Molecular phylogeny of Myriapoda provides insights into evolutionary patterns of the mode in post-embryonic development

Abstract

Myriapoda, a subphylum of Arthropoda, comprises four classes, Chilopoda, Diplopoda, Pauropoda, and Symphyla. While recent molecular evidence has shown that Myriapoda is monophyletic, the internal phylogeny, which is pivotal for understanding the evolutionary history of myriapods, remains unresolved. Here we report the results of phylogenetic analyses and estimations of divergence time and ancestral state of myriapods. Phylogenetic analyses were performed based on three nuclear protein-coding genes determined from 19 myriapods representing the four classes (17 orders) and 11 outgroup species. The results revealed that Symphyla whose phylogenetic position has long been debated is the sister lineage to all other myriapods, and that the interordinal relationships within classes were consistent with traditional classifications. Ancestral state estimation based on the tree topology suggests that myriapods evolved from an ancestral state that was characterized by a hemianamorphic mode of post-embryonic development and had a relatively low number of body segments and legs.

Myriapoda

“…Morphological data have traditionally supported the relationship with Chilopoda as sister group of Progoneata and Symphyla sister group of Dignatha (Pauropoda + Diplopoda) (Edgecombe and Giribet 2007 ;Shear and Edgecombe 2010 ). Up to now molecular data had lower support for alternative trees, but recent papers seem to show a stronger support for a basal position of symphylans (Miyazawa et al 2014 ;Rehm et al 2014 ), as shown in Fig. 6.1 , and even a lower support for a sister group relationship between diplopods and chilopods (Miyazawa et al 2014 ).…”

“…Up to now molecular data had lower support for alternative trees, but recent papers seem to show a stronger support for a basal position of symphylans (Miyazawa et al 2014 ;Rehm et al 2014 ), as shown in Fig. 6.1 , and even a lower support for a sister group relationship between diplopods and chilopods (Miyazawa et al 2014 ).…”

Evolutionary Developmental Biology of Invertebrates 3

“…Morphological data have traditionally supported the relationship with Chilopoda as sister group of Progoneata and Symphyla sister group of Dignatha (Pauropoda + Diplopoda) (Edgecombe and Giribet 2007 ;Shear and Edgecombe 2010 ). 6.1 , and even a lower support for a sister group relationship between diplopods and chilopods (Miyazawa et al 2014 ). 6.1 , and even a lower support for a sister group relationship between diplopods and chilopods (Miyazawa et al 2014 ).…”

The embryoid development of Strigamia maritimaand its bearing on post-embryonic segmentation of geophilomorph centipedes

“…[45,46]), longer body with a higher number of segments is a derived character within Myriapoda, expressed by both the Geophilomorpha within Chilopoda and the Helminthomorpha (which includes several kind of 'long' millepedes, like Platydesmidae and Julidae) within Diplopoda. As myriapods are sequentially segmenting arthropods, an increase in the number of segments implies an extension of the segmentation time.…”