The debate in the modern scientific community about the evolution of language has more than a century of history (Jastrow, Reference Jastrow1886). However, initially, due to the absence of evidence, highly speculative or unfounded hypotheses were often proposed. This led the Société de Linguistique de Paris to prohibit the study of language evolution in 1866. As Stibbard-Hawkes recalls in his article, the continued absence of evidence was assumed to be evidence of absence of proof regarding the evolution of language. Moreover, the author convincingly argues that modern humans do not always leave evidence of what could be considered modern culture or even advanced technology. Analysis of data from the three cultures (Mbuti, G//ana, and Hadza) seems to suggest this.
Nevertheless, these three Homo sapiens cultures cannot entirely conceal characteristics of their modern cognitive capacity, which are evident in the cultural materials they produce. For example, the Mbuti pattern reproduced in Figure 1 of the present target paper comes from Tanno (Reference Tanno1981), who described the Mbuti cultural materials made by means of plant strings and occasionally duiker skin. Among the many objects and plants described, Tanno detailed the nets for net-hunting, made of Manniophton fulvum strings through a complex process. This process involves making the bast into fibers, then twisting them into two threads, which the Mbuti twist again into a string on their thighs. (Tanno, Reference Tanno1981, pp. 19, 30). The Mbuti make their quivers from duiker skin, wooden bells for the dogs, baskets from Eremospatha haullevilleana strings, and mats from Afaendidia conferta leaves “by doubling them along the midrib and pricking them into each other in succession” (Tanno, Reference Tanno1981, p. 30; see also Fig. 14 on p. 31). Tanno also describes Mbuti clothes, like the “pongo” or barkcloth, also mentioned in Stibbard-Hawkes's target article. These objects feature very special drawing patterns characterized by recursive strings of geometrical, rhomboid figures; however, the original figure includes another drawing that shows a pattern of embedded geometrical objects. Extremely interesting is the “luma,” a set of 12–15 pipes (made from the plant Olyra latifolia) of different lengths that produce various pitches, each played by one man in a coordinated manner, performing melodies and harmonies together.
The ability to manipulate geometric elements and/or create musical structures (which usually contain subordinate structures and elements, such as section, period, phrase, semi-phrase, and motif) requires a cognitive capacity that includes a specific working memory, that of modern H. sapiens (Manrique, Read, & Walker, Reference Manrique, Read and Walker2024). The same can be said of syntactic structures, which can easily embed additional elements and even complex structures.
The syntactic capacity has been addressed from various areas of scientific research, but often encounters the difficulty of providing evidence of a cognitive capacity for which we have no evidence outside of the human mind. If the evidence is scarce but enough, it has sometimes been simply concluded that the presence of modern language is “inevitable” (Dediu & Levinson, Reference Dediu and Levinson2018), or conversely, the stricter viewpoint is criticized for the lack of (more empirical) evidence because it seems that there is never enough evidence.
One must not be dogmatic, as nowadays we have new data from many different sources. Since the publication of the first data on Neanderthal DNA, many theories and viewpoints have had to be reworked. Accepting theories based on pigment residues or marks on the wall (Rodríguez-Vidal et al., Reference Rodríguez-Vidal, d'Errico, Giles Pacheco, Blasco, Rosell, Jennings and Finlayson2014), which can hardly be justified as evidence of the recursion that is evident in nets, baskets, or the diamond pattern from the Blombos Cave, or extremely small remnants of fibers from a possible fabric (Hardy et al., Reference Hardy, Moncel, Kerfant, Lebon, Bellot-Gurlet and Mélard2020), may lead us to ignore data about endocranial ontogeny (Gunz et al., Reference Gunz, Neubauer, Golovanova, Doronichev, Maureille and Hublin2012), or even to dismiss it as irrelevant.
It appears that Neanderthal-Sapiens hybrids (or Denisovan-Sapiens hybrids) were not seen as problematic or detrimental to the archaic H. sapiens species. The evidence of introgressive hybridization is widely accepted and cannot be ignored, as it has very important implications for the concept of species (Scerri et al., Reference Scerri, Thomas, Manica, Gunz, Stock, Stringer and Chikhi2018). However, this is also important regarding cognition and it does not seem to have been emphasized enough in the discussion on language evolution.
The Mbuti people reproduce, using limited means such as painting or fabric, a recursive pattern with rhomboid figures that essentially has no established limit. Precisely, we have clear evidence of this same recursive pattern, such as in remains from 75,000 years ago in the Blombos Cave (South Africa), found in more than one object, ruling out that this pattern emerged by chance (Henshilwood, d'Errico, & Watts, Reference Henshilwood, d'Errico and Watts2009).
If the ability to produce patterns like this is somehow related to the mental capacities of the brain, then it could be that they were already within the reach of H. sapiens, whose brain capacity appears to extend back to 160,000 years ago (Zollikofer et al., Reference Zollikofer, Bienvenu, Beyene, Suwa, Asfaw, White and Ponce de León2022).
All the plant-based products mentioned above are indeed perishable, unless exceptional conditions prevent it. However, there are elements that show a modern cognitive capacity behind them, with the power necessary to produce recursive patterns in drawings, musical pieces, and a multitude of structures made from braided fibers through complex manufacturing processes and the creation of knots and braids.
While it remains controversial and debatable whether other hominins could create the same types of objects as those mentioned above (nets, quivers, baskets, etc.), all present-day humans from all regions of the planet can produce this kind of patterns, and they can also learn any human language. Therefore, we should reflect the true relevance of the impact of genetic inheritance inherited from different species of the Homo genus on a common cognitive capacity in all current populations, which has existed for at least 75,000 years according to archaeological evidence.
The Mbuti people have established a connection through time between the patterns on their barkcloth and the patterns found in the Blombos Cave.
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The debate in the modern scientific community about the evolution of language has more than a century of history (Jastrow, Reference Jastrow1886). However, initially, due to the absence of evidence, highly speculative or unfounded hypotheses were often proposed. This led the Société de Linguistique de Paris to prohibit the study of language evolution in 1866. As Stibbard-Hawkes recalls in his article, the continued absence of evidence was assumed to be evidence of absence of proof regarding the evolution of language. Moreover, the author convincingly argues that modern humans do not always leave evidence of what could be considered modern culture or even advanced technology. Analysis of data from the three cultures (Mbuti, G//ana, and Hadza) seems to suggest this.
Nevertheless, these three Homo sapiens cultures cannot entirely conceal characteristics of their modern cognitive capacity, which are evident in the cultural materials they produce. For example, the Mbuti pattern reproduced in Figure 1 of the present target paper comes from Tanno (Reference Tanno1981), who described the Mbuti cultural materials made by means of plant strings and occasionally duiker skin. Among the many objects and plants described, Tanno detailed the nets for net-hunting, made of Manniophton fulvum strings through a complex process. This process involves making the bast into fibers, then twisting them into two threads, which the Mbuti twist again into a string on their thighs. (Tanno, Reference Tanno1981, pp. 19, 30). The Mbuti make their quivers from duiker skin, wooden bells for the dogs, baskets from Eremospatha haullevilleana strings, and mats from Afaendidia conferta leaves “by doubling them along the midrib and pricking them into each other in succession” (Tanno, Reference Tanno1981, p. 30; see also Fig. 14 on p. 31). Tanno also describes Mbuti clothes, like the “pongo” or barkcloth, also mentioned in Stibbard-Hawkes's target article. These objects feature very special drawing patterns characterized by recursive strings of geometrical, rhomboid figures; however, the original figure includes another drawing that shows a pattern of embedded geometrical objects. Extremely interesting is the “luma,” a set of 12–15 pipes (made from the plant Olyra latifolia) of different lengths that produce various pitches, each played by one man in a coordinated manner, performing melodies and harmonies together.
The ability to manipulate geometric elements and/or create musical structures (which usually contain subordinate structures and elements, such as section, period, phrase, semi-phrase, and motif) requires a cognitive capacity that includes a specific working memory, that of modern H. sapiens (Manrique, Read, & Walker, Reference Manrique, Read and Walker2024). The same can be said of syntactic structures, which can easily embed additional elements and even complex structures.
The syntactic capacity has been addressed from various areas of scientific research, but often encounters the difficulty of providing evidence of a cognitive capacity for which we have no evidence outside of the human mind. If the evidence is scarce but enough, it has sometimes been simply concluded that the presence of modern language is “inevitable” (Dediu & Levinson, Reference Dediu and Levinson2018), or conversely, the stricter viewpoint is criticized for the lack of (more empirical) evidence because it seems that there is never enough evidence.
One must not be dogmatic, as nowadays we have new data from many different sources. Since the publication of the first data on Neanderthal DNA, many theories and viewpoints have had to be reworked. Accepting theories based on pigment residues or marks on the wall (Rodríguez-Vidal et al., Reference Rodríguez-Vidal, d'Errico, Giles Pacheco, Blasco, Rosell, Jennings and Finlayson2014), which can hardly be justified as evidence of the recursion that is evident in nets, baskets, or the diamond pattern from the Blombos Cave, or extremely small remnants of fibers from a possible fabric (Hardy et al., Reference Hardy, Moncel, Kerfant, Lebon, Bellot-Gurlet and Mélard2020), may lead us to ignore data about endocranial ontogeny (Gunz et al., Reference Gunz, Neubauer, Golovanova, Doronichev, Maureille and Hublin2012), or even to dismiss it as irrelevant.
It appears that Neanderthal-Sapiens hybrids (or Denisovan-Sapiens hybrids) were not seen as problematic or detrimental to the archaic H. sapiens species. The evidence of introgressive hybridization is widely accepted and cannot be ignored, as it has very important implications for the concept of species (Scerri et al., Reference Scerri, Thomas, Manica, Gunz, Stock, Stringer and Chikhi2018). However, this is also important regarding cognition and it does not seem to have been emphasized enough in the discussion on language evolution.
The Mbuti people reproduce, using limited means such as painting or fabric, a recursive pattern with rhomboid figures that essentially has no established limit. Precisely, we have clear evidence of this same recursive pattern, such as in remains from 75,000 years ago in the Blombos Cave (South Africa), found in more than one object, ruling out that this pattern emerged by chance (Henshilwood, d'Errico, & Watts, Reference Henshilwood, d'Errico and Watts2009).
If the ability to produce patterns like this is somehow related to the mental capacities of the brain, then it could be that they were already within the reach of H. sapiens, whose brain capacity appears to extend back to 160,000 years ago (Zollikofer et al., Reference Zollikofer, Bienvenu, Beyene, Suwa, Asfaw, White and Ponce de León2022).
All the plant-based products mentioned above are indeed perishable, unless exceptional conditions prevent it. However, there are elements that show a modern cognitive capacity behind them, with the power necessary to produce recursive patterns in drawings, musical pieces, and a multitude of structures made from braided fibers through complex manufacturing processes and the creation of knots and braids.
While it remains controversial and debatable whether other hominins could create the same types of objects as those mentioned above (nets, quivers, baskets, etc.), all present-day humans from all regions of the planet can produce this kind of patterns, and they can also learn any human language. Therefore, we should reflect the true relevance of the impact of genetic inheritance inherited from different species of the Homo genus on a common cognitive capacity in all current populations, which has existed for at least 75,000 years according to archaeological evidence.
The Mbuti people have established a connection through time between the patterns on their barkcloth and the patterns found in the Blombos Cave.
Financial support
This research was supported by the grant PID2021-128404NA-I00 funded by MCIN/AEI/ 10.13039/501100011033 by “ERDF A way of making Europe.”
Competing interest
None.