The problem of pan-African roots

A problem of establishing macrophylic relations in Africa is the existence of common lexical items that are shared between the phyla in ways which do not suggest can they be used as evidence for a genetic connection. This suggests that proposals for large-scale language classification in Africa may be flawed by a failure to consider the transphylic distribution of many roots. The paper gives some examples of such lexical items and canvasses possible explanations;

a. they are ancient loanwords

b. they are convergent because of common phonaesthemes

c. African language phyla really are all related

d. they are retained from an early stage of world language diversification

Some roots seem to have a wider distribution in Eurasia, which suggests that (d) may be relevant in some cases.