Should we revise evolution theories for the microbes that form so much of an “animal”?
Does the interaction between individual animal and microbes form something greater the sum of each, considered separately? Vital functions like digestion and immunity were long assumed to be under the purview of individual organisms, as capabilities developed and were refined through evolution by natural selection — the differential survival and reproduction of individuals. But if our bodies are less an autocracy of identical cells and more a coalition of multitudes, how can we explain their evolution? Some biologists are calling for a radical upgrade of evolutionary theory, arguing that prevailing ideas, developed from the study of bigger, more easily understood organisms, don’t fit nicely into this new world. Others contend that existing theory just needs to be applied more carefully. Read More ›