Ancient Fossil Reveals Animal-Microbe Partnerships Dating Back 550 Million Years

Topic: Biology

Scientists from Nanjing University found evidence of animal-microbe partnerships in a 550 million-year-old fossil from southern China. This discovery pushes back the earliest known evidence of such relationships by 100 million years.

Imagine that half of the cells inside your body are not human but tiny microbes. These microbes help you digest food, support your immune system, and even help some animals camouflage themselves. But how long have these partnerships between animals and microbes existed? A team of scientists led by Zhenfei Wang and Yongbo Peng from Nanjing University in China has found evidence of such relationships in a 550 million-year-old fossil from southern China.

The researchers analyzed fossils from the Ediacaran period, which was a time when Earth's surface was mostly covered in ice. As the ice melted, oxygen levels were low, and hydrogen sulfide built up to toxic levels in some marine environments. Despite these harsh conditions, early animals thrived. The team focused on the tubular fossil Conotubus, which is one of the rarest fossils from this period.

The scientists used geochemical fingerprints called sulfur and molybdenum isotopes to identify signs of past microbe-animal interactions. Isotopes are like chemical fingerprints that can reveal how biological processes alter specific ratios. By analyzing these isotopes in remarkably well-preserved fossils, the team found evidence of animal-microbe partnerships dating back 550 million years.

This discovery pushes back the earliest known evidence of such relationships by 100 million years. The research was published in the Proceedings of the National Academy of Sciences.

Why It Matters

Understanding how long animal-microbe partnerships have existed can help us better appreciate the importance of these relationships in our own lives and ecosystems.

Key Facts

• A 550 million-year-old fossil from southern China contains evidence of animal-microbe partnerships.
• The discovery pushes back the earliest known evidence of such relationships by 100 million years.
• The researchers used geochemical fingerprints called sulfur and molybdenum isotopes to identify signs of past microbe-animal interactions.
• The Ediacaran period was a time when Earth's surface was mostly covered in ice, but early animals thrived despite harsh conditions.
• The team focused on the tubular fossil Conotubus, which is one of the rarest fossils from this period.

Key Terms

Microbiome

The community of microbes living inside and around an organism.

Isotopes

Atoms with different numbers of neutrons, used as chemical fingerprints to identify biological processes.

Implications

Understanding how long animal-microbe partnerships have existed can help us better appreciate the importance of these relationships in our own lives and ecosystems.