Biology Reference
In-Depth Information
Concerning the pollination type, optimization of character evolution suggest-
ed that the last common ancestor of the family was pollinated by 'Beetle' (Figure
1B), according to outgroup comparison with other Alismatales [17]. From this
condition, the other types of pollination each evolved several times within the
family. In particular, fly pollination is clearly derived from beetle pollination in
Aroideae, where it evolved in several unrelated genera and is synapomorphic for
the Arisaemateae+Areae clade (indicated by a red arrow in Figure 1).
After the transformation of the coding from multistate to binary characters
(Figure 2), we sought to test a correlation between pollen ornamentation and
pollinators using the concentrated-change test [9] and the discrete method [10].
When polymorphic species were removed, both methods found a correlation be-
tween the ornamentation and the pollination (Tables 1 and 2). The Echinulate
type was found as contingent upon Fly pollination (changes towards Echinulate
pollen happened more often in Fly pollinated taxa; Table 1) with the CCT only.
However, with the Discrete method, the flow diagram showed that transitions
towards Fly pollination were probably followed by transitions towards Echinulate
ornamentation (Figure 3).
When polymorphic species were duplicated, a correlation was found between
ornamentation and pollination only using the CCT. With the coding 'Echinulate'
ornamentation and 'Fly' pollination, the correlation was significant when the or-
namentation was considered as dependent of the pollinator (Table 2).
Figure 2.
Evolution of ornamentation and pollination in Araceae with polymorphic species removed.
A. Optimization
of ornamentation type coded as 'Other-O' (white) and 'Psilate/Verrucate' (black). B.
Optimization of pollination type coded as 'Other-P' (white) and 'Beetle' (black). The bicoloured branches
indicate an equivocal inference of the ancestral character state. The transitions towards 'Beetle' pollination and
'Psilate/Verrucate' ornamentation are indicated by full crossbars and the reversals towards 'Other-P' pollination
and 'Other-O' ornamentation are indicated by open crossbars (red and blue crossbars correspond respectively
to ACCTRAN and DELTRAN optimizations). Species names are coloured according to the subfamilies
(Orontioideae in pink, Monsteroideae in blue, Lasioideae in orange, Calloideae in green and Aroideae in red).
