The anole talks at the 2013 Herp Meetings have focused on speciation, hybridization, and systematics. Dr. Gunther Köhler of the Senckenberg Museum in Germany presented his talk on anole genital diversity on Saturday.
Slide from Gunther’s talk, demonstrating striking differences in hemipenial morphologies in sister species pairs.
Genital morphology in anoles is an understudied yet promising area of research. Although hemipenial morphology is a good indicator of phylogenetic relationships in other squamates, anoles are a different case. There is a massive range of diversity in hemipenis size, shape, and ornamentation within Anolis. Unexpectedly, closely related species pairs have very differently shaped hemipenes, despite their external morphological similarities. This suggests that changes in genital morphology evolve very quickly in Anolis.
Along contact zones of closely related species, individuals with intermediate hemipenial morphologies are found. This result is confirmed by looking at hemipenial morphologies of hybrids produced in the laboratory. Not only does hybridization occur, but this phenomenon raises the question of functional neutrality for anole genital morphology. Does having the “wrong” hemipenis shape matter for reproductive success?
There is a strong correlation between female cloacal morphology and male hemipenis morphology, which would suggest that shape does, indeed, matter. However, there is no evidence of reinforcement along contact zones in the mainland. Differences in hemipenial morphology does not prevent hybridization, indicating that a “key-lock” mechanism is not operating in anoles.
As Gunther says, there are more questions than answers when it comes to this phenomenon. There are many potential projects for investigating the genetics of genital morphology of both sexes, as well as the role genital morphology plays in speciation, if any. I am excited to see if answers to these questions develop in the future.
Dr. Gunther Köhler at the 2013 Herp Meetings.
- 2013 Herp Meetings: Does Shape Matter? - July 17, 2013
- Anole Posters at 2013 Herp Meeting - July 15, 2013
- Herp Meetings 2013 Day 1: Reproductive Isolation In Parapatric Subspecies Pairs - July 14, 2013
Rich Glor
Looks like interesting new work, I’m looking forward to learning more. I wonder if differences in hemipenis morphology might contribute to the reproductive isolation that Anthony Geneva has been finding in A. distichus.