Molecular studies have changed many of the phylogenetic relationships previously identified by morphological studies. These changes indicate that .
molecular studies are less reliable than morphological studies
molecular studies are extremely time consuming and expensive and really don't add additional information to our understanding of evolutionary history
molecular studies add additional information to morphological studies and improve our understanding of evolutionary history
molecular and morphological studies rarely agree

Molecular studies add additional information about morphological studies and improve our studies about evolutionary history.

Explanation:

Molecular studies is the field of biology that deals with the studies of structures, composition and our cells interact with it molecules like the Nucleic acids, DNA e.t.c

It is more detailed and accurate than morphological studies because morphology deals with structures and shapes only.

In phylogenetics , it is very important to use molecular studies because it will provide detailed information about the genetic contents and it's composition.

Molecular studies add additional information to morphological studies and improve our understanding of evolutionary history

Explanation:

Molecular studies are carried out with the main objective of pointing out and understanding all interactions at the cellular level, including the formation reactions of nucleic acids, proteins, organelles and even how the interactions between these molecules reflect on the functioning and regulation of vital activities of the living organism.

Morphological studies, in turn, have the function of providing body understanding of living beings, through anatomy and histology, promoting very important concepts about how the physical structure of living beings interferes with the activity of their bodies.

The body of living beings is governed by the molecules that make it up, so we can say that molecular and morphological studies are complementary to each other. It is because of this complementarity that molecular studies are able to modify many of the phylogenetic relationships previously identified by morphological studies.