Evolution is a vital aspect in Pokémon, it is completely necessary to get your Pokémon to be the best that it can be. Normally it is by level up, trading, stones or happiness, however in Ruby & Sapphire, they added a couple of new methods including Pokéblocks and having a spare slot on your team. Well diamond & Pearl are no different, bringing some of the most bizarre means for evolution known. Here are a list of all the new Evolutionary Methods:

Gender Evolution

The first change of note is the addition of Gender Based Evolution. In diamond & Pearl, several Pokémon evolve into their evolution based on Gender. For example Combee only evolves into Vespiquen if its female, and considering that Combee's are 87.5% Male, it is a feat indeed. Below are the Pokémon that evolve and the method they evolve with:

Base No. Pic Base Name Method Final No. Pic Final Name
#412 Burmy Lv. 20 ♀ #413 Wormadam
#412 Burmy Lv. 20 ♂ #414 Mothim
#415 Combee Lv. 21 ♀ #416 Vespiquen

Attached Items & Level Up

A New Concept Discovered is the ability to make a Pokémon hold an item and level it up in order for it to evolve. The Pokémon MUST hold the item in order evolve and some are even time Specific:

Base No. Pic Base Name Method Final No. Pic Final Name
#207 Gligar Razor Fang @ #472 Gliscor
#215 Sneasel Razor Claw @ #461 Weavile
#440 Happiny Oval Stone @ #113 Chansey

Area Based Evolutions

Some Pokémon even evolve based purely on their area, either confined into a very small portion of an area or in an entire route. The Pokémon will only evolve here and thats by simply levelling up your Pokémon a single level. Above is Moss Rock and Ice Rock, no the Ice Rock isnt a bad pic, it's really snowy:

Base No. Pic Base Name Method Final No. Pic Final Name
#082 Magneton Mt. Coronet Range #462 Magnezone
#133 Eevee Moss Rock in Eterna Forest #470 Leafeon
#133 Eevee Ice Rock in Route 217 #471 Glaceon
#299 Nosepass Mt. Coronet Range #476 Probopass

Attack Based Evolutions

A fair few Pokémon evolve simply because they know an attack, an attack that exists in the moveset. Once the Pokémon learns the attack, if you level them up, they should evolve. However if you get rid of the attack before they evolve, they will NOT evolve:

Base No. Pic Base Name Method Final No. Pic Final Name
#108 Lickitung Rollout Known #463 Lickilicky
#114 Tangela AncientPower Known #465 Tangrowth
#190 Aipom Double Attack Known #424 Ambipom
#193 Yanma AncientPower Known #469 Yanmega
#221 Piloswine AncientPower Known #473 Mamoswine
#438 Bonsly Mimic Known #185 Sudowoodo
#439 Mime Jr. Mimic Known #122 Mr. Mime

Other Pokémon Based Evolutions

A one off Pokémon Evolution method is requiring another Pokémon on your team. When you have the Pokémon on your team, the main Pokémon will evolve when it levels up. You will not lose your other Pokémon:

Base No. Pic Base Name Method Final No. Pic Final Name
#458 Mantyke
#223 Remoraid
#226 Mantine

Trade With Items

While it is not a new concept, it utilises new items that you may just simply look at and disregard. Simply attach the items to the Pokémon and trade them with your friends:

Base No. Pic Base Name Method Final No. Pic Final Name
#112 Rhydon Protector #464 Rhyperior
#125 Electabuzz Electrizer #466 Electivire
#126 Magmar Magmarizer #467 Magmortar
#233 Porygon2 Dubious Disc #474 Porygon-Z
#356 Dusclops Reaper Cloth #477 Dusknoir

Stones

Another not new concept, but requiring new items, there are several new stones. These stones will only work on these Pokémon, one of which only works on Pokémon of a certain Gender:

Base No. Pic Base Name Method Final No. Pic Final Name
#176 Togetic Shiny Stone #468 Togekiss
#315 Roselia Shiny Stone #407 Roserade
#198 Murkrow Dusk Stone #430 Honchkrow
#200 Misdreavus Dusk Stone #429 Mismagius
#281 Kirlia ♂ w/ Dawn Stone #475 Gallade
#361 Snorunt ♀ w/ Dawn Stone #478 Froslass

Time Based Happiness

Although not a new concept, it is a concept that was brought back after not really existing for the 3rd Generation. Now many Pokémon have the time based Happiness Evolutions. Some Daytime, Some Night Time:

Base No. Pic Base Name Method Final No. Pic Final Name
#406 Budew Happiness @ #315 Roselia
#433 Chingling Happiness @ #358 Chimecho
#447 Riolu Happiness @ #448 Lucario