There are two parts to the origin of eukaryotic cells:
[[Endosymbiosis]]: Theorized by [[Lynn Margulis]], proposes that
mitochondria, along with other eukaryotic organelles, first existed as
independent organisms
[[Endomembrane System]]: Documented by [[Christian de Duve]], the
endomembrane system involves parts of organelles specific to eukaryotic
organelles, such as the nuclear envelope
In eukaryotes, [[mitochondria]] have separate DNA from the nuclear genome,
which is evidence for [[Endosymbiosis]]