My first entry for Scientific American
What if I told you there were populations of chimpanzees that made spears to hunt, lived in caves, and loved playing in water? These are behaviors usually associated with ancient humans, not chimpanzees. However, recent research has revealed that there are populations of western chimpanzees (Pan troglodytes verus) that engage in all of these behaviours, and it is challenging our current understanding of chimpanzee taxonomy. In other words, they may not be chimpanzees!
congrats. Very nice article. The question in my mind is when do we get to be a species in Pan?
To be honest, although I would support reclassifying western chimpanzees (Pan troglodytes verus) to a distinct species (Pan verus) in the same way bonobos were reclassified (they used to be known as pygmy chimpanzees, I wouldn't support humans and chimps to share the same genus (Pan). Homo is a distinct genus with a great number of species that share similar morphological and behavioural characteristics that Pan do not possess. Members of the genus Homo exhibit bipedality and more distinct brain to body size ratio. There is also a massive genetic gulf between the two genera (6-8 million years).
I was teasing but do like a clean cladogram. Very nice article.
Doubled that badge. That was extremely well-written and interesting. Congratulations, theadvancedapes. I'm curious about the 'spear-use'. What is the extent of it, and how do they use them? Also, do they do any preparation for their spears, or are they just grabbing any long stick they can find and poking with it? Either way, it's impressive.
The spear construction and function is very similar to the 'fishing-rod' modifications that most chimpanzee populations make throughout Africa to procure termites and/or ants. They take a long, straight, skinny branch and use their teeth and opposable thumbs to sharpen the edge to a point. They then search for bush babies and other small nocturnal primates that sleep in holes in trees during the day. When they come upon a sleeping hole they jab repeatedly into the hole and pull out the primate on the end of the stick. Western chimpanzees are the first species, other than humans, that are known to hunt with weapons.
Crows also use spear-like sticks to stab at grubs that they can't reach. Whether you call that a weapon is subjective, but it at least displays planning and intentionality of complex, multilayer tasks. I've always found the convergence between higher birds and higher mammals to be interesting, given that our brain anatomies are so different.
Great point. Primatologists are quick to forget about how powerful convergent evolution can be in other orders of animal. I do try to contextualize discoveries of great ape behaviour and intelligence, but here I will concede that it looks possible that hunting with weapons may be more wide spread than currently understood.
No I hadn't read that before. It makes me think that we have a simplified understanding of neocortex evolution. Most scientific narratives posit that the neocortex is a unique development to mammals.
Perhaps, but the most interesting aspect is that clearly these structures were around before complex tasks and tool making were around, if we assume that reptiles, who don't display these behaviors, haven't taken a step backwards, which is possible, of course. However, the same structures are employed by birds and mammals to complete higher order processing. That's fucking convergence. And its mind-blowing, really. Pre-WWI, the German General Staff Academy used to preach that it was up to the individual officer to come up with creative solutions to battlefield problems, arguing that the German officer was so well trained that they would all come up with the same solution anyway, the optimal one. Evolution seems to work better than the German army, and that says a lot, because they were pretty damn good.
I think it would be impossible to prove but it is possible that reptiles pre-Tertiary had developed some higher-level brain functioning, although if I was a betting man, I'd say it isn't likely. There are definitely some interesting parallels between biological and cultural evolution. I was reading this today: "Evolution can in general be seen as a learning process, during which the evolving system accumulates knowledge or information about how best to survive and thrive in its environment. This has been argued by evolutionary epistemology that all evolutionary adaptation as a form of knowledge. Its main idea is that evolution is a problem-solving process based on trial-and-error, where the successful trails are selectively retained or “memorized” – thus adding to the evolving system’s store of knowledge, whereas the errors are eliminated. There is a strong selective pressure on all evolutionary systems in society: whenever there is a competition between individuals, groups, institutions, technologies or – most generally – systems of action, then, the more productive one will win." In terms of brain systems, it seems as though when the neocortex is organized in certain ways, it can produce higher level brain functioning. Now I am just interested as to why certain patterns seem to be more productive than others and why.
Evolution as knowledge and productive systems being the most successful ones are highly idealized and miss one key point: Luck. Luck has as much to do with success in evolution, and success in business, as being productive does. I might have the best gills of any creature ever born, but if my pond dries up...well, I wish I had lungs.
Pretty scary stuff once you saw "Planet of the apes". But very interesting read.
I got a bit lost with your distinction between West and Central, never really knowing what was the point. Ok, the 2 are different, but what's outstanding is that one actually hunt with fucking spears!
My point with the distinction between West and Central was to show that the current subspecies categories that have been constructed may be superficial and inaccurate. It appears as though the central and eastern subspecies are very similar genetically and behaviourally - but the western chimpanzee is genetically distinct and exhibits a different suite of behaviours. I remember when I first heard about the Fongoli chimps - it really is incredible insight into our own evolution. I don't think it is a coincidence that a population of chimps adapted to a savannah (like our ancestors were) start to develop similar technologies to our ancient hominid ancestors.