Universal Common Descent
"Common descent" is another way of saying "common ancestry". Universal common descent is the concept that all living things known to science share common ancestry. This cannot be proved (if for no other reason than that unrelated organisms may have been eaten!) but a convincing disproof would be sensational news to biologists.
Baraminologists accept common descent "within the kinds" — that is, within the kinds mentioned in Genesis — a kind of limited evolution. See more at Baraminology and The Origin of the YEC Hyper-Speciation Model of Biological Diversity.
See Common Descent — MCo
Common Descent vs. Common Design
This article by Jim Stump at Biologos: Common Descent vs. Common Design: 4 Examples Explained Better by Descent considers the following cases in some depth:
- Mammalian Skeletons
- Amino Acid Specification
- Vitamin C Producing Genes
- Mutation Signatures