Thomas C. G. Bosch

TL;DR: Recent technological and intellectual advances that have changed thinking about five questions about how have bacteria facilitated the origin and evolution of animals; how do animals and bacteria affect each other’s genomes; how does normal animal development depend on bacterial partners; and how is homeostasis maintained between animals and their symbionts are highlighted.

TL;DR: Comparisons of the Hydra genome to the genomes of other animals shed light on the evolution of epithelia, contractile tissues, developmentally regulated transcription factors, the Spemann–Mangold organizer, pluripotency genes and the neuromuscular junction.

TL;DR: Evidence from Hydra is focused on suggesting that taxonomically-restricted genes play a role in the creation of phylum-specific novelties, in the generation of morphological diversity, and in the innate defence system, and it is proposed that taxon-specific genes drive morphological specification, enabling organisms to adapt to changing conditions.

TL;DR: Holobionts and hologenomes are incontrovertible, multipartite entities that result from ecological, evolutionary, and genetic processes at various levels that constitute a wider vocabulary and framework for host biology in light of the microbiome.

TL;DR: Consideration of these patterns of gene distribution underscores the likely significance of gene loss during animal evolution whilst indicating ancient origins for many components of the vertebrate innate immune system.