A series of appointments in the Organismic and Evolutionary Biology Department which will eventually add four new faculty experts in plant or animal systematics began to take effect last week, department member said.

Michael J. Donoghue of the University of Arizona officially joined the faculty as a full professor in January 1993, having accepted a tenure offer in late 1992. But he was on a Mellon Fellowship at the Smithsonian Museum this spring, and arrived in Cambridge to begin his job July 1, according to department administrator Jay L. Taft.

Two new associate professors of biology officially began work on July 1, Taft said; Elizabeth A. Kellogg '73, who was a research associate at Harvard, and John E. Cadle, who was assistant curator at the Academy of Natural Science in Philadelphia.

David A. Baum of the University of Wisconsin will come to the faculty on July 1, 1994 as an assistant professor, joining Kellogg and Donoghue as part of a series of appointments in the area of plant biology intended to strengthen the discipline after several retirements left slots open in he department, said Gray Professor of Systematic Biology Donald H. Pfister.

"The department is also interested in the broad questions of species concepts," Pfister said. "We're all looking and seeing the appointments as being really central to developing plant biology...and philogeny."

Pfister said Donoghue is well-known in the field for his work with philogenetic trees, the analysis of the relationships between different vascular plants in a broader evolutionary context. He said Donoghue is also working with molecular techniques important in molecular philogeny, which studies how molecular characteristics and components of different groups explain group evolution.

Kellogg, Pfister said, has been concentrating on evolution among different classes of grasses. Baum's specialty is floral development, specifically the subset called baobabs found in Madagascar and Australia.

Taft said a fourth offer had been made in the field of plant biology that was still uncertain, but would not give the name of the prospect.

Cadle is the only one of the four acceptants who specializes in animal rather than plant biology. Cadle's discipline is herpetology, the study of amphibians and reptiles. "I had an informal offer more than a year ago," he said. "The official offer came sometimes late last summer...I accepted in February."

He said he believes the four new appointments represent a stronger emphasis in the department on systematics, which he described as the study of evolutionary history of life in order to learn about current characteristics of the group.

"Certainly systematics has become revitalized in recent years...there have been a lot of conceptual advances," Cadle said. "In recent years it has become more integrated with evolutionary biology and molecular biology. All the new appointees do molecular biology as well."

Cadle, who is also the assistant curator in the Museum of Comparative Zoology, said he has spent most of his first full week at Harvard trying to get his office organized. But the said he plans to involved in the teaching of a few undergraduate courses the year after next