It is difficult to shake up the Brussels bureaucracy, but a consensus is building that next year might offer an opportunity of a kind that only arises once in a decade.
What is more, the need for moral stiffening only arises once we have already decided what morality requires of us here, and the real question was whether that decision needed to be based on principle.
Extinction seems too facile an explanation to account for fact that all complex life on Earth shares a common ancestor that only arose once.
In some of the hypotheses discussed, each individual fusion event benefits the cell; in others, a benefit only arises once sufficiently many mitochondria have fused to form an interconnected network.
The fact that endosymbiosis is strictly necessary to evolve beyond the prokaryotic way of life, but is exceptional (if still documented) in prokaryotes, goes some way to explaining why eukaryotes only arose once in four billion years of evolution.
Why not, but did the eye, that is so complex, arise once only?
While it certainly seems reasonable to expect that a complex organelle may only have arisen once in evolution (meaning acidocalcisomes should be considered ancient), such expectation is not evidence in itself.
When we instead include the baseline DC for each sale prior to the policy change, the problem of capturing only the mechanical effect arises once again.
Therefore, while there are multiple origins of infecting blood-feeding arthropods, the ability to be transmitted from vertebrates back into the arthropod host may have arisen once only, and subsequently been lost in the transitional group after the divergence of R. akari and Rickettsia australis.
Since we think that the homologous similarity of having multiple digits arose once in evolutionary descent, we use it only once, at the level signaling the common ancestry of all tetrapods.
