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1. Male circumcision is a weapon in the
sperm wars
http://www.newscientist.com/channel/sex/dn14069-male-circumcision-is-a-weapon-in-the-sperm-wars.html?feedId=online-news_rss20
Circumcision and other forms of male genital mutilation have always been a
puzzle. The ritual mutilations can leave the man vulnerable to infection and
even death. So why do some societies insist on such a risky ritual for their
men?
There may be an evolutionary explanation, according to Christopher Wilson, of
Cornell University in New York, US. It could function to reduce a young man's
potential to father a child with an older man's wife, he says.
Sperm competition theory predicts that males will evolve ways to ensure that
their sperm, and not another male's, fertilises a female's eggs. Genital
mutilation, in this view, is just another way to win the sperm war.
In some forms of mutilation, the handicap to sperm competition is obvious. There
is subincision, for example, where cuts are made to the base of the penis. This
causes sperm to be ejaculated from the base rather than the end, and is
performed in several Aboriginal Australian societies, says Wilson.
In some African and Micronesian cultures, young men have one of their testicles
crushed.
Male genital mutilation makes it less likely that a male will manage to father a
child with another man's wife, Wilson says.
Home advantage
Circumcision is one of the less painful forms of mutilation, but it is also less
effective at reducing sperm competition. Wilson suggests, however, that the lack
of a foreskin could make insertion or ejaculation slower, meaning brief, illicit
sex is less likely to come to fruition and lead to a pregnancy.
Younger men, he says, willingly submit to having their reproductive ability
reduced because they benefit socially from the older men, by forming alliances,
and by gaining access to weapons or tribal lore.
The older men have also gone through the ritual, and seen their own reproductive
effectiveness reduced. But if a man with, say, four wives wants to ensure that
any children his wives produce are his, there is pressure to make sure other men
can't successfully impregnate them.
The husband's own reproductive ability is impaired, but continuous and repeated
access to his wives makes up for it, while any genital mutilation is a greater
handicap to an interloper trying to sneak brief occasional sex with his wives.
Price of alliance
"An older married man must form alliances, or associate with younger or
unmarried men at some point, and it would be better to associate with and invest
preferentially in those who are least likely to threaten his paternity,
especially in societies where cuckoldry is rife," says Wilson.
"Men who demand genital mutilations as part of the price for alliance and
investment would be less vulnerable to exploitation of such relationships and
loss of paternity to peers."
Wilson has now tested the idea. If the sperm competition theory is correct, he
reasoned, then male genital mutilation should be more common in societies where
men tend to have multiple wives, especially those in which the wives live apart
from the husband.
The mutilation would also probably be carried out in a public setting, witnessed
mostly by other men, and performed by a non-relative. Men who refused would face
social sanctions.
Who's the daddy?
Wilson searched anthropological databases and found that his predictions were
borne out: 48% of highly polygynous societies practice some form of male genital
mutilation, and in societies in which wives live in separate households that
increases to 63%.
Only 14% of the monogamous societies in the database practice male genital
mutilation.
It might also be the case that selection works at a group level, so that
societies that enforce mutilation are more stable because of less conflict over
paternity, Wilson says.
David Barash, an evolutionary biologist at the University of Washington in
Seattle, US, says that the paper makes a convincing case.
"Wilson has tackled a perplexing question and come up with a persuasive
preliminary answer to an evolutionary enigma: why do men submit to procedures
that seem to reduce their fitness?" he says.
Journal reference: Evolution and Human Behavior (vol 29 p 149)
2. Most recent common ancestor (MRCA)
http://en.wikipedia.org/wiki/Most_recent_common_ancestor
Extracts of Interest:
Rohde, Olson, and Chang (2004)[3], using a non-genetic model, estimated that the
MRCA of all living humans may have lived within historical times (3rd millennium
BC to 1st millennium AD). Rohde (2005)[5] refined the simulation with parameters
from estimated historical human migrations and of population densities. For
conservative parameters, he pushes back the date for the MRCA to the 6th
millennium BC (p. 20), but still concludes with a "surprisingly recent" estimate
of a MRCA living in the second or first millennium BC (p. 27). An explanation of
this result is that, while humanity's MRCA was indeed a Paleolithic individual
up to early modern times, the European explorers of the 16th and 17th centuries
would have fathered enough offspring so that some "mainland" ancestry by today
pervades even remote habitats. The possibility remains, however, that a single
isolated population with no recent "mainland" admixture persists somewhere,
which would immediately push back the date of humanity's MRCA by many millennia.
While simulations help estimate probabilities, the question can be resolved
authoritatively only by genetically testing every living human individual.
Other models reported in Rohde, Olson, and Chang (2004)[3] suggest that the MRCA
of Western Europeans lived as recently as AD 1000. The same article provides
surprisingly recent estimates for the identical ancestors point, the most recent
time when each person then living was either an ancestor of all the persons
alive today or an ancestor of none of them. The estimates for this are similarly
uncertain, but date to considerably earlier than the MRCA, according to Rohde
(2005) roughly to between 15,000 and 5,000 years ago.[5] [2].
3.
MRCA
of mtDNA
Only 6000 Years!
A Simple Experiment Which Should Refute Creationism?
http://s8int.com/article1-simple.html
by Andy Nobles
4. Female Arab or East African Presence
in Ancient Scandinavia?
Rare mtDNA haplogroups and genetic differences in rich and poor Danish
Iron-Age villages
by: L Melchior, MTP Gilbert, T Kivisild, N Lynnerup, J Dissing
http://www.citeulike.org/user/ryanraaum/article/2014557
The Roman Iron-Age (0-400 AD) in Southern Scandinavia was a formative
period, where the society changed from archaic chiefdoms to a true state
formation, and the population composition has likely changed in this period due
to immigrants from Middle Scandinavia. We have analyzed mtDNA from 22
individuals from two different types of settlements, B?ebjergg?d and Skovgaarde,
in Southern Denmark. B?ebjergg?d (ca. 0 AD) represents the lowest level of free,
but poor farmers, whereas Skovgaarde 8 km to the east (ca. 200-270 AD)
represents the highest level of the society. Reproducible results were obtained
for 18 subjects harboring 17 different haplotypes all compatible (in their
character states) with the phylogenetic tree drawn from present day populations
of Europe. This indicates that the South Scandinavian Roman Iron-Age population
was as diverse as Europeans are today. Several of the haplogroups (R0a, U2, I)
observed in B?ebjergg?d are rare in present day Scandinavians. Most
significantly, R0a, harbored by a male, is a haplogroup frequent in East Africa
and Arabia but virtually absent among modern Northern Europeans. We suggest that
this subject was a soldier or a slave, or a descendant of a female slave, from
Roman Legions stationed a few hundred kilometers to the south. In contrast, the
haplotype distribution in the rich Skovgaarde shows similarity to that observed
for modern Scandinavians, and the B?ebjergg?d and Skovgaarde population samples
differ significantly (P ≈ 0.01). Skovgaarde may represent a new upper-class
formed by migrants from Middle Scandinavia bringing with them Scandinavian
haplogroups. Am J Phys Anthropol, 2007. ? 2007 Wiley-Liss, Inc.
Brit-Am
Comment:
According to our understanding (see: http://www.britam.org/Questions/mtDNA.html
)
the rare haplogroups R0a, U2, I are all found in the Middle East though also
being present at low rates
in Western Europe.
On the other hand,
The haplogroup R0a described as "frequent in East Africa and Arabia but
virtually absent among modern Northern Europeans"
is however a subgroup of R which is considered the PARENT of all major North
European haplogroups.
5. The length of life in classical
Greece
http://dienekes.blogspot.com/
Batrinos ML.
Contrary to the commonly held belief that in antiquity and as late as 1700 A.D.
normal lifespan was about 35 years, there are indications that the ancient
Greeks lived longer. In a study of all men of renown, living in the 5th and 4th
century in Greece, we identified 83 whose date of birth and death have been
recorded with certainty. Their mean +/- SD and median lengths of life were found
to be 71.3+/-13.4 and 70 years, respectively. Although this cohort cannot be
considered as representative of the general population, it is however indicative
of a long length of life in classical Greece. Good living conditions and a mild
climate at the time of intellectual and artistic excellence, the use of slaves
for hard work, an animated social life in which the aged actively participated
and, not least of all, the respect that aged people were accorded by the
younger, all favored a longer length of life and eugeria (happy aging) or
eulongevity in classical Greece.
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