# When did the brain areas evolve to put handles on hand axes **URL:** \ **Category:** Factual Questions\ **Created:** [May 24, 2012, 10:05pm UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012 "2012-05-24T22:05:27Z")\ **Posts on this page:** 19\ **Page:** 1
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [May 24, 2012, 10:05pm UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/1 "2012-05-24T22:05:27Z")
Hand axes were the tools of primates from about 1.7 million years ago to maybe 100k or so years ago. I was watching a documentary once where the narrator said that adding handles to the axes was as unthinkable as birds building machines would be since the brain areas hadn’t been evolved yet. So what brain areas evolved that allowed primates to turn hand axes into actual axes (with handles), and when did that occur? ---
**Author:** ![Darryl\_Lict](https://avatars.discourse-cdn.com/v4/letter/d/7cd45c/32.png) [@Darryl\_Lict](https://boards.straightdope.com/u/Darryl_Lict)\ **Post date:** [May 24, 2012, 10:15pm UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/2 "2012-05-24T22:15:25Z")
I’m not sure it was evolution rather than an invention. Some birds and chimpanzees both use tools. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [May 24, 2012, 10:47pm UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/3 "2012-05-24T22:47:56Z")
> [@Wesley\_Clark](#): > > Hand axes were the tools of primates from about 1.7 million years ago to maybe 100k or so years ago. I’m puzzled by this statement - they have been used by primates much more recently than 100,000 years ago (I used one yesterday). ---
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [May 24, 2012, 10:58pm UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/4 "2012-05-24T22:58:07Z")
> [@Xema](#): > > I’m puzzled by this statement - they have been used by primates much more recently than 100,000 years ago (I used one yesterday). My point is that the handle adds leverage and power to the axe, but primates didn’t figure that out for about 1.6 million years or so. For that period people just held the axe in the palm of their hand. I believe I saw an article once that detailed which brain regions evolved to let us comprehend how adding a handle would make the axe more stable and powerful but I can’t find it right now. ---
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [May 24, 2012, 11:03pm UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/5 "2012-05-24T23:03:23Z")
An axe isn’t a handaxe with a handle. It’s a stick with a sharp rock attached. Our earliest ancestors used sticks to hit things with. Even chimps sometimes do this, although infrequently. So they moved from picking up random sticks to looking around for particularly good sticks and keeping them, to fashioning good sticks by trimming them. Now you’ve got a purpose-built club. All you have to do is stick some sharp rocks to the club, and you’ve got an axe. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [May 24, 2012, 11:31pm UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/6 "2012-05-24T23:31:52Z")
> [@Lemur866](#): > > Our earliest ancestors used sticks to hit things with. Even chimps sometimes do this, although infrequently. So they moved from picking up random sticks to looking around for particularly good sticks and keeping them, to fashioning good sticks by trimming them. Now you’ve got a purpose-built club. All you have to do is stick some sharp rocks to the club, and you’ve got an axe. Yet despite this simplification, as the OP points out it took us millions of years to figure this out. More astoundingly, Tasmanian Aborigines \*lost \*this technology and had no concept of hafted tools when they first came into contact with Europeans. So clearly the concept is nowhere near as simple as it seems. The fact that at least one group of modern humans lost the ability to manufacture hafted axes suggests that the OP is based on an erroneous assumption. If there was some specific area of the brain that made it possible to comprehend hafted tools then it would then it should be impossible for modern humans not to understand the concept. Yet we know that they did, and that they lost that technology within a few thousand years. So I doubt very much if there is any specific section of the brain that deals with the concept. It would appear to be just a generic technological advance that was invented once and then passed on to subsequent generations. In that respect it’s no different to the wheel or writing or any other technology that seems “obvious” once you are taught it, but that clearly isn’t obvious at all. We don’t argue that there is a specific section of the brain that deals with writing or wheels, and I can’t see any reason to assume there is a specific section of the brain that deals with hafted tools. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [May 24, 2012, 11:40pm UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/7 "2012-05-24T23:40:29Z")
> [@Wesley\_Clark](#): > > I believe I saw an article once that detailed which brain regions evolved to let us comprehend how adding a handle would make the axe more stable and powerful but I can’t find it right now. If you did, it was bullshit (or, at best, wild speculation, going far beyond any available evidence). The answer to your question is that we don’t know. We are nowhere near understanding the brain well enough. (And much of what we do know comes from the study of monkeys and other animals, rather than humans, so they won’t answer this question. The really cool experiments involve doing things you are not normally allowed to do with humans, like sticking electrodes deep into brain tissue.) It is most unlikely, anyway, that one particular brain area was involved in this invention. Like most actual performances, it probably involves many parts of the brain working together. We can say things like some brain areas are (mostly) concerned with vision, or hearing, or language understanding, etc., and, to some extent, which are concerned with things like spatial cognition or object identification, but that is very different from saying which parts are involved in inventing axe handles. ---
**Author:** ![heathen\_earthling](https://avatars.discourse-cdn.com/v4/letter/h/13edae/32.png) [@heathen\_earthling](https://boards.straightdope.com/u/heathen_earthling)\ **Post date:** [May 25, 2012, 12:11am UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/8 "2012-05-25T00:11:13Z")
> [@Wesley\_Clark](#): > > My point is that the handle adds leverage and power to the axe, but primates didn’t figure that out for about 1.6 million years or so. For that period people just held the axe in the palm of their hand. I expect the invention of handles also reduced the number of hand injuries related to using axes, which seems like an even simpler idea for people to grasp than physics concepts like leverage and power. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [May 25, 2012, 12:36am UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/9 "2012-05-25T00:36:18Z")
> [@Blake](#): > > Yet despite this simplification, as the OP points out it took us millions of years to figure this out. More astoundingly, Tasmanian Aborigines \*lost \*this technology and had no concept of hafted tools when they first came into contact with Europeans. So clearly the concept is nowhere near as simple as it seems. Is it really the consensus view that Tasmanian Aboriginals were unable to make hafted tools? And if so, did they lose the ability or the need? At any rate, Neanderthals had hafted tools, although I don’t think they had any hafted axes. Maybe just spears and knives. That would lead me to believe that knowledge of hafting was possessed by our common ancestor, at least 500k years ago. ---
**Author:** ![whatever\_name](https://avatars.discourse-cdn.com/v4/letter/w/bc8723/32.png) [@whatever\_name](https://boards.straightdope.com/u/whatever_name)\ **Post date:** [May 25, 2012, 12:46am UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/10 "2012-05-25T00:46:30Z")
all I can say is that we’re extremely lucky to have hands like what we’ve got, it helped fuel our brain evolution for bigger and better things. more accomplishments were set in stone at some point. its hard to say at what in point everything was determined, maybe before the big bang (if there was one). but that’s beside the point. ---
**Author:** ![Trinopus](https://avatars.discourse-cdn.com/v4/letter/t/2bfe46/32.png) [@Trinopus](https://boards.straightdope.com/u/Trinopus)\ **Post date:** [May 25, 2012, 1:08am UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/11 "2012-05-25T01:08:01Z")
I’ve seen, in nature, sticks with rocks embedded in them – a tree or bush simply grew around a chunk of rock. A completely natural hafted-axe. Actually, the key technology is in the binding! Someone was clever enough to figure out how to tie things together with sinews. From that point on, things like axes with handles, and arrowheads or spearheads attached to shafts – and clever artwork such as the Zuni fetishes! – are relatively obvious and easy. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [May 25, 2012, 1:21am UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/12 "2012-05-25T01:21:39Z")
> [@John\_Mace](#): > > Is it really the consensus view that Tasmanian Aboriginals were unable to make hafted tools? And if so, did they lose the ability or the need? There’s no doubt that Tasmanians couldn’t make hafted tools. As for need, all we can say is that they were universal before the island was isolated from the mainland, and the people living a hundred miles away on the mainland in identical ecological and environmental conditions continued to find them useful. Tasmanians also lost the ability to make fishhooks, needles, clothing and freakin’ \*fire \*amongst many, many other things. So it would require some exceptional special pleading to suggest that they stopped making hafted tools because they had no need. The simple explanation is that they lost the technology and couldn’t reinvent it. > [@](#): > > At any rate, Neanderthals had hafted tools, although I don’t think they had any hafted axes. Maybe just spears and knives. Spears aren’t considered hafted tools, they are just spears. ---
**Author:** ![TonySinclair](https://avatars.discourse-cdn.com/v4/letter/t/49beb7/32.png) [@TonySinclair](https://boards.straightdope.com/u/TonySinclair)\ **Post date:** [May 25, 2012, 1:27am UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/13 "2012-05-25T01:27:24Z")
> [@Blake](#): > > Yet despite this simplification, as the OP points out it took us millions of years to figure this out. More astoundingly, Tasmanian Aborigines \*lost \*this technology and had no concept of hafted tools when they first came into contact with Europeans. So clearly the concept is nowhere near as simple as it seems. > > The fact that at least one group of modern humans lost the ability to manufacture hafted axes suggests that the OP is based on an erroneous assumption. If there was some specific area of the brain that made it possible to comprehend hafted tools then it would then it should be impossible for modern humans not to understand the concept. Yet we know that they did, and that they lost that technology within a few thousand years. Not being able to comprehend something is completely different from not being able to invent it. The human brain, presumably, hasn’t changed much in the last 400 years, and yet nobody could do calculus 400 years ago, while I took it in tenth grade. And trust me, I’m no Isaac Newton. Breakthrough discoveries are unpredictable. The first guy in Tasmania to use a handle on his axe probably didn’t sit down and figure it out; it was probably more a case of Og randomly hitting rocks with a club, and one of them was sharp on two edges, and one sharp edge made it get stuck on the end of the club, and suddenly he had an axe. And since the warriors _could_ immediately comprehend that this was a very powerful weapon, they might have tried to restrict knowledge of it to their own tribe, either enslaving or killing rivals who saw it. And then something happened, maybe a natural disaster or a plague, that wiped the whole tribe out, and the knowledge was lost, and nobody else had the same happy accident as Og to rediscover it. ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [May 25, 2012, 1:44am UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/14 "2012-05-25T01:44:30Z")
> [@TonySinclair](#): > > Not being able to comprehend something is completely different from not being able to invent it. The human brain, presumably, hasn’t changed much in the last 400 years, and yet nobody could do calculus 400 years ago, while I took it in tenth grade. And trust me, I’m no Isaac Newton. > > Breakthrough discoveries are unpredictable. The first guy in Tasmania to use a handle on his axe probably didn’t sit down and figure it out; it was probably more a case of Og randomly hitting rocks with a club, and one of them was sharp on two edges, and one sharp edge made it get stuck on the end of the club, and suddenly he had an axe. > > And since the warriors _could_ immediately comprehend that this was a very powerful weapon, they might have tried to restrict knowledge of it to their own tribe, either enslaving or killing rivals who saw it. And then something happened, maybe a natural disaster or a plague, that wiped the whole tribe out, and the knowledge was lost, and nobody else had the same happy accident as Og to rediscover it. What? First off, as i already pointed out, if there was a section of the brain that was specifically to "comprehend how adding a handle would make the axe more stable " then there could not be human groups who could no comprehend how adding a handle would make the axe more stable. Yet it is a fact that such a group existed. So clearly such an area of the brain does not exist. Invention doesn’t enter into it, unless you are suggesting that there is a section of the brain devoted to understanding the uses of calculus. Beyond that, Tasmanians had hafted weapons 10, 000 years ago. They lost them at some point in time, along with a whole slew of other technology. This wasn’t technology that wasn’t invented. It was technology that was lost. And finally, the idea that hafted tools might have derived from shards of stone that became accidentally embedded in a club is just farcical. Hafted tools are carefully constructed bits of engineering with every step in the construction process needing to be planned out on advance, they aren’t accidental. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [May 25, 2012, 2:18am UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/15 "2012-05-25T02:18:35Z")
[This Science article](http://www.sciencemag.org/content/291/5509/1748.full) addresses some of the issues of the op but may be behind the pay wall. It’s Science 2 March 2001: Vol. 291 no. 5509 pp. 1748-1753 DOI: 10.1126/science.1059487 if you want to find it otherwise. > [@](#): > > The earliest direct evidence of hominid technology dates to 2.5 Ma in the Ethiopian Rift Valley (15, 16), comprising sharp-edged slivers and lumps of stone, hammer stones and anvils, and bones with hammer marks and cut marks from butchery and marrow extraction. This simple technology is named the Oldowan Industrial Complex … Oldowan technology seems simple, reflecting the mental capacities of extant apes (24), but it actually reflects manual skills far exceeding those of chimpanzees … > > … Homo habilis is usually considered the first tool maker. Cranial endocasts show that its left hemisphere has an impression of Broca’s area (40, 41). Broca’s area is involved in oro-facial fine motor control and language and is adjacent to and probably derived from the area for precise hand motor control (42) … > > … Large cutting tools (LCTs), typically about 10 to 17 cm long (Fig. 2), were added to the Oldowan toolkit around 1.5 Ma, marking the advent of the Acheulean Industrial Complex. The Acheulean was manufactured byH. erectus and its larger-brained descendant H. heidelbergensis, and dates between 1.5 and 0.3 Ma (50, 51). … > > … Technological and cultural evolution accelerated ∼300,000 years ago (300 ka), during the Middle Paleolithic (MP) and its sub-Saharan African correlate, the Middle Stone Age (MSA). These advances were made by Neanderthals, late archaic humans, and anatomically modern humans (72, 76). Regional stylistic and technological variants are clearly identifiable, suggesting the emergence of true cultural traditions and culture areas (77). LCTs were supplanted by smaller tools from Levallois and radial cores (Fig. 3). Levallois core technology is a sophisticated strategy for efficiently producing relatively standardized artifacts, and may reflect more complex cognitive abilities (78). Stemmed (tanged) points and other tools (77), microwear traces from mounts (79), and organic residues of mastic (80) indicate hafted composite tools, probably as early as the Acheulean to the MP/MSA transition. Stone-tipped spears, knives, and scrapers mounted in shafts and handles represent an order-of-magnitude increase in technological complexity that may be analogous to the difference between primate vocalizations and human speech. … > > … Speech and composite tool manufacture involve sequences of nonrepetitive fine motor control and both are controlled by adjacent areas of the inferior left frontal lobe (42, 82). A composite tool may be analogous to a sentence, but explaining how to make one is the equivalent of a recipe or short story. If composite tool manufacture and grammatical language coevolved ∼300 ka, then Neanderthals and modern humans could speak. This is consistent with reconstructions of fossil hominid vocal tracts that suggest that their last common ancestor, H. heidelbergensis, could also speak (83). > > The acquisition and modification of each component of a composite tool involve planned sequences of actions that can be performed at different times and places, such as flaking a stone point, cutting and shaping a wooden shaft, and collecting and processing binding materials. The complex problem solving and planning demanded by composite tool manufacture may have influenced the evolution of the frontal lobe. Functional magnetic resonance imaging demonstrates that the frontopolar prefrontal cortex selectively activates only when imagining a main objective while performing related secondary tasks (84). Switching between unrelated tasks has no effect. Composite tool manufacture demands the planning and coordination of different kinds of subsidiary tasks and may have coevolved with this frontal lobe parallel processing module. … A [more recent Science article](http://www.sciencemag.org/content/336/6080/408.summary?sid=86a2115d-a632-4137-bc0f-ed5e789d5b54) expands the concept that composite tools may have co-evolved with language. > [@](#): > > Such tools gradually became more refined, achieving a high level of sophistication about 700,000 years ago with Late Acheulean handaxes. High-tech by comparison, these were deliberately crafted into oval or teardrop shapes in multistep manufacturing processes that required planning and significant skill. One hypothesis is that the cognitive capabilities that supported toolmaking gave the toolmakers language-ready brains; then the benefits of instructing succeeding generations in how to make tools drove the emergence of language. > > Evidence supporting this hypothesis began accumulating in the past decade as brain imaging found overlaps in the neural areas associated with language and those involved in tool use. More recently, groups led by Dietrich Stout, an archaeologist at Emory University in Atlanta, and Thierry Chaminade, a cognitive neuroscientist at Aix-Marseille University in Marseille, France, have taken to actually reproducing stone tools while tracking neural activity with positron emission tomography. In a series of experiments reported over the past 5 years, they showed that Oldowan toolmaking activates the left ventral premotor cortex, a region previously shown to be involved in both manual grip coordination and phonological processing. Late Acheulean tool production relies on those same regions, they found, plus other areas of the brain, including the inferior frontal gyrus, which is associated with abstraction and hierarchical organization (needed for executing subgoals along the way to a final product, for example), as well as larger scale discourse and language processing. > > Follow-up experiments in which Bruce Bradley, an archaeologist at the University of Exeter in the United Kingdom, wore a data glove to record left hand finger movements suggested that it was the cognitive demands of making Acheulean tools—not left hand manipulation—that lit up the right brain. > > The results “establish plausible evolutionary links” between specific toolmaking skills and language processing … ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [May 25, 2012, 1:14pm UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/16 "2012-05-25T13:14:33Z")
On reread I realize that reading those bits taken out of the context of the article may be a bit hard to follow. The essence is as follows: Complex composite tools, like hafted axes, began to appear about 300K years ago in several human lines. While not discussed in these articles, it is not completely clear they invented by these different groups independently or spread as an idea once invented by one group. It does seem that this advanced tool making capacity required growth in brain areas overlapping those required for human level language development and longer term planning, including one adjacent to Broca’s area and various frontal lobe areas, such as areas of the inferior left frontal lobe, the frontopolar prefrontal cortex, and the inferior frontal gyrus. The hypothesis expressed in these articles is that advanced tool making and language capacities drove each other. This hypothesis dovetails nicely with other work that supports the concept that language began primarily as gestural (hand signs) and had vocalization built on top of it. (See [this article on mirror neurons](http://www.unipr.it/arpa/mirror/pubs/pdffiles/ferrari/Curr_Directions_Psy.pdf) for a taste of those speculations.) ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [May 25, 2012, 1:30pm UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/17 "2012-05-25T13:30:42Z")
> [@Blake](#): > > There’s no doubt that Tasmanians couldn’t make hafted tools. As for need, all we can say is that they were universal before the island was isolated from the mainland, and the people living a hundred miles away on the mainland in identical ecological and environmental conditions continued to find them useful. Tasmanians also lost the ability to make fishhooks, needles, clothing and freakin’ \*fire \*amongst many, many other things. So it would require some exceptional special pleading to suggest that they stopped making hafted tools because they had no need. The simple explanation is that they lost the technology and couldn’t reinvent it. I was looking for cites. I have to wonder how rigorous the anthropological research was, at the time, while they were being wiped out by disease and warfare. Tasmania is a large place, and there were numerous tribes living all over the island, so I’m not even sure that it makes sense to speak of Tasmanians in such monolithic terms. > [@](#): > > Spears aren’t considered hafted tools, they are just spears. Spears can be either hafted (a point attached) or not (just a sharpened stick). ---
**Author:** ![RaftPeople](https://avatars.discourse-cdn.com/v4/letter/r/6f9a4e/32.png) [@RaftPeople](https://boards.straightdope.com/u/RaftPeople)\ **Post date:** [May 25, 2012, 3:40pm UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/18 "2012-05-25T15:40:42Z")
> [@Blake](#): > > First off, as i already pointed out, if there was a section of the brain that was specifically to "comprehend how adding a handle would make the axe more stable " then there could not be human groups who could no comprehend how adding a handle would make the axe more stable. Yet it is a fact that such a group existed. So clearly such an area of the brain does not exist. Clearly you misunderstand how the brain works. Read up on **DSeid’s** cites which exactly answer the question posed by the OP: “So what brain areas evolved that allowed primates to turn hand axes into actual axes (with handles), and when did that occur?” ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [May 25, 2012, 4:03pm UTC](https://boards.straightdope.com/t/when-did-the-brain-areas-evolve-to-put-handles-on-hand-axes/623012/19 "2012-05-25T16:03:55Z")
Can we stop using “primate” in this context and start using Human ancestor or something similar? “Primate” is an extremely broad term that includes monkey, lemurs and other mammals that are quite distantly related to us, although we are all in the same order. Better to use the genus _Homo_, since that’s what we’re talking about.