Some biologists published a study on why they think zebra stripes are not for camouflage, etc. They do not seem to understand evolution quite right.
The winner in evolution transmits all their characteristics to the offspring. But you can't say that the characteristic (e.g. stripes) was the cause of the individual being a winner.
A particular human being might be a survivor in a difficult situation because of their excellent intelligence. They may have a mole on their right chin, or have a hairy back, etc. All these characteristics will be passed on to their progeny; but it is not because of their hairy back or the mole on their right chin that they are a winner.
Or instead of intelligence, it might be just luck; maybe the individual just hid in a cave while the rest of the pack was eaten by a predator. Since this individual now reproduces, all his characteristics will be transmitted to his offspring.
This can be extended to all animals, I chose human being as an example animal, that's all.
The characteristics you see in a species like a zebra are just that; they are not there because somehow that characteristic lead the species to win out.
Even for sexual selection this is the same. The characteristic is not a cause of victory; it is a by product of already being victorious.
The same intelligent human being might be able to get more mates; but the females are not selecting the individual for their mole on the right chin or his hairy back.
Another scientific study claims that some people in a Bajau, Indonesia evolved into having bigger spleens because they dove in water for longer periods. A whole chain of scientific arguments are published to prove this-apparently the bigger spleen holds breath longer etc. etc.. who knows what the real cause of their better survival is? Maybe the ancestor of this tribe survived because he could survive the sun well, and he also happened to have a big spleen, and thenn passed on his bigger spleen to all the progeny, which resulted in all these individuals today having bigger spleens. The common ancestor may have also had a firmer set of hands, so he could hold on to the fish longer, and maybe that was the cause for the survival of the tribe, not the spleen. A dozen other theories can be made up to prove whatever you want to prove and invoke evolution.
At a very fundamental mathematical level, these studies are committing the classic error of "correlation is not causality".
This is a common problem I see in evolution related publications; essentially they do not get the causality right. The causes of why an individual survives are not known; the characteristics you see in an individual are the effects of them being winners.