Archaean cell wall don't have peptidoglycan, yet they may have <em>, polysaccharides, glycoproteins, or protein-based cell dividers </em>
Bacterial cell walls are made of peptidoglycan (likewise called murein), which is produced using polysaccharide chains cross-connected by abnormal peptides containing D-amino acids
It is a type of reproductive barrier that can lead to speciation. Behavioral behavior, such as mating rituals as in when two populations of the same species show some difference in behavior, typically in mating rituals
