Genetic diversity and Population genetics An individual organism's phenotype results from both its genotype and the influence from the environment it has lived in. A substantial part of the phenotypic variation in a population is caused by genotypic variation. The frequency of one particular allele will become more or less prevalent relative to other forms of that gene. Variation disappears when a new allele reaches the point of fixation —when it either disappears from the population or replaces the ancestral allele entirely.
A relatively minor point, though not trivial, has been the issue of the biological relatedness of the Jewish people, and their relatedness to the nations among whom they were resident.
This particular point became more starkly relevant with a scientific understanding of human genealogy and genetic relationship in the 18th and especially 19th centuries, but its root can be traced back to antiquity. Jews are not simply a set of individuals who espouse a belief in the God of the Jews, or hold to the laws of the God of the Jews.
Rather, one aspect of Jewish identity is its collective component whereby the adherents of the Jewish religion also conceive of themselves as a particular nation or tribe, and therefore bound together by a chain of biological descent. Of course these issues can not be understood except in light of a complex historically contingent sequence of events.
Our understanding of what it means to be Jewish today, or the understanding of Jews themselves as to their own identity, is the outcome of a long process where self-identified Jews interacted with the broader milieu, as well as evolving in situ.
In other words, the Jewish people and the seeds of the Jewish Diaspora were shaped by developments within and without the Jewish culture, and these developments left an impact on the genes of the Jewish people.
And yet it is descents of the adherents of Rabbinical Judaism, the Judaism of the Pharisees, which we think of when we think of Jews even the non-Orthodox traditions emerged out of a cultural milieu where Orthodox Judaism was normative.
The vast majority of the Jews of the world trace their lineage back to the groups who organized their lives around not just the Bible, but also the Talmud, and subsequently commentaries and rulings by rabbis who were trained in the Talmud. Today these Jews fall into three broad groups, the Ashkenazim, Sephardim and Mizrahim.
The Ashkenazim are rather easy to define, as they are the Jews of Central Europe who have been so prominent over the past few centuries. The Sephardim were originally the Jews of Spain, but after their expulsion in they settled in the Ottoman Empire, and to a lesser extent in other regions of Europe such as the Netherlands.
A major confounding issue with the modern Sephardim is that in the Ottoman lands they encountered and interacted with preexistent Jewish communities, who often maintained a distinctive identity subsequent to the influx of the Sephardim.
Though in most cases, such as in Morocco and Syria, the Sephardim became culturally dominant and assimilated the indigenous Jewish community into their identity though they often abandoned Ladino, the language they brought from Spain, for the local lingua francain other cases two distinct Jewish communities were coexistent down down to the modern era e.
Finally, the Mizrahim are Jews of the East or Oriental Jews, those Jews whose ancestors hail from Muslim lands where the Sephardim were never a presence. To a great extent the Mizrahim identity is a recent catchall constructed to identify a real dividing line between those groups which are the products of the Sephardic-indigenous synthesis, such as the Moroccan Jews, and those which are not, such as the Yemeni Jews.
Often all non-Ashkenazi Jews are referred to as Sephardic because of a common religious liturgy which binds them. But naturally it gets more complicated than this. Between the rise of Islam and Christianity as the dominant religious civilizations in which Jews were embedded and the Enlightenment Rabbinical Judaism had established a modus vivendi.
Jews were a corporate entity, a minority subordinate to the majority, whose relationship with the majority was mediated through eminent individuals who spoke for and had power over the community. Though often fraught in the execution in the abstract the position of Jews within pre-modern political units was not controversial; Jews were subjects with obligations, often a useful minority for potentates.
They were not citizens with rights and responsibilities. Over the past few centuries that has obviously changed.
The French Revolution and the emergence of the idea of a nation-state where all citizens have equal rights and responsibilities before the law, along with a scientific concept of race, complicated the Jewish relationship with the societies in which they were resident, particularly in Europe though pan-Turk and pan-Arab nationalism were analogous and resulted in similar problems of identity.
The Nazi total extermination program stood in contrast to previous assaults on the existence of Jewish community, where conversion to Christianity, and assimilation more broadly, were plausible goals.
The Nazis aimed to eliminate not just the culture of the Jews, but their very biological existence. This explains the secular nature of the original Zionist project, whose aim was to create a national homeland for the Jews as a people, and so normalize them as a nation among nations, rather than being among the nations this was a project which religious and assimilationist Jews initially opposed.
With the Holocaust, and the post-World War II rejection of racial nationhood, the often pseudo-scientific practice of measuring and categorizing people according to skull metrics, and more legitimately blood groups, fell into disrepute. Some scholars began to reconfigure the Jews not as a biological descent group, but as a religious ideology or confession which eventually became an ethnic identity.
The most extreme proponents of the cultural model presumed that Jewish groups emerged through cultural diffusion and religious proselytization. In other words this school transformed Jewishness into what the German Reform movement had attempted, making of Jews just another religious confession with no ethnic connotations and therefore entailing a reinterpretation of some aspects of Chosen Peoplehood.
But the pendulum has swung back, in part thanks to the rise of genetic science, and in part broader currents in the Jewish world. In regards to the second I will note that the American Reform movement has pulled back from its more aggressive accommodations with the sensibilities of gentiles.
Of particular relevance for the topic at hand, Reform Judaism has reversed its rejections of the idea of Jewish nationhood.
I suspect this is in large part because American Jews, and Jews in Western nations more generally, feel less need to prove that they belong by aligning themselves self-consciously to mainstream conceptions of religious identity as anti-Semitism has declined.
And now we come to genetics. The genetics of Jews are a large set of related fields. Though the ultimate aim of much research is to clarify population stratification in association studies, over the past few years there has been a great deal of light shed on the possible origins of and the relationships of Jews to each other and other populations.
Originally the focus was on uniparental lineages, male and female markers passed through the Y chromosome and mtDNA respectively. The general results of these were that both the extreme scenarios of total replacement and pure cultural diffusion are false.
On the one hand Jews across the world by and large share unexpected genetic affinity which one would not predict from geography, but only from their common religious-ethnic identity as Jews.
One of the most popular posts on this weblog focuses on the differences between Ashkenazi Jews and gentiles, in particular peoples of European descent. The figure to the left illustrates that white Americans who are gentile or Jewish are rather easy to distinguish genetically from each other.
That Jews exhibit a particularly distinctive genetic signature may not be all that surprising, considering that medical geneticists have long known that there are diseases which are biologically rooted and heavily overrepresented among this population.
Distinctive traits imply distinctive genes.JSTOR is a digital library of academic journals, books, and primary sources. Evolution and Biodiversity: The evolutionary basis of biodiversity and its potential for adaptation to global change Report of an electronic conference, March We know for sure that Judaism was a dominant religion in the Maghreb at one time, before Islam.
this is false. christianity was the dominant organized religion (though there were certainly jews. BSc (Hons) Genetics.
|Lamarckism - Wikipedia||A phenotypic characteristic, acquired during growth and development, that is not genetically based and therefore cannot be passed on to the next generation for example, the large muscles of a weightlifter. Any heritable characteristic of an organism that improves its ability to survive and reproduce in its environment.|
|The Ionians||Results not replicable   Late 20th century[ edit ] The British anthropologist Frederic Wood Jones and the South African paleontologist Robert Broom supported a neo-Lamarckian view of human evolution.|
|BibMe: Free Bibliography & Citation Maker - MLA, APA, Chicago, Harvard||For a typical small molecule e.|
|Evolution of the bacterial flagellum||Most of them believe that the Earth is only 6 thousand years old, that the Universe was created in 6 days by God.|
|Browse All Topics | The National Academies Press||Results not replicable   Late 20th century[ edit ] The British anthropologist Frederic Wood Jones and the South African paleontologist Robert Broom supported a neo-Lamarckian view of human evolution.|
Investigate the very building blocks of life and delve into the human genome during an exploration of this cutting-edge field. All animals have biological dysfunctions, genetic junk, signs of evolutionary dead-ends and obscure morphologies (birds that can't fly, male nipples, etc) and countless other little imperfections that belie the any idea that evolution 'knows' what it is doing.
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