Predict first. Two species both have the feature. From that alone — just the two of them, and the fact that they both have it — can you tell whether one ancestor had it and passed it to both, or whether each arrived at it on its own?
Eight species
species with the feature: 0
|
fewest times it could have arisen: 0
Get to each of these:
- two species with the feature, and it need only have arisen once
- two species with the feature, and it must have arisen twice
You just built both. Two species, the same feature, both times — and the fewest-origins number came out differently. What made the difference?