As long as it is a diversity of hot, not guilty chicks>
Posted on 02/07/2008 5:39:12 PM PST by blam
Third Cousins Have Greatest Number Of Offspring, Data From Iceland Shows
ScienceDaily (Feb. 8, 2008) — DeCODE scientists have established a substantial and consistent positive correlation between the kinship of couples and the number of children and grandchildren they have. The study, which analyzes more than 200 years of deCODE's comprehensive define genealogical data on the population of Iceland, shows that couples related at the level of third cousins have the greatest number of offspring.
For example, for women born between 1800 and 1824, those with a mate related at the level of a third cousin had an average of 4.04 children and 9.17 grandchildren, while those related to their mates as eighth cousins or more distantly had 3.34 children and 7.31 grandchildren. For women born in the period 1925-1949 with mates related at the degree of third cousins, the average number of children and grandchildren were 3.27 and 6.64, compared to 2.45 and 4.86 for those with mates who were eighth cousins or more distantly related.
The findings hold for every 25-year interval studied, beginning with those born in the year 1800 up to the present day. Because of the strength and consistency of the association, even between couples with very subtle differences in kinship, the authors conclude that the effect very likely has a biological basis, one which has yet to be elucidated.
This study provides the most comprehensive answer yet to the longstanding question of how kinship affects fertility in humans. Previous studies in other parts of the world have suggested that the two phenomena are positively correlated, though confounding variables, such as the impact of socioeconomic status on the size of families or age at marriage, have made the results difficult to interpret.
The analysis of such a long-term series of data from Iceland effectively eliminates these variables by encompassing an entire population which has historically been highly homogeneous both culturally and economically. Moreover, the results are strikingly consistent from eras in which Iceland was a predominantly poor and rural country, to the present-day era of a highly urbanized society with one of the highest standards of living in the world.
The authors note that the findings are somewhat counterintuitive from an evolutionary perspective because closely-related parents have a higher probability of having offspring homozygous for deleterious recessive mutations, although closer parental kinship can also decrease the likelihood of immunological incompatibility between mother and offspring, for example in rhesus factor blood type.
Perhaps most importantly, these new findings also suggest that the recent and dramatic demographic shift experienced in Iceland -- from a rural society to a highly urbanized one -- may serve to slow population growth, as individuals are exposed to a much broader range of distantly related potential mates. If so, this could be of relevance to slowing population growth in the many other -- and much more populous - societies around the world undergoing transition from closely-knit rural societies to more urbanized ones. Indeed, the UN estimates that in the 2007-2008 period the majority of the world's population will, for the first time in human history, live in town and cities.
The paper, 'An association between the kinship and fertility of human couples,' was published in the journal Science February 8, 2008.
Adapted from materials provided by deCODE genetics.
I thought it meant you share a great grandparent. People that share a grandparent are first cousins. Their children would be third cousins. One of the first cousins and the other's child would be second cousins. I'm not trying to be picky, just trying to verify.
Hey! Where’d ya get that picture of my third cousin?
--you are also wrong--my children and the children of my first cousins are second cousins--
*sigh*
The child of a first cousin to you is a first cousin once remove. The grandchild of a first cousin, first cousin twice removed.
They pumpkin on Halloween..
But...but, I thought diversity made you strong?
But that tends to up the crime rate and the prison population!
I have double first cousins. My mother and her sister married my father and his brother. Each couple had six children. My double first cousins all suffer from Marfan Syndrome (only two lived to 30) but neither me or any of my siblings were/are affected.
Cousin marriage was the norm in europe too, a hundred and fifty years ago. So watch wich stones you throw.
As long as it is a diversity of hot, not guilty chicks>
I didn’t read the entire article. But I don’t have to. I can explain it way to easily.
Couples that love eachother more are more likely to procreate more.
Couples that are more similar genetically are more strongly attracted to eachother, physically, and are thus more likely to procreate.
Obviously, there are limits to this though. Apparently, once you are closer than third cousins, the law of diminishing returns applies to physical attraction between men and women. In fact, in modern american culture, it likely reverses to the point that brothers and sisters are physically repulsed by eachother.
guilty of having adorable pouty lips, that is.
I'm analogizing from dominants in dogs, but I think it works the same way.
Very bad thing to have in the family though.
This one is only half-Icelandic.
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