PT  - JOURNAL ARTICLE
AU  - Fumihiro Ito
AU  - Tomotaka Matsumoto
AU  - Tatsumi Hirata
TI  - Frequent Non-random Shifts in the Temporal Sequence of Developmental Landmark Events during Fish Evolutionary Diversification
AID  - 10.1101/239954
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 239954
4099  - http://biorxiv.org/content/early/2017/12/26/239954.short
4100  - http://biorxiv.org/content/early/2017/12/26/239954.full
AB  - Morphology is a consequence of sequentially occurring developmental events, termed a developmental sequence, and evolutionary changes in the sequence can generate morphological diversities. In this study, we examined evolutionary dynamics of the developmental sequence at a macro-evolutionary scale using the teleost fish. From the previous literature describing development of 31 fish species, we extracted the developmental sequences of 20 landmark events involving the whole body plan, and by using them, reconstructed ancestral developmental sequences. The phylogenetic comparisons of these sequences revealed event-dependent heterogeneity in the frequency of changing the sequences. We then determined potential event shifts that can parsimoniously explain the sequence changes on each node of the fish phylogenetic tree. These “heterochronic shifts” are widely distributed on almost of all the branches across the fish phylogeny. The simulation-based analysis indicated that this distribution of heterochronic shifts is not the result of random accumulation over phylogenetic time, but exhibits a curious constant trend so that individual phylogenetic branches harbor similar numbers of heterochronic shifts regardless of length. It is of great interest to know how these findings are related to morphological divergence in animals during evolution.