We know so little about the little ones. Viruses, archaea, and bacteria are far too successful to mark it down to dumb luck. Microbes navigate and adapt to their surroundings. They communicate at the molecular and genetic levels, among themselves and with other species.
“Microbes indulge in a variety of social behaviors involving complex systems of cooperation, communication, and synchronization.” ~ English microbiologist Stuart West
Microbes acclimate themselves to other species: variously accommodating or antagonizing. Through selective genetic exchange, microbes demonstrate what approximates to empathy, and, when times are tough, work for the betterment of their community.
When presented with an abundance of nutrients, single-celled algae bloom into a prolific population. As the food runs out, individuals self-selectively commit suicide to sustain others. The nutrients from self-sacrificing algae can only be used by relatives and inhibit the growth of non-relatives. Not only does suicide help kin, it can also harm competitors.