A new batch of Pokémon from the Unova region have been added to Pokémon Go, including Axew, Roggenrola, Timburr, and some other strong picks.

A new batch of Pokémon from the Unova region have been added to Pokémon Go, along with the addition of trade evolution.
Roggenrola, Tympole, Dwebble, Trubbish, Karrablast, Joltik, Shelmet, and more Pokémon will be found in the wild. According to Niantics announcement post, Venipede, Dwebble, Roggenrola, Tympole, Trubbish, Karrablast, Joltik, Shelmet, Timburr, Tirtouga, Archen, and Axew will come from eggs, though theres no clarification if this means Axew, Tirtouga, Archen, Venipede, and Timburr wont be spawning in the wild. Timburr will also be obtainable through tier one raids.
With the new trade evolution mechanic, trading Pokémon to evolve them isnt mandatory, but it will lower the candy cost to evolve them. This is huge, as Pokémon like Haunter and Machoke all have a whopping 100-candy cost to evolve into their stronger forms. The Pokémon affected by trade evolution are Haunter, Machoke, Graveler, Kadabra, Boldore, Gurdurr, Karrablast, and Shelmet.
Theres also a new batch of regional-exclusive Pokémon. Eastern hemisphere players will encounter Red-Stripe Form Basculin, with the Western hemisphere players seeing Blue-Striped Form Basculin. Players in Egypt and Greece will see Sigilyph. Folks in the Southern United States, Mexico, Central America, the Caribbean, and South America will see Maractus. Throh will be found in North America, South America, and Africa, with its counterpart, Sawk, being found in Europe, Asia, and Australia.