We are aware of the large and small. We can, for example, taste and smell the earthy but invisible Streptomyces coelicolor. This soil-dwelling bacterium might have been in the first rock on Earth. Some estimates mention a time that was almost 3.8 billion years ago.
Here is the Streptomyces coelicolor chromosome as it was mapped by S. D. Bentley et al. in 2002.