This is a grammar question regarding the verb, CONSERVE. Webster's dictionary says it is a transitive verb, and I have always heard it used in the transitive sense, for example,

"I conserve fuel."

But, I have just heard a laboratory researcher use it in the intransitive sense:
"In light of the evolutionary process, the organ system in the fruit fly, like the organ system in the human, is conserved throughout evolution."
Is Webster's dictionary incorrect? Should the dictionary list CONSERVE as both transitive and intransitive?