Scientists study human language evolution via apes
UK-based scientists studied the communication calls of 'Orangutans', one of our closest ancestors. 'Kiss-squeaks' were analysed to understand t, p, k consonants as their sound depends on tongue-lip movement, rather than voice. They found that different signals were sometimes used to carry same information to reinforce a message like humans use 'car, vehicle, automobile' to convey the same meaning.