The placement of the spretus lineage could drift anywhere up to the junction with TF/L1Md4, since the current spretus A2 sequence does not cover these positions.
There is no apparent structure in the terminal burst except for the sharing of 6149C by two sequences, which is probably coincidental.
Monc and Musmh are short sequences that are poorly localized because they do not cover many informative positions. Hence, although the upper reaches of the lineage are well populated, there is an essentially unpopulated stretch just prior to the terminal burst.
A2node1,2,3 represent 3 full length nodal sequences that are well supported and separated by 100 bootstraps.
The apparent lineage split leading to 3997 and 3019a is suspected of being a false lineage formed of elements that have independently formed recombinants that acquired TF sequences.
The full length sequences have type In-III A promoters on the terminal burst. Higher up on the tree are type In-II A promoter arrays. AC4101A has a type IV-IV promoter array. Most of Schichman's A promoter evolutionary sequence is therefore contained within this lineage, except for types V and VI.
See Sources of L1 sequences on Datasets page.
663A and B are the same insert represented in a duplicated portion of the genome.
4101A and 5240A are the same insert represented in a duplicated portion of the genome.
Pointers under construction.