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Ancient Sponges may Represent Earth’s Earliest Animal Life,⁣ New​ Research Suggests

Evidence suggests that ancient sponges may be among the first animals to have ⁤evolved on Earth, appearing substantially earlier than most other⁣ multicellular organisms. A recent study, ​focusing on a specific organic compound,‍ strengthens this hypothesis.

Researchers identified a geological stable sterol form, a 30-carbon (C30) sterol – a component of steroid groups including cholesterol – ⁣within ancient rock formations. This sterol is typically found in the cell membranes ⁣of complex organisms. The team connected ⁤this specific sterol to Demosponges, a class of sea sponges, indicating the “chemical fossil” represents traces of early animal life.

“We did not know exactly what this organism ⁣was like at⁣ that‌ time,⁣ but they‌ must have lived in the ocean,​ soft body, and we suspect​ they did not have ⁣a silica frame,” explained roger Summons, professor of geobiology⁢ at MIT’s Department of Earth, Atmospheric and Planetary Sciences, as quoted by IFL⁣ Science.

Sponges, despite their ‌simple appearance, are classified as animals. They are composed of diverse eukaryotic cells performing specialized functions,lack cell walls,and exhibit behaviors like eating,reproduction,and ​responding to their environment. However, they are⁣ relatively simple animals,⁤ lacking organs,⁤ tissues, and complex systems like‌ nervous systems or circulatory systems. Essentially, they are aggregations of​ animal cells.

The emergence of these early ⁣sponges predates⁣ the Cambrian‍ explosion, a period of rapid diversification of complex life forms marked by a sudden appearance of many animal groups ​in the fossil record. Prior to this, life primarily consisted of ‌simpler structures and ​single-celled‌ organisms.

Initial⁤ findings in 2009 suggested C30 sterols could indicate⁣ early animal life, but alternative theories proposed ‌the sterols might⁣ originate from other organisms or geological processes.

This‌ new research bolsters the original claim.​ By analyzing drill cores and rock outcrops from Oman,western India,and Siberia,the team found evidence⁣ linking the sterols strongly ⁢to Demosponges. ‌

“You are not eukaryotes if you don’t​ have a comparable sterol or lipid membrane,” Summons stated.

further, the team synthesized C30 sterols in⁣ a laboratory setting, demonstrating their ‌production using enzymes encoded by Demosponge genes. This combined ‌evidence – analysis of the⁢ rock samples, characteristics of ⁣modern ‌sponges, and laboratory synthesis – ⁣firmly ‌supports‌ the conclusion that the 635-million-year-old rocks contain evidence of ancient animal life.

“This is⁣ a combination of what‌ is in the ‍stone, what is in the sponge,‌ and what you can make in the⁣ chemical laboratory. There are three lines of evidence that support and mutually reinforce each other, showing that this sponge is among the earliest animals on earth,” Summons concluded.

(rns/rns)