Re: Brain size, IQ

Len Piotrowski (
Tue, 3 Sep 1996 14:34:14 GMT

In article <50565o$> (Gerold Firl) writes:


Another true monument to Firlism:


>The june 83 issue of scientific american has an article on homo erectus
>remains found in zhoukoudian cave by wu rukang and lin shenglong, which
>shows the steady increase in cranial capacity during the 230,000 years
>over which the cave was occupied. The earliest skull was about 500,000
>years old, with a capacity of 915 cc, while the latest was 1140 cc from
>about 230,000 bp.

Homo erectus hasn't been included with modern humans, as far as I am aware,
regardless of any trends in brain size from Chinese sites. Despite being
tangential to the current discussion, I would also question the applicability
of physical data from one region's sites to an entire species and subsequent
evolutionary events!

>I don't have comparable data for h. sapiens, but I would expect similar
>trends. (Modern cranial capacity is around 1500 cc)

The reason you have no comparable data for H. sapiens is because there is
none to compare with. There simply there is no justification to extrapolate
the cranial results from Chinese H. erectus sites to other areas of the world
or other time periods or other species.

>There is no distinct boundary between h. erectus and h. sap, whatever
>your semiological evidence to the contrary.

The application of Firl's information management style at it's best! The facts
may be interesting, but so what!

>Archaic h. sapiens looks
>just like late h. erectus, and vice versa.


>I would expect cranial
>capacity of h. sap to have increased from approcimately 1200 cc 150,000
>years ago to the present 1500.

We all await the ripening of your expectations, Firl!

>|> Well, if head size is correlated with brain size (which you may not be ready
>|> to concede) then the only significant differences in head size resolved by the
>|> fossil record are at speciation events. In between those episodes there
>|> appears to be no significant "heritability" of head size in the record.
>|> Perhaps you can clarify this anomalous situation?

>No anomaly - you are simply misinformed. Cranial capacity does not
>suddenly "jump" at "speciation events" - what's more, there are no
>speciation events.

Double boggle!

>Biological evolution moves much more gradually than
>that. On a geological time scale, species can appear very suddenly,

No felt contradiction in this statement, Firl?

>as eldridge has demonstrated, there _are_ intermediate forms. Given the
>paucity of the fossil record, there may appear to be discrete events,
>but at finer levels of discrimination evolution proceeds one mutation
>at a time.

Perfect implementation of the negative evidence, Firl. The evidence is there,
you just can't see it!

See 'ya,


"If you can't remember what mnemonic means, you've got a problem."
- perlstyle