Is evolution falsifiable?

Most scientific theories produce predictions which can be tested. This means that if the theory is wrong it can be proved wrong and hence falsified. But for a long time I've wondered whether evolutionary theory can ever produce predictions that can be proven or disproven.

For example, evolution predicts the requirement to acquire food efficeintly. It predicts that competition is so fierce that nothing will be wasted in the struggle to survive. So when it comes to organs this would suggest that no animal would waste any resources on needless vestigial organs that prevent digestion of food. Yet there are not only vestigial organs like the appendix, but also organs like the spleen that seem to have no necessary function. Yet an evolutionist will postulate some imagined explanation. Perhaps these organs have a vital role that we have not discovered yet. Perhaps there is some developmental necessity that produces them or indeed maybe the genes required to get rid of them have not yet mutated.

Our spleen can be removed with no damaging effects it seems, but a ruptured spleen is serious. And as for the appendix, why has this not been selected out of existence? Here is a vestigial organ that can cause infection and death. One would surmise that it would provide significant selective advantage to those individuals that did not have it. Their genes would be passed on far more. Why does it persist? How can this be explained evolutionarily? What function does it perform that leads to the survival of the individual? It seems like this is a challenge to evolution by natural selection. But no, for vestigial organs are explained away by evolutionary story telling, a non falsifiable theory. They must have some benefit, even though we do not know what it is and could measure statistically the disadvantage of their existence.

What has happened to measurement? What has happened to hard facts? How many people die due to the risks associated with having an appendix? And what of the spleen? How much benefit would these organs have to give to an individual to outweigh the risks of possessing them? But then these measurements would enable us to falsify the theory of evolution by natural selection - if we test the hypothesis. For evolution to be true no animal can posess any structure for significant periods of time in which benefit is outweighted by cost, but here is a very costly organ, with no benefit that we can discover.


Another example is diving birds - like tachybaptus ruficollis, the little grebe. Diving birds enable us to measure food foraging because we can observe them constantly as they forage on a lake. Obviously the more food an animal gets, the more it can grow, the more offspring it can produce the more successful it is. And of course we can study the success and rate of foraging in diving birds more than any other. But why do diving birds rest so much? A trip to the park is sufficient to prove this. They will spend hours just floating or sleeping.

Of course we may propose theories of rest for recuperation, cell function and the like. But what was interesting to me when I watched diving birds from dawn til dusk was how much time they spent resting, on top of the 12 hours of rest they had at night. Any bird that could rest less would instantly do better, reproduce more and out compete others. So why doesn't it develop such behaviour? Why do so many species seem to spend so much time doing very little? What survival advantage does this have. Now of course we can propose that it does have survival advantage. But can we measure it? Can we show that the reproductive effectiveness of this bird increases because it rests? Or maybe it has the lazy gene that is linked to the gene for good diving and so good divers have also to be a bit lazy, but this is too difficult to prove so we just assume it's true.

A similar question exists when it comes to black plants, of which there are many species. They harvest far more light because they do not allow any of it to pass through their leaves. So why has there not been the evolution of black plants? They would very quickly out compete the green leafed varieties because they would grow faster, produce more seed and gradually out compete all other plants. Of course the evolutionary explanation is that there must be some disadvantage to having black leaves, that it is evolutionarily beneficial to, in animal terms, throw away half your food beause otherwise the leaf gets too hot, or loses too much water. But leaves take on the ambient temperature of their surroundings. And in the rainforest there is no shortage of water. But still there be some great evolutionary advantage to being green - like leaves over heating or the like. But where are the experiments that prove this? It appears to be just imagination and story telling. Heads I win, tails you lose. If evidence is produced that challenges the theory, the theory can be used to explain that too. Whatever the question is, the answer is evolution. It appears that evolution becomes such an all encompassing explanation that there can be no null hypothesis, no situation in which we can concieve it could be disproved and so no experiment which could test it significantly. It almost appears unscientific, almost religious.