Brachycephaly

[64logh]

brachycephaly and globularity seems associated but they are not identical - globularity, at first sight could favorize interconnectivity in brain but it is a picture, i don't know if it is reality - I suppose the frontal region development is of greater importance - that said, brachycephalic is only a two dimensions concept, and does not cover integraly globularity - Europeans became more and more brachycephalic since Antiquity and since hte 1900's the process reversed, so? Maybe we are becoming less intelligent? in fact opposite tendancies could be in play: social life and selection linked to it, but also mechanical constraints linked to overall stature - as often multifactors result

The intelligence-brachycephaly correlation you are implying is interesting.

 

[ToBeOrNotToBe]

Brachycephaly as a whole definitely does have a correlation with intelligence, it results in a larger proportion of the brain being part of the prefrontal cortex (but also a larger brain full-stop in most cases, as shortening and widening something that's long will always tend to increase its volume). I believe brain size has a definite correlation with IQ, which means brachycephaly does too.

That being said, it probably isn't all about brain size, as if that's the case Cro-Magnons would be geniuses (when they for the most part got swarmed by farmers and wiped out by pastoralists)

 

[Saetrus]

One factor that contributed to brachycephalization is that the 150cc of brain matter lost since the neolithic revolution affected length more than breadth.

 

[ToBeOrNotToBe]

One factor that contributed to brachycephalization is that the 150cc of brain matter lost since the neolithic revolution affected length more than breadth.

Firstly, this graph is terrible as it tries to portray humanity as homogenous, whereas you'd be stupid to think the brain size of Cro-Magnon has anything to do with modern-day Khoisan. But secondly, brachycephaly is not a Neolithic trait at all - Neolithic farmers were typically Mediterranean in phenotype (meaning long-headed and thin-faced). The loss in cranial volume since the Neolithic, then, would be primarily due to a reduction in facial width, which is what the archaeological record shows.

Short-headedness only popped up recently, it's a relatively modern phenotype on the whole. Mixtures of Borreby types and Mediterranean types have been theorised to create Alpine types through a process of reduction, and this Alpine type has in turn been theorised to be the main agent of brachycephaly in Western Eurasia (creating phenotypes such as the extremely modern Dinarid, which combines a general East Mediterranean facial form with an Alpine short-headedness and wide forehead - to emphasise how modern this phenotype is, it actually postdates the beginning of copper smelting, which in the grand scheme of things is basically within recent memory).

I would have thought, though, that the last 10,000 years would have been a period of great eugenics, which would perhaps mean these decreases in cranial volume have been accompanied by more efficient "wiring", so to speak.

 

[MOESAN]

@ToBeOrNotToBe
Interesting but very complicated question of intelligence and cerebral volume.
But at first we have to look at the data:
the brachycephally among the 'alpine' pops and 'dinaric' pops (to take modern pops) is not the same: in the alpine types, there is small loss of length and a good chunk of gain in breadth; among dinaric types (not the 'borreby'like ones), we have the opposite: important loss in length, small gain in breadth, so that 'dinaric' type has a seemingly smaller braincase spite its high stature; and in fact the frontal zone is not broad at all, comparatively!
I agree with your last paragraph: there is size, and there is organisation.
&: today, skulls seem decreasing among "evolved occidental" countries spite the increase in stature, but perhaps they are a bit higher? This last aspect (height) seems factual in USA (I lack any serious recent study, a study I red compared recent USA generations to the 19/begin.20 century ones, not the very recent evolution, say since the last world war)

 

[Neander]

I2a2 is not dacian, it is sarmatian, you can find it in Slavic population and in Kurdistan. These criminals with I2a2 ydna came in Illyria in 7 century and made genocide against illyrian population, we must be happy they didn't eredicate us all. We were lucky cause Slavs were divided in nations, religions etc. If they were together there would be no Albanian today.

Brachycephaly was created after mixing of neanderthals and sapiens, while browridge was removed, the rest of the head remains intact, so the length of head is shorter, there is brachycephaly.