Is there a difference in meaning between "remain to be solved" and "remain to solve"?

Context:

While there are many imperfections of the fossil record, and many puzzles remain to be solved, virtually all of the findings
are consistent with the concept of a tree of life of related organisms. Good evidence exists for transitional forms from reptiles to birds, and from reptiles to mammals. Arguments that this model cannot explain certain species, such as whales, have generally fallen by the wayside as further investigation has revealed the existence of transitional species, often at precisely the date and place that evolutionary theory would predict.