What were the first animals? The fierce sponge–jelly battle that just won't end
2 days ago
- #genomics
- #evolution
- #zoology
- Debate over whether sponges or comb jellies were the first animal lineage has persisted for nearly 20 years.
- Initial evidence favored sponges due to their simplicity, but a 2008 genomic study suggested comb jellies might be first.
- The debate has led to entrenched positions, with some researchers advocating for a more collaborative approach.
- Sponges lack specialized tissues like nerves and muscles, traits thought to have evolved later, supporting their early emergence.
- Comb jellies possess complex features like nerves and muscles, raising questions about how complexity evolved if they came first.
- The challenge lies in distinguishing genetic signals from ancient evolutionary events, complicated by rapid evolutionary changes.
- Different scientific disciplines tend to favor different hypotheses, with zoologists often supporting sponges and genomicists favoring comb jellies.
- Researchers emphasize the need for innovative approaches to resolve the debate and understand early animal evolution.