Intron Losses are More Frequent Than Insertions
Features of Model | Number of Introns Lost | Total Introns | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Model | fog-3 In # 7 | cpb-2 In # 2 | Never | Once | Twice | Lost | Gained | Ratio of Loss/Gain | ||||
| 1 | Independent | Ancestral | 23 | 4 | 7 | 18 | 2 | 9.0 | ||||
| 2 | Independent | Inserted | 23 | 5 | 6 | 17 | 3 | 5.7 | ||||
| 3 | Ancestral | Ancestral | 23 | 5 | 6 | 17 | 2 | 8.5 | ||||
| 4 | Ancestral | Inserted | 23 | 6 | 5 | 16 | 3 | 5.3 | ||||
[i] Because there are two ambiguities in the phylogeny of these introns, four different models that explain the pattern of intron evolution are possible.