Biology
The cell inside the cell
How complex cells began, and what a crawling microbe adds to the story.
In a laboratory in Vienna, a microbe a thousand times smaller in volume than a human cell stretches out thin arms, grips the glass, and crawls.
In 2026, a team led by the University of Vienna reported in Nature that these microbes, called Asgard archaea, crawl in a way seen before only in complex cells.
Why does a crawling microbe excite biologists? Because these simple microbes are the closest known relatives of the cells that build every plant, animal and fungus, including you.
To see why, we need the story of how complex cells began.
- 1/1000
- the volume of a human cell, roughly
- 2
- Asgard strains filmed crawling: one grown in Vienna, one in Japan
- Two kinds of cell
- Bacteria living inside cells
- The search for the host
- Arms that crawl
A microbe that crawls
University of Vienna (30 September 2026): Philipp Radler and colleagues in Christa Schleper’s group, with JAMSTEC (Japan), IST Austria and HZI Braunschweig, report in Nature that two Asgard archaea, a Lokiarchaeon cultivated in Vienna and a Heimdallarchaeon cultivated in Japan, attach to surfaces and crawl using dynamic protrusions. Their cells are about 1,000 times smaller in volume than a human cell. The release calls Asgard archaea the closest known microbial relatives of eukaryotes.
This new study is the hook; chapter IV returns to it. The rest of the film is long-established biology.
The 3D scenes are simplified teaching models, not to scale.
Sources: University of Vienna (30 Sep 2026): Unexpected dynamics of ancient microbes discovered (Radler et al., Nature, doi 10.1038/s41586-026-11063-9)
