In Pokemon GO, players earn Research Breakthroughs by completing daily field research tasks. Every day that a task is completed, progress is made for the Research Breakthrough. After seven days of completed tasks, a Research Breakthrough reward is given. That can be theoretically done four times a month if players complete tasks every day.
The Research Breakthrough rewards typically are some XP bonuses, Stardust, potential items, and then an encounter with a featured Pokemon. In May 2021, the featured Pokemon was Galarian Ponyta. For June 2021, the Research Breakthrough encounter is set to be Clamperl.
When players collect 50 Clamperl candies in Pokemon GO, they can evolve the Pokemon. What it evolves into is randomized between two options: Huntail or Gorebyss. With Pinap Berries, players should come close to evolution based on June 2021 Research Breakthrough rewards.
Raid Pass bonuses for the June 2021 Research Breakthrough rewards
Starting in June 2021, players will earn more than the Pokemon encounter when they complete their Research Breakthrough. Each week that is completed will also reward a free Raid Pass. In theory, that's a total of four passes when every day is completed in June.
On top of the Raid Pass bonus, there will also be an XP bonus. For the month of June and further into the Pokemon GO season, Research Breakthroughs will reward double the normal amount of XP.