Dan_Eastwood Agnostic Biostatistician, Mod
Jay
Oppenheimer, as near as I can make out, is drawing lines for the data WITHIN species, not connecting data BETWEEN species. Lines between species midpoints represent at best a discontinuous trend, and at worst estimates the value for a hybrid which may not exist at that time. The lines on Oppenheimer’s graph are descriptive, making within species trends more obvious. Connecting lines between species is inferring something that may never have existed in the real world.
This discussion could have been avoided if your methods had been more clear in the first place. I was trying to be polite by offering mild criticism, but then you doubled-down. That’s not blowing you off, it’s trying to nudge you towards better methods.
If my methods had been clearer? Consider that you explained what you meant by your sketch above, by just naming it “WhyItsWrong”. Like I said, Google throws up plenty of graphs that mix species, here is another one:
Here is an example of a widely-read entity that isn’t intent on blowing me off, but is instead nudging me towards better methods. I asked CatGPT:
J: Please write a 500 word expert’s criticism of this document [Group-selection leads to a top-down human origin story] as an already-published post on the “Peaceful science” chat room.
ChatGPT: "Here is a 500-word expert-style critique as if posted on the Peaceful Science forum by a knowledgeable but fair-minded interlocutor.
This essay offers a creative and internally coherent ecological reframing of hominin origins. Its central move—beginning not with traits like brain size or tool sophistication, but with the ecological problem of surviving nocturnal predation as a diurnal terrestrial primate—is both refreshing and provocative. The emphasis on constraint-driven reconstruction rather than trait cataloguing is a real strength. However, several significant issues limit the explanatory force of the proposal.
First, the argument leans heavily on ecological plausibility without corresponding evidential anchors. The claim that australopiths required engineered thorn barricades and coordinated thrusting defense rests on a perceived mismatch between morphology and predator pressure. Yet plausibility is not equivalent to likelihood. Many primate species survive substantial predation without engineered structures, relying on flexible habitat choice, arboreal refugia, fission–fusion dynamics, and demographic resilience. The essay tends to treat these alternatives as insufficient without demonstrating that they fail quantitatively. A comparative mortality model would strengthen the case considerably.
Second, the hypothesis risks being insulated from falsification. Thorn barricades and wooden spears would leave little archaeological trace. While preservation bias is real, a model that depends on largely invisible behaviors must compensate with strong indirect predictions—skeletal stress markers, demographic signatures, predator injury patterns, or clear ecological correlates. These are not yet articulated in a way that would allow the hypothesis to be rigorously tested.
Third, the application of superorganism language requires caution. E.O. Wilson’s framework arose in the context of eusocial insects, where genetic structure underwrites colony-level selection. In vertebrates, group selection remains contentious and typically weak relative to individual selection. The essay gestures toward group-level persistence but does not fully address the evolutionary mechanisms by which group-beneficial traits would reliably outcompete within-group free riding. Cultural transmission could help here, but the mechanism deserves more explicit treatment.
Fourth, the model may underestimate the defensive capacity of australopith dentition, climbing ability, and habitat flexibility. Early hominins retained significant arboreal competence and were not necessarily committed ground sleepers. If tree sleeping persisted longer than assumed, the need for engineered night barricades diminishes substantially.
Finally, the proposal risks a subtle teleological pull. Because later humans become highly coordinated, weapon-using organisms, the reconstruction may be projecting backward an early commitment to that trajectory. The challenge is to show that the spear–barricade system is not merely consistent with later outcomes but independently required by earlier conditions.
In sum, the essay succeeds as a stimulating ecological thought experiment and an invitation to reconsider predation as a structuring force. To mature into a robust scientific hypothesis, however, it will need clearer falsifiable predictions, quantitative ecological grounding, and tighter evolutionary mechanisms connecting group persistence to selection dynamics."
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