1992-present:
| Full professor of Biology and History & Philosophy of Science (with tenure). Redeemer University College. Canada. |
| 1988-99: | Co-founder and Director, Pascal Centre for Advanced Studies in Faith and Science. |
| 1984-92: | Associate professor of biology. Redeemer College. Canada. |
| 1983-84: | Assistant professor of biology. Redeemer College. Canada. |
1982-83:
| Assistant professor of biology and chemistry. Redeemer College. Canada. |
| 1981-82: | Visiting assistant professor of biology. Purdue University. Indiana. U.S.A. |
| 1980-81: | Research scientist. Purdue University. |
1979-80:
| Postdoctoral research associate. Purdue University. |
| 1978-79: | Postdoctoral research fellow. University of Heidelberg. FRG. |
| 1972-78: | Research associate. Catholic University of Nijmegen. N.L. |
