
Ancestral background can be determined by fingerprints - billconan
http://phys.org/news/2015-09-ancestral-background-fingerprints.html
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JoeAltmaier
Seems extremely dodgy. "African American" is pretty meaningless as an
'ancestry' label. Africa, even today, has more diversity than the rest of the
world put together. What's the odds that fingerprints would be uniform across
the whole continent?

~~~
lexcorvus
This is Lewontin's Fallacy. Briefly, there is no contradiction between the
existence of clusters and the notion that there is more variation within
clusters than between clusters. For example, the variation in height _within_
the categories "male" and "female" is greater than the variation _between_
them (i.e., the difference in mean heights), but this does not negate the
validity of the clusters "male" and "female". Indeed, only a small number of
traits are needed to determine biological sex to high accuracy—e.g., height,
skeletal density, cranial volume, waist-to-hip ratio, etc.—even though in
every individual case the variation within traits exceeds the variation
between traits [1].

Likewise, simply because the variation within sub-Saharan Africans is greater
than the variation between them and other groups doesn't mean the cluster
doesn't exist [2]. Indeed, it's easy to tell from a genetic analysis what
percentage of a person's ancestry comes from each cluster, including sub-
Saharan Africa [3].

The study in the OP indicates that fingerprints are like DNA in this regard.
That doesn't mean the study is right, simply that it shouldn't be rejected
based on Lewontin's Fallacy.

[1]: This is why anthropologists can reliably determine sex based even on
fragmentary skeletons (such as "Lucy").

[2]: The edges of the clusters are often fuzzy, but again this doesn't negate
their existence. The clusters "red" and "green" are fuzzy, too, but that
doesn't make the categories meaningless.

[3]: For example, this is the premise behind Henry Louis Gates Jr.'s PBS show
"Finding Your Roots" ([http://www.pbs.org/wnet/finding-your-
roots/](http://www.pbs.org/wnet/finding-your-roots/)). It is true that the
label "African-American" is imprecise, as most African Americans have some
European admixture, but typically over 70% of their ancestry is sub-Saharan
African ([http://isteve.blogspot.com/2013/02/henry-louis-gates-
exactly...](http://isteve.blogspot.com/2013/02/henry-louis-gates-exactly-how-
black-is.html)).

~~~
JoeAltmaier
Still confused. "African" means less than "European", given that of all the
myriad genes in Africa, only a small fraction left 40,000 years ago to
populate the rest of the planet.

There's no such thing as a single "African" cluster. There are even people
with genetics unique to the planet - in Cameroon I think. Without
distinguishing which of 100 African clusters each subject belongs to, the
study hasn't begun to say anything meaningful?

~~~
lexcorvus
_There 's no such thing as a single "African" cluster_

There's a large cluster (with, of course, lots of subclusters) that includes
almost all sub-Saharan Africans—basically, everyone except Khoisan (Bushmen)
and Pygmies. As Luigi Luca Cavalli-Sforza puts it: "differences between most
sub-Saharan Africans other than Khoisan and Pygmies seem rather small." Even
then, the African supercluster is still distinct from Europeans, and indeed
from everyone else. Cavalli-Sforza again:

 _The most important difference in the human gene pool is clearly that between
Africans and non-Africans_

For more on this important subject, I recommend these two short articles:

[http://www.vdare.com/articles/052400-cavalli-sforzas-ink-
clo...](http://www.vdare.com/articles/052400-cavalli-sforzas-ink-cloud)

[http://www.vdare.com/articles/053100-cavalli-sforza-ii-
and-s...](http://www.vdare.com/articles/053100-cavalli-sforza-ii-and-seven-
dumb-ideas-about-race)

