<Tr> <Td> </Td> <Td> <P> Bennettitales </P> </Td> </Tr> <Tr> <Td> </Td> <Td> <P> Ginkgo </P> </Td> </Tr> <Tr> <Td> </Td> <Td> <Table> <Tr> <Td> </Td> <Td> <P> Gnetales (gymnosperm) </P> </Td> </Tr> <Tr> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> <P> Conifers (gymnosperm) </P> </Td> </Tr> <Tr> <Td> </Td> </Tr> </Table> </Td> </Tr> <Table> <Tr> <Td> </Td> <Td> <P> Gnetales (gymnosperm) </P> </Td> </Tr> <Tr> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> <P> Conifers (gymnosperm) </P> </Td> </Tr> <Tr> <Td> </Td> </Tr> </Table>

Which of the following would need to occur first for life to have evolved on early earth