progressive evolution Steady, long-term improvement of evolutionary grade, which has allowed plants and animals to become ever more independent of the aquatic environment in which they first evolved. For example, the sequence bryophyte to pteridophyte to gymnosperm to angiosperm represents a progressive evolutionary trend.

progressive evolution A steady, long-term improvement of evolutionary grade, which has allowed plants and animals to become ever more independent of the aquatic environment in which they first evolved. For example, the sequence bryophyte, pteridophyte, gymnosperm, angiosperm represents a progressive evolutionary trend.

progressive evolution A steady, long-term improvement of evolutionary grade, which has allowed plants and animals to become ever more independent of the aquatic environment in which they first evolved. For example, the sequence bryophyte, pteridophyte, gymnosperm, angiosperm represents a progressive evolutionary trend.

progressive evolution A steady, long-term improvement of evolutionary grade, which has allowed plants and animals to become ever more independent of the aquatic environment in which they first evolved.