A lack of sex held back life's diversity for millions of years, fossil study finds
Phys.org • • science
Key Points:
- Researchers from the University of Cambridge found that Earth's earliest animals reproduced asexually, which limited competition and slowed evolutionary diversity for millions of years during the Ediacaran period (635-539 million years ago).
- Using fossils from 574 million years ago and advanced techniques like laser scanning, spatial analysis, and AI, the team showed that asexual reproduction via stolons restricted dispersal and species diversity.
- The shift from asexual to sexual reproduction, driven by increased environmental stress and competition as life moved to shallower waters, led to greater dispersal distances and a rapid burst in evolutionary diversity.
- This study helps explain why early animal life remained relatively unchanged for millions of years before a second wave of diversification accelerated evolutionary progress during the Cambrian period.
- The findings highlight how stress and competition have been crucial drivers of evolution, with sexual reproduction enabling animals to adapt and diversify more effectively in challenging environments.