Post by Quentin Grady
One of the topics frequently discussed here is diet. Sometimes people
use what they assume is the historical diet of humans to bolster their
beliefs. Their logic often runs something like this. Humans have
strayed from the diet they were meant to eat and this has led to the
many "diseases of civilization" of which T2 diabetes might be one.
I was watching a program on the Discovery Channel on very large volcanic
eruptions about a week ago. There was this extremely large eruption
about 74 thousand years ago and some scientist have said that it
resulted a reduction in the gene pool as a consequence of the loss of
life. There may have been a reduction about 70-80 thousand years ago
that is supported by DNA evidence. Scientist have their hypotheses.
Post by Quentin Grady
Now here is something that shows how imperfect is our knowledge of
what various early humanoids really ate. One hypothesis seriously
advanced is the evolution of the larger brain in homo sapiens arose at
the same time as a dietary change one that included a more plentiful
supply of longer chain omega-3 fatty acids. Longer chain omega-3
fatty acids such as DHA feature prominently in the present day human
brain and their is much thought being given to supplementing infant
formulae to increase their DHA content. A common source of DHA is
fish but a resource less commonly availed of these days is the bone
marrow of grazing animals. Several scenarios envisage ways humans
could suddenly have increased their DHA intake. One is that during a
time of extreme deprivation that almost wiped out all homo sapiens
shell fish found in lakes in the Rift valley became a food source.
Another is that humans spreading out on the plains of Africa acted as
scavengers using primitive tools to crack open bones discarded by
predators. Another is that some made their way to the seashore near
present day Angola and gradually migrated along the coast while
another group gradually migrated down the Nile and out of Africa.
The brain size aspect of Flores man (women) is interesting. The frontal
lobes are the significant point. Considering that women usually have
smaller brains than men yet are of about equal intelligence leaves one
to wonder. Women's brains are also more symmetrical than men's and the
portion of the brain connecting the hemispheres is larger (even of other
species including prenatally).
Post by Quentin Grady
Whatever. We know T2 diabetes and coronary heart disease is in part
an inflammatory disease. At least one serious researcher attributes
the epidemic of such diseases to the existence of a genotype that
requires anti-inflammatory components in their diet. That means
berries, greens or a source of omega-3 such as EPA depending on
While the connection to Flores Man isn't that obvious here it is.
They had small brains, yet they lived on an island. On most islands
one can catch fish or collect shellfish and obtain the longer chain
omega-3 fatty acids essential for the extensive neural development.
So there is a puzzle. They weren't vegetarians if the burnt remains of
bones are indicative. It could be argued that since they were about a
metre tall they would have been expected to have a much smaller brain
than one third of humans. It is a matter of scaling from a single
dimension to three dimensions. The point is there is a new aspect to
the impact of nutrition on human evolution that has yet to be
There is another aspect of humans involving migration and susceptibility
to degenerative diseases. The mitochondria which is transmitted by the
female is significant in energy conversion use and has been connected to
cardiovascular disease risk. Somethings like lactose tolerance or
vitamin D receptors are aspects of genetic polymorphism.
A few years back I participated in a study to link surnames with the Y
chromosome. I have gotten the preliminary results from this study based
on the DNA from the sample I gave them.
The following is the link to the professor who is conducting this
Surnames, Genes and the History of Britain -
Figure 2 in this article present a world map of the Y chromosome
distributions - THE HUMAN Y CHROMOSOME: AN EVOLUTIONARY MARKER COMES OF
AGE - http://www.le.ac.uk/genetics/maj4/JoblingTS.03.NRG.Review.pdf
At the microsatellite level I only matched 3 other men in the database.
One of the issues involved may be the number of men that have had their
Y chromosome information checked. My Y chromosome is not very distinct
when it comes to the haplogroup (R1b) since it is the predominant
haplogroup in most of Western Europe; i.e., with the English, French,
Spanish, Northern Italians, Germans, and the Dutch; described as the
those in the post-glacial reexpansion of Palaeolithic inhabitants of the
What can we say? While on the surface something like Flores man seems
OT, it may not really be so far off when it comes to genetics and disease.