Perhaps you should just read the work.
The answers to many of these questions are to be found in Suwa et al, Paleobiological Implications of the
Ardipithecus ramidus Dentition, Science 326, 94 - 99 and in the papers cited in that one. The conclusions of progressive reduction in upper canine size, change in canine morphology, the loss of honing in the CP3 complex which begin with Miocene apes and continue through
Orrorin tungenensis, Sahelanthropus tchandensis, Ar kadabba, the australopithecenes and Homo to modern humans is robustly evidenced. Combining that with observations about timing of canine eruption in
Ar ramidus, extant apes and extant humans, and simultaneous reductions in sexual dimorphism and observations that an enhanced UC is critical to sexual success in
Pan troglodytes and other primates, leads to the reasonable hypothesis that a large UC and honing in CP3 complex (along with sexual dimorphism) are conserved in conditions of physical male-male sexual competition and have been lost in the human lineage by relaxed selection.
Sexual selection does not just mean mate selection as you seem to think, but also (in fact primarily) includes traits deriving from male-male sex-related conflict, as in this case. **And what does this mean? Are you saying the guys with big teeth killed each other off, so that the meek inherited the earth? What? Are you actually suggesting that any male animal is more deadly to other males than are humans? **
Oh, and did you miss the point that
Ar ramidus pre-dates tool use by 2.5 million years? **Prove it. Failure to find obvious tools with the fragments of fossilized bone they found does not prove they didn’t have tools. **
Well there are natural variations within any species in any parameter that you care to measure, and some can be shown to be selected for (for example skin pigmentation) and others represent no more than random drift. But differences become important from an evolutionary point of view when they fall outside the intraspecific range. In the case of the male UC, modern human crown height ranges from 7 to 10mm,
Ar ramidus from 9 to 12mm, in chimpanzee from 13mm to 19mm and in gorilla from 18 to 26mm. Even more significantly the difference between male and female in humans is 4% to 9%, in
Ar ramidus from 10% to 15% and in modern great apes from 19% to 47%.
Well, I don’t think this hypothesis is as simplistic as you represent it if you read the work, but in any case you need to look at the food carrying capabilities of apes, not just any animal. **Leopards can carry a lot more food than we can, and climb trees with it to boot. If food carrying capabilities were important enough to force evolutionary changes, ar ramidus could have found a much more efficient thing into which to develop. **
No, specimens representing about 35 individuals from Aramis, with a minimum of 14 individuals for both upper canine and upper second molar, plus seven individuals from another site.
There is one partial skeleton and a number of fragments. That’s it.
A probable female because of the relative size of UC and post-cranium. ** Could be. Of course, modern forensic pathologists sometimes have trouble when they’re looking at a brand-new skeleton. But I’ll grant it’s probably female in the absence of any reason to believe otherwise. **
What you have shown is that your knowledge of the evidence and conclusions presented in the suite of research papers is wondrously thin. I recommend that you read the actual work before you leap in to criticise it.
No, I propose that you actually prove your proposition, not just tell us to go read something that you feel is more persuasive than you have managed to be.
Alec
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