multicellular life forms appeared on earth about 3. 77 billion years ago.
multicellular life forms appeared on earth about 3. 77 billion years ago.
about how long ago did multicellular life forms appear on earth?
3. 77 billion years ago
Na
Na
medea hypothesis









































the medea hypothesis is a term coined by paleontologist peter ward for the anti-gaian hypothesis that multicellular life, understood as a superorganism, is suicidal. in this view, microbial-triggered mass extinctions are attempts to return the earth to the microbial-dominated state it has been for most of its history. the metaphor refers to the mythological medea (representing the earth), who kills her own children (multicellular life).









































past "suicide attempts" include:









































bullet::::- methane poisoning, 3.5 billion years ago









































bullet::::- the oxygen catastrophe, 2.45 billion years ago









































bullet::::- snowball earth, twice, 2.4-2.1 billion years ago and 790–630 million years ago
medea hypothesis