Sea sponge was the first critter on earth

Scientists from MIT have found new evidence suggesting that the sea sponge was likely the first animal to emerge in the history of life on earth, Discovery News reported.

Discovery News said that MIT researchers performed a genetic analysis on 640-million-year-old rocks and found a molecule hailing from the lowly sea sponge.

Based on this, scientists believe this critter was probably the earth's first animal.

The discovery marks the oldest molecular evidence of animal life ever found. A molecule discovered in rock samples more than 640 million years old has been linked to the sea sponge by researchers at the Massachusetts Institute of Technology. This is almost 100 million years before the Cambrian Explosion, the period of time where most animals we know today began to emerge.

The study which was led by David Gold and Roger Summons of MIT published in the journal Proceedings of the National Academy of Sciences.

The idea that sea sponges were the first animals on earth is not new.

Sponges are animals of the phylum Porifera. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells.

Sponges have unspecialized cells that can transform into other types and that often migrate between the main cell layers and the mesohyl in the process.

Sponges do not have nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes.