New research on the evolutionary genetics of fungi reveals that the compound that makes some mushrooms ‘magic’ may have evolved as a defensive mechanism to discourage invertebrates from eating them.
Psilocybin occurs in a diverse group of fungi, with genetic analysis indicating that it may have evolved several times. This led a group of researchers from the Ohio State University in the US to suspect that a mechanism known as horizontal gene transfer may be occurring.
Horizontal gene transfer involves the movement of genetic material between species, carried by mobile cells such as bacteriophages. It is a process associated with stressful environments, and is rare in complex multicellular organisms.
Researchers found that distantly related fungi in dung and decaying-wood niches showed less variation in their genome content than close relatives in alternative niches. This suggest that the genomes are shaped in part by shared ecological pressures.
It appears that the biological niche of the psilocybin-containing mushrooms provides a clue. In humans, psilocybin causes profound altered states of consciousness and other symptoms such as increased heart rate and dilated pupils.
Read more at Cosmos Magazine