Linked from
The 16 pages that link to Secondary endosymbiosis, each with the reason it gives.
PlastidRelated: Many algal plastids spread through later transfers between eukaryotes.
EuglenidRelated: Euglenid chloroplasts descend from an engulfed green alga.
AlveolataRelated: This process explains complex plastids in some alveolate groups.
EuglenaRelated: Euglenid plastids are understood to have arisen through this process.
ChromistaRelated: It explains plastid features shared by several groups once placed in Chromista.
CryptomonadRelated: It explains the complex ancestry of many cryptomonad chloroplasts.