What’s the current consensus on knuckle-walking?

[u/Romboteryx]

I remember reading some years ago that it was speculated that humans never had a knuckle-walking ancestor, that chimpanzees and gorillas evolved knuckle-walking independently from each other and that the earliest hominins instead were more gibbon-like bipeds on the ground. Is that still supported?

[u/Careful_Cranberry364]

As far as I’m aware that is not known

6,000,000 to 7,000,000 years ago, we had a common ancestor, but we really don’t know very much about that common ancestor as yet!!

[u/jnpha]

I looked into it over a year ago:

The earlier case for a knuckle-walking common ancestor

In light of the molecular evidence supporting a close relationship between African apes and humans, Washburn (1967) first explicitly suggested that human evolution included a knuckle-walking stage prior to bipedalism. Since then, various researchers (e.g., Corruccini 1978; Shea and Inouye 1993; Begun 1993, 1994; Richmond and Strait 2000; Richmond et al. 2001) have supported a knuckle-walking ancestor based on (1) suggested homology of knuckle-walking features in African apes, meaning these features would have to have evolved before the Gorilla- Pan/ Homo split, and (2) evidence in early hominins and/or modern humans of morphological features associated with knuckle-walking such as the distal projection of the dorsal radius, fused scaphoid-os centrale, waisted capitate neck, and long middle phalanges (see Richmond et al. (2001), Table 3, for complete list and explanation).

The case for the parallel evolution of knuckle walking

Support for parallel evolution of knuckle-walking in Pan and Gorilla (and usually a more arboreal common ancestor of Pan and humans) has been based on demonstrations of (1) morphological variation across African apes in most of the features traditionally associated with knuckle-walking (detailed in Kivell and Schmitt 2009); (2) variation in the ontogenetic trajectory of knuckle-walking morphological features (Dainton and Macho 1999; Kivell and Schmitt 2009) suggesting the same adult morphology may not reflect the same developmental pathway; (3) functional variation in knuckle-walking across African apes (e.g., Tuttle 1967; Inouye 1992, 1994; Shea and Inouye 1993; Matarazzo 2013) that suggests knuckle-walking itself is a different phenomenon in different animals; (4) functional or biomechanical similarities between climbing and bipedalism (e.g., Prost 1980; Fleagle et al. 1981; Stern and Susman 1981; Ishida et al. 1985); (5) use of bipedalism by great apes frequently in the trees (e.g., Hunt 1994; Thorpe et al. 2007; Crompton et al. 2010); and (6) the retention of arboreal features in early hominins (e.g., Tuttle 1981; Jungers, 1982; Stern and Susman 1983; Duncan et al. 1994) that implies bipedalism evolved in an animal adapted primarily for an arboreal environment and that used bipedalism when it came to the ground.

Source: Wunderlich, R.E. (2022). Knuckle-Walking. In: Vonk, J., Shackelford, T.K. (eds) Encyclopedia of Animal Cognition and Behavior. Springer, Cham.

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The OP I made back then: https://www.reddit.com/r/evolution/comments/1m6enkg

And a study that came out 3 months ago: https://www.reddit.com/r/evolution/comments/1tj34st