in very little abundance =?

Context:

"These methods do not capture alternative DNA structural forms that may exist for only a millisecond or in very little abundance, such as one percent of the time," said Al-Hashimi. "We took new solution NMR methods that previously have been used to study rare deformations in proteins and adapted them so that they could be used to study rare states in nucleic acids. Now that we have the right tools to look at these so-called excited states, we may find other short-lived states in DNA and RNA."