| Date | November 2015 | Marks available | 1 | Reference code | 15N.3.HL.TZ0.2 |
| Level | Higher level | Paper | Paper 3 | Time zone | TZ0 |
| Command term | Label | Question number | 2 | Adapted from | N/A |
Question
The diagram shows part of a cladogram for invertebrate species from the Cambrian age.
On the cladogram, label with the letter C the point that shows the most recent common ancestor of Pambdelurion and Fuxianhuia.
Identify which two species evolved most recently.
Markscheme
Leanchoilia and Euarthropoda
Examiners report
A large number of candidates had some difficulty labelling the common ancestry in the cladogram correctly, either because their label was not precise enough, even if they understood it (e.g. label at the right of Pambdelurion), or because they could not interpret it at all. It was easier for them to identify the two species that evolved more recently at the bottom of the cladogram, although some might have done it by chance due to their position on the cladogram.
A large number of candidates had some difficulty labelling the common ancestry in the cladogram correctly, either because their label was not precise enough, even if they understood it (e.g. label at the right of Pambdelurion), or because they could not interpret it at all. It was easier for them to identify the two species that evolved more recently at the bottom of the cladogram, although some might have done it by chance due to their position on the cladogram.
