qnli question: Analysis of what genome has emphasised the importance of sponges, placozoans, and choanoflagellates  in explaining the arrival of 1500 ancestral genes unique to the Eumetazoa? sentence: This was facilitated by the severely reduced state of their genomes, but as many genes, introns, and linkages lost, these ecdysozoans can teach us little about the origins of animals in general.