Final answer:
Multicellular life evolved during the Proterozoic Eon, with the first multicellular organisms emerging about 1 billion years ago from colonies of specialized cells. Notable multicellular life began around 600 to 700 million years ago with the Ediacaran biota. The Cambrian explosion followed the Precambrian Extinction at the end of the Precambrian around 544 million years ago.
Step-by-step explanation:
Multicellular life evolved during the Proterozoic Eon, which spanned from 2.5 billion years ago to about 541 million years ago. By approximately 1 billion years ago, the first multicellular organisms had begun to emerge from colonies of specialized cells. These organisms evolved to the point where they could no longer survive independently but formed more complex structures capable of greater efficiency and functionality.
One notable period in the Proterozoic Eon was marked by the presence of the Ediacaran biota, around 600 to 700 million years ago. The Ediacaran organisms were the earliest known complex multicellular life forms, setting the stage for future evolutionary developments. This era preceded the Cambrian explosion, which occurred around 541 million years ago, leading to a significant diversification of life forms.
It's important to note that multicellular life evolved after a significant event known as the Precambrian Extinction, which occurred at the end of the Precambrian around 544 million years ago. This mass extinction event was followed by the Cambrian explosion, during which many new and diverse life forms appeared, marking a rapid evolution of multicellular organisms.