing the extrachromosomal origin of CRISPR. (Bolotin et al., 2005)
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In early 2013, Google searches for “CRISPR” began to skyrocket—a trend that has continued unabated. Within a year, investigators had reported the use of CRISPR-based genome editing in many organisms—including yeast, nematode, fruit fly, zebrafish, mouse, and monkey.
The once-obscure microbial system—discovered 20 years earlier in a Spanish salt marsh—was now the focus of special issues of scientific journals, headlines in the New York Times, biotech start-ups, and international ethics summits (Travis, 2015). CRISPR had arrived.
# Lessons
Medical breakthroughs often emerge from completely unpredictable origins.
Growing role in biology of “hypothesis-free” discovery based on big data.
Seminal work near the very start of scientific careers. Several cases before the age of 30.
Landmark work in places that some might regard as off the beaten path of science.
Scientific breakthroughs are rarely eureka moments.
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The CRISPR/cas9 system has created opportunities that could be used for both for good and for ill. Unlike many scientists who leave the ethical implications of their research to others, Jennifer Doudna has decided to engage with her critics. bbc
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A Crispr Conundrum: How Cells Fend Off Gene Editing. Discovery that one gene, p53, largely responsible for preventing Crispr from working. nyt