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Here, we discuss a more realistic scenario of transition to multicellularity through integration of pre‐existing transient cell types into the body of an early metazoon, which possessed a complex life cycle with a differentiated sedentary filter‐feeding trophic stage and a non‐feeding blastula‐like larva, the synzoospore. Choanoflagellates are considered as forms with secondarily simplified life cycles.</jats:p>","journal":"BioEssays","year":2009,"id":675568,"datarank":4.612537204856302,"base_score":5.176149732573829,"endowment":5.176149732573829,"self_citation_contribution":0.7764224598860744,"citation_network_contribution":3.8361147449702275,"self_endowment_contribution":0.7764224598860744,"citer_contribution":3.8361147449702275,"corpus_percentile":null,"corpus_rank":null,"citation_count":176,"citer_count":143,"citers_with_citation_signal":124,"citers_with_endowment":124,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1765135,"name":"Anastasiya V. 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Multicellular stages occurring in the complex life cycles of opisthokont protists (mesomycetozoeans and choanoflagellates) never resemble a blastula. Here, we discuss a more realistic scenario of transition to multicellularity through integration of pre‐existing transient cell types into the body of an early metazoon, which possessed a complex life cycle with a differentiated sedentary filter‐feeding trophic stage and a non‐feeding blastula‐like larva, the synzoospore. 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