"My ancestors ate meat, so it is moral and healthy to continue eating meat."
Numerous hypotheses exist regarding the dietary habits of our ancient ancestors, the impact these foods had on their well-being, and how their diets influenced evolution. Although it is undeniable that early humans consumed various animal sources, it is equally valid to acknowledge that they did not always do so, just as individuals, groups and societies have been thriving on plant-based diets throughout history.
The weight of evidence suggests that for most of primate evolution insects and fruit have actually been the dominant source of calories. Apes are thought to have excellent colour vision, which is unusual in mammals, so that we can determine the ripeness of fruit.
Even if we possessed comprehensive knowledge of the dietary habits of all our early ancestors throughout the entire course of our evolutionary history, it would still be illogical to infer that we should continue consuming meat simply because some of them did so. In reality, extensive medical research has consistently shown that the consumption of animal flesh and products is detrimental to our health. What is far more likely is that eating animals was largely done when neccessary/easy to survive to reproductive age, an analogy is drinking filthy water to survive dehydration being a terrible strategy to thrive when clean water is available.
Furthermore, this justification for eating meat overlooks a crucial ethical aspect – the fact that historical practices do not automatically justify present actions. Our ancestors engaged in various behaviors that we now consider problematic and they should not be the moral guides to the future of our species.