Fingernail tears explained in New Scientist , 7 Feb 2004, p19 as self-confessed nail biter Roland Ennos of the (University of Manchester UK), noticed that normal nails always split across the nail rather than vertically down towards the base. Ennos and some colleagues studied torn and cut nails with a scanning electron microscope and found that nails consist of three layers of keratin fibres. Top and bottom layers consist of randomly arranged fibres, which give the nails flexibility. The middle layer consists of fibres running parallel to the “half-moon” at the base of the nail. This prevents breaks and tears running downwards splits which would be painful and take a long time grow out. The three layer structure is very strong. Ennos commented: The energy needed to cut through nails is as much as what’s needed for horses’ hooves. New Scientist also comments only primates evolved finger and toenails, probably to provide better grip on tree trunks and branches.
Editorial Comment: To say that nails evolved for gripping tree branches is a typical evolutionary non-explanation of how a living creature acquired a particular characteristic. Nails certainly do help primates and humans grip things but that does not explain how they came to have nails. Monkeys, from whom primates are supposed to have evolved, are very good at gripping tree branches, as are birds, squirrels, tree kangaroos and other non-primates that live in trees.
Like many living structures, nails again prove it is the organisation of components that enables a structure to function well, not just the substances they are made from. Organisation is the application of information to matter – something that can only happen when there is a mind on the job, i.e. a creator at work, not chance random processes.(Ref. fingernails, keratin, primates)