Did humans really 'lose' biological functions through evolution?

What did @celesttv1 actually say?

The creator ran through a list of human anatomical features supposedly lost through evolution: a penile bone (baculum), a tail, a forearm muscle called the palmaris longus, functional ear muscles, wisdom teeth, and the appendix. The core argument is that upright walking triggered a cascade of losses, and that "humans evolved by dropping old parts that no longer fit our new lifestyle." Most of this is grounded in real evolutionary biology, but the explanations for why certain structures disappeared are compressed in ways that trade accuracy for a cleaner story.

The video framed these losses as straightforward adaptations, which is partially true. But evolutionary biology rarely works that cleanly, and a few of the specific mechanisms cited here are either outdated or oversimplified.

Does the science back this up?

Mostly yes, with important caveats. The baculum claim is the most well-supported. A 2016 study by Brindle and Opie published in PNAS confirmed that the human lineage lost the baculum, and their analysis linked its disappearance to longer copulation duration as a signal of male fitness, not just upright walking. The tail reduction is also real, supported by developmental genetics research. The palmaris longus absence test the creator describes is a legitimate clinical observation, present in roughly 14% of people according to data in the Journal of Hand Surgery. Where the video gets shakier is the appendix and wisdom teeth claims.

The appendix has a complex and still-debated function. Research by Laurin et al. (2011) in the Journal of Evolutionary Biology and work by Parker et al. (2007) in the Journal of Theoretical Biology both argue the appendix serves as a reservoir for gut bacteria and may have immunological roles. Calling it simply "faded" misrepresents active scientific debate.

What did they get wrong or right?

The baculum explanation needs correction. "Once our ancestors began walking upright, that bone became a problem" is a popular claim but not the primary explanation in current literature. Brindle and Opie's 2016 PNAS analysis points to monogamy and extended copulation time as the main drivers of baculum loss in hominins, not locomotion-related injury risk. The walking hypothesis is speculative and not well-supported by the fossil or comparative evidence.

The appendix claim is the clearest factual error. Calling it a structure that "faded because cooked food made digestion much easier" ignores substantial evidence that the appendix retains functional roles. Parker et al. (2007) proposed the safe-house hypothesis, suggesting it harbors beneficial gut microbiota after illness. This does not mean the appendix is essential, but saying it simply disappeared because of dietary change is inaccurate.

On the plus side, the palmaris longus demonstration is accurate and surprisingly good science communication. The ear muscle point is also correct. A 2021 study by Schreiber et al. in Current Biology identified vestigial auricular muscle activity in humans, confirming we retained the neural wiring but lost most functional control.

What should you actually know?

Vestigial structures are genuinely interesting, but the "we evolved to lose it" framing often obscures that evolution does not have goals or directions. Structures that become metabolically costly without providing benefit may be selected against, but many persist simply because there is no strong pressure to eliminate them. The appendix, for example, has persisted across 533 million years of evolutionary history according to Smith et al. (2017) in Comptes Rendus Palevol, which itself argues against it being purely vestigial.

For anyone interested in human optimization, longevity, or peptide-based recovery protocols, this evolutionary framing matters. The body does not shed structures on a tidy schedule, and assuming a biological system is vestigial before the research is settled has a poor track record. The appendix immune function argument is one example. Understanding which systems are actually redundant versus which are poorly understood is worth the extra reading.

• The baculum loss in humans is real and well-documented.
• The evolutionary explanation offered for its loss oversimplifies current research.
• The appendix is not simply a vestigial organ by current scientific consensus.
• The palmaris longus test the creator describes is clinically accurate.
• Vestigial does not mean nonfunctional, and the distinction matters in biology and medicine.