Comment Re:It doesn't work that way (Score 1) 323
For example, although about 50% of French and English words derive from a common ancestor (like "mere" and "mother," for example), with English and German the rate is closer to 70%—indicating that while all three languages are related, English and German have a more recent common ancestor.
This ignores historical reality. In England, a Germanic language was spoken before French-speaking people invaded, bringing their Latin-derived and other words with them. The Germanic "ancestry" came first, and a minority of French words were injected more recently.
Words of language do not spread like genes in a population.
No, it's just not the whole story. Historical linguistics pays due attention to all kinds of language contact, including borrowing. Loanwords are not counted as cognates.
Language change and evolution in biology are not exactly similar phenomena, but it's a good analogy. Borrowing can be likened to lateral gene transfer.