Multiverse as an explanatory hypothesis
One of the physicists’ attempts to explain the quantum state wave, which represents a probability distribution to find the particle upon measurement, as a purely material phenomenon is the multiverse hypothesis. According to this hypothesis, every possibility that the state function provides is physically realized by splitting the current universe into all those possible variations, meaning materializations of new universes. This of course means an almost infinite proliferation of possible universes. Someone in such a split-off universe will experience only one realized outcome and simply does not perceive all those other universes with all those other possible outcomes. That person, incidentally, has also been split off into all those possible physical universes. So every micromoment there are countless copies made of the observer, which is you. This then solves the question of where all those possible materializations exist, namely in those other universes that are no longer observable. That you find an electron with a spin up in your measuring instrument means that your universe has also been split off in one where the electron spin points down.
A better thought out variant of the above is the assumption that all those possible universes already exist and no new ones are necessary. One proponent is Sean Caroll. Caroll says that the quantum state wave of the universe never collapses. His idea comes very near to the ideas of Julian Barbour and his Platonia.
Photosynthesis efficiency
The multiverse hypothesis has considerable support among physicists. However, the results of quantum biology contradict it. Look for example at chlorophyll photosynthesis which in 99% of its activities always chooses the shortest path for the excited electron (exciton) so that its energy can be used in the chlorophyll reaction center. According to the multiverse hypothesis, 99% of the split-off universes in each chlorophyll cell must now show a less efficient path to the reaction center. We will therefore not see this efficiency in 99.9999999% of the split-off universes.
How then is it possible that we end up consistently in split-off universes where the chlorophyll always functions 99% efficiently? If that were not the case, we would soon end up in universes, split-offs from our current universe then, where the chlorophyll does not do what it clearly always does, convert solar energy efficiently into the living substance of the plant. And it is not only with chlorophyll that we come across that quantum efficiency, almost every process in a living organism shows that remarkable efficiency.
In 99,999999….% of all universes in a multiverse life cannot survive
In short, if the multiverse hypothesis were true, only a very small percentage of the split-off universes would successfully contain living biological systems. Worse still, every universe that contains biological life has an extremely high chance of containing biological life no longer functioning well at the next spin-off.
In other words: that we have lived, live and continue to live is a very strong argument against the multiverse hypothesis.