Reticulation in phylomemetics

Practically every phylomemetic tree I have ever seen has illustrated branching - but not joining. However, it is well known that cultural evolution shows a considerable amount of joining. The result is part tree, part reticulated network - rather like the image associated with this post.

Should we be concerned that most phylomemetic trees paint an inaccurate picture of how cultural evolution operates? That most phylomemetic trees are inaccurate - through inheriting this systematic distortion?

On one hand, the fact that most evolution involves joining as well as splitting is an important issue which is poorly understood - and most phylomemetic trees reinforce the idea that evolution equals splitting - when they could be combating it. On the other hand, splitting-only trees are simpler than partially-reticulated ones - and this simplification is often a permissible one.

References

• Tyler, Tim (2011) Phylomemetics
• Tyler, Tim (2013) On Lewontin's Principles