Analysis of the Ectocarpus genome failed to detect homologues of many of the enzymes that are known, from other organisms, to have roles in alginate biosynthesis and in the remodelling of alginates, fucans and cellulose, indicating that brown algae have independently evolved enzymes to carry out many of these processes.
For example there are several additional membrane-localized proteins of interest, including three integrin related proteins. Integrins have an important role in cell adhesion in animals but integrin genes are absent from all the previously sequenced stramenopile genomes. The Ectocarpus genome also encodes a large number of ion channels, compared to other stramenopile genomes. These include several channels that are likely to be involved in calcium signalling such as an inositol triphosphate/ ryanodine type receptor (IP3R/RyR), four 4-domain voltage-gated calcium channels, and an expanded family of 18 transient receptor potential channels. Members of all these classes are found in animal genomes but are absent from the genomes of land plants. No IP3R genes have been identified in the sequenced diatom and oomycete genomes, but the presence of an IP3R in Ectocarpus is consistent with the demonstration of ‘animal-like’ fast calcium waves and inositolphosphate-induced calcium release in embryos of the brown alga Fucus serratus.
In all E. siliculosus has close to ten thousand ORFans, something evolutionary theory predicted did not exist. But beyond these massive differences between cousins, The E. siliculosus genome further elucidates evolution’s tale of multicellularity.
Instead of the expectation that multicellularity arose once and then proliferated, evolutionists now must say it arose independently several times. And instead of a sort of primitive multicellularity emerging and then undergoing evolutionary refinement, we must believe evolution first produced profoundly unlikely molecular machines, which then in turn enabled multicellularity.
Animal tyrosine and green plant serine/threonine receptor kinases form two separate monophyletic clades, indicating that these two families evolved independently, and in both lineages the emergence of receptor kinases is thought to have been a key event in the evolution of multicellularity. The Ectocarpus receptor kinases also form a monophyletic clade, discrete from those of animal and green plant receptor kinases, indicating that the brown algal family also evolved independently.
In other words, evolution just happened to evolve intricate machines that then were crucial in evolving a major new innovation—multicellularity. I guess we’re living in the right multiverse.