BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY: Unraveling the dynamics of rapid species diversification in Cymot
 hoe butterflies - Robin van Velzen - Wageningen University\, The Netherlan
 ds
DTSTART:20120313T160000Z
DTEND:20120313T170000Z
UID:TALK34911@talks.cam.ac.uk
CONTACT:Oskar Brattstrom
DESCRIPTION:Colonisation of novel host plants can promote diversification 
 in butterflies because they enter new adaptive zones. African sister gener
 a _Harma_ and _Cymothoe_ (Nymphalidae) contrast in species diversification
 : _Harma_ is monospecific and _Cymothoe_ comprises 74 species. They also c
 ontrast in diversity of host use: _Harma_ larvae feed on Achariaceae only 
 while some Cymothoe species feed on the same Achariaceae species while oth
 ers are highly specialised on species of _Rinorea_ (Violaceae). Our aim wa
 s to assess association of host plant use and increased species diversific
 ation _Cymothoe_. I present the first molecular phylogenetic tree of _Harm
 a_ and _Cymothoe_\, based on 53 species (65%) and multiple independent gen
 etic markers within an absolute-time framework. Patterns of diversificatio
 n and host plant use based on full species sampling were analysed using Ba
 yesian and Likelihood methods. Results confirm that _Harma_ and _Cymothoe_
  are sisters on a branch spanning approximately 30my. Net diversification 
 is low during the first 20my (Oligocene and Miocene) followed by a sharp i
 ncrease coinciding with the origination of _Cymothoe_ in the late Miocene.
  A slight but insignificant increase in the rate of diversification after 
 colonisation of _Rinorea_ host plants does not explain this pattern. Gradu
 al decrease in global temperatures after the Miocene promoting habitat fra
 gmentation and reproductive isolation in _Cymothoe_ and their hosts can pr
 ovide an alternative explanation.
LOCATION:Part II Lecture Theatre\, Department of Zoology
END:VEVENT
END:VCALENDAR