Vedas do not advocate the theory of evolution. They talk about creation of various species. The theory of evolution is against Vedic Authority. In the Taittiriya Samhita iii.1.1 of Krishna Yajur Veda, it is stated that Prajapati created Serpents, Birds and Human offsprings.
The Dasavatara (10 Avataras of Lord Vishnu) starting with Matsya (Fish), Kurma (Tortoise), Varaha (Boar), Narasimha (Lion-Man) and Vamana (dwarf) is not to be construed as one supporting the Darwin's theory of evolution. All these are divine manifestations of the same Supreme who is reverentially worshipped in the form of Lord Krishna.
Some say that those belonging to Kapi Gothra have originated from Kapi (Monkey). But this is not correct. The term "Kapi" also means Surya (Sun). This has to be kept in view. Hence Kapi Gothra means those who belong to the lineage of the Sun.