Kathy, Thanks for asking!
The best way is to get DNA testing for any male Dalrymple in your family. To join the Dalrymple DNA group, it must be a male who was born as a "Dalrymple." Male Dalrymples purchase Y-DNA at Family Tree DNA. Here is the link: www.familytreedna.com
Best choice is the 37 Y-DNA markers. If you want to go the whole way - choose the 67 Y-DNA markers. This is quick and easy. The site can also answer any questions you might have. This is private testing and strictly addresses genealogical testing - NOT medical!
If I can help further, just let me know. Carolyn Achata monitors the Dalrymple DNA group. I hope you have a male who can participate!