Afarensis is a 3.5-2.8 million year old hominin from the Kada Hadar member of the Hadar formation in the Middle Awash, Ethiopia. He is approximately 41 inches tall, weighs approximately 60 pounds and has a cranial capacity of a whopping 410 cc (approximately). Afarensis is currently considered to be transitional between apes and humans and displays some traits of both. Since he spends a lot of time on the couch watching monster movies, some observers question whether he is an obligate biped (although no one has observed him climbing a tree). He also has a blog called 
I'm still working part two of the ulna post. In the meantime, consider this. Researchers studying Rhesus macaques have determined that, when vocalizing, they use regions of the brain that correspond to two of the principal language centers in the human brain:
Although the coo of a monkey is acoustically very different from a high-pitched scream, the researchers found that both of these meaningful species-specific sounds elicited significantly more activity than the non-biological control stimuli in the same three regions of the macaque's brain. Moreover, these regions correspond to the key language centers in humans, with the ventral premotor cortex (PMv) corresponding to Broca's area, and the temporoparietal area (Tpt) and posterior parietal cortex (PPC) corresponding to Wernicke's area. In contrast, the non-biological sounds - which were acoustically similar to the coos and screams but had no meaning for the animals - elicited significantly less activity in these regions; rather, they were associated with greater activation of the brain's primary auditory areas. (The reason for this, the researchers suggest, is that these sounds were new to the monkeys and the primary auditory areas may be especially attuned to novel stimuli.)Based on these findings, the researchers suggest that the communication centers in the brain of the last common ancestor to macaques and humans - particularly those centers used for interpreting species-specific vocalizations - may have been recruited during the evolution of language in humans. In the macaque, these areas may currently play a parallel, prelinguistic function, in which monkeys are able to assign meaning to species-specific sounds. In addition, in light of an earlier study published by the same group, in which species-specific vocalizations of macaques activated brain regions that process higher-order visual and emotional information, the researchers suggest that the language areas of the brain may have evolved from a much larger system used to extract meaning from socially relevant situations - a system in which humans and non-human primates may share similar neural pathways.
Comments
So what was the control stimuli?
I'm just quite curious, as if they were just lound computer bleeps, that's hardly a valid comparitor (well it's valid, but it's not the best). How about a screach of another monkey/ape? I suppose the monkeys have never heard another species of monkey; but what I'm getting at is if this is a specialized area of the brain for high level communication, then in a wild macaque the warning screach of X-animal (something that it would know was bad, and something a human could geuss was bad news too, just from it's nature) wouldn't light up this area.
If on the other hand, this was an area that light up in response to the understanding of an auditory cue, then it would be activated by the roar of a lion or the hiss of a snake, etc...
You get what I'm saying?
Posted by: BilZ0r | July 24, 2006 5:32 PM
So, it's another case of a pre-existing structure being co-opted for a different purpose. Dammit, do you have to keep exposing uniquely human features that are not uniquely human at all?
Posted by: Alan Kellogg | July 25, 2006 2:59 AM
Couldn't help myself...
Posted by: afarensis, FCD | July 25, 2006 3:12 AM
So, it's another case of a pre-existing structure being co-opted for a different purpose.
Um, in what conceivable way is this a different purpose?
That's like saying a dog's nose serves a different "purpose" from our own. It's the same purpose (interpretation of vocalisation for the purposes of communication), only more advanced, surely?
Posted by: Peter Ellis | July 25, 2006 4:20 AM
It's the same purpose (interpretation of vocalisation for the purposes of communication), only more advanced, surely?
Uh... But in one case it is a monkey doing it, and in the other case it is a human doing it. (Remember, 'It is different if you are a human', or 'IIDIYAAH'.) Since, by virtue of prior assumption, clearly humans are unique and special then anything which appears to suggest that uniquely human features are unique only in scale or elaboration merely serves to confirm how unique and special we humans are. All evidence always points to our prior assumptions!
Posted by: Christopher Gwyn | July 25, 2006 11:01 AM
My apologies, some of your comments got caught by our spam filter and didn't show up till awhile ago.
So what was the control stimuli?
As I understand it, they were recorded calls from the same species (the research is reported in Nature Neuroscience).
Posted by: afarensis, FCD | July 26, 2006 12:01 AM