Modern-day analogs in Antarctica reveal ponds teeming with life similar to early multicellular organisms.
Modern-day analogs in Antarctica reveal ponds teeming with life similar to early multicellular organisms.
When the Earth froze over, where did life shelter? MIT scientists say one refuge may have been pools of melted ice that dotted the planet’s icy surface.
In a study appearing today in Nature Communications, the researchers report that 635 million to 720 million years ago, during periods known as “Snowball Earth,” when much of the planet was covered in ice, some of our ancient cellular ancestors could have waited things out in meltwater ponds.
The scientists found that eukaryotes — complex cellular lifeforms that eventually evolved into the diverse multicellular life we see today — could have survived the global freeze by living in shallow pools of water. These small, watery oases may have persisted atop relatively shallow ice sheets present in equatorial regions. There, the ice surface could accumulate dark-colored dust and debris from below, which enhanced its ability to melt into pools. At temperatures hovering around 0 degrees Celsius, the resulting meltwater ponds could have served as habitable environments for certain forms of early complex life.
Read more at Massachusetts Institute of Technology
Image: A cyanobacterial mat fragment sampled from the periphery of a meltwater pond. (Credit: Roger Summons)
