Do animals have haplogroups

Genetic research: our family

Anyone who talks about Europe is moving roughly. One reason is the continent's chronically mobile borders: wars and cartographers have always pushed them back and forth quite arbitrarily, whereby a supposedly natural geographical barrier was always a matter of negotiation. For example Cyprus: The outcome of the war between the Ottomans and the Philohellenes in the 19th century laid the foundation for the later EU membership of the southern part of the island - not the strait of the Bosphorus, which would end Europe further to the west. And the most western island: is it Ireland or is it Iceland? The eastern border - the Urals? The mountain range won and lost its status several times: sometimes Europe reached deep into Siberia, sometimes as far as where Poland just came into being (or disappeared) - depending on the degree of suitability for Europe that the spirit of the times might ascribe to the Russian people.

So we live in a very changeable Asian subcontinent. And who is it then, "we"? What, if not a precisely defined homeland, makes "us" Europeans - and possibly typical? Is it perhaps our family tree, i.e. our genes?

  1. Europeans, Africans and Asians are so genetically similar that they cannot be meaningfully divided into clearly defined large groups.

  2. (Pre) history has constantly mixed up the ethnic groups of Europe, so that all Europeans have many common genetic ancestors, some of which lived in the more recent past: In Europe there is an extended family with close cousins ​​on all parts of the world.

  3. Only a few gene variants are "European". You determine the appearance of your hair and skin, or your tolerance to certain foods, such as milk.

  4. Gene analysis techniques that take into account as many different genome communities as possible can still identify age-old substructures in the European population. They provide clues to the millennia-old history of settlement and mixing.

This article is contained in Spectrum - Die Woche, KW 22, 2013

Biologists have been searching for "European genes" for a long time. And for just as long, the question also attracts biological ideologues, who selectively pick out suitable set pieces from the new scientific findings: They are looking for a "European race" that is characterized by these special genes. But: do these genes even exist?

Scientists are at least unanimous on the question of "race" - it is no longer used as a classification category. The reason for the rejection of the term is not a politically correct use of language: In fact, the total genetic variability of human ethnicities is always too great to be able to distinguish one "race" from another in a meaningful way (see text box). However, this does not mean that there are no differences between individual groups of people - and sometimes even clearly noticeable. There are certainly reasons to use the scientifically meaningless label "race" - modified to include ethnicity or the like - in a certain context as a useful drawer for people with common, arbitrarily chosen characteristics. For the purpose of quick external identification, a typical Northern European with white skin is still defined by the US immigration authorities as a "Caucasian type".

Caucasian outward appearances

The typical outward appearances of the phenotype "Caucasian" - that is, the European prototype, which today also makes up large parts of the population in America, Australia, North Asia and Europe - are of course caused by certain gene variants: Variants that decide whether he is more often blond or red-haired, blue-eyed and white-skinned as people in Asia and Africa.

People and races

Scientists have been avoiding the label "race" for some time in order to identify subcategories within a species - that is, to form subgroups of individuals who differ from others in subjectively determined genetic or external characteristics. Precisely because this categorization takes place according to arbitrarily determined conventions, it is - except for the characteristics used for the categorization - not meaningful.

The term is still used in animal breeding, but here too the problems of the concept come to light. Take horse breeds, for example: they are sometimes so subtly defined on the basis of a few characteristics that in the end sometimes the offspring of an animal would have to be counted as belonging to a different breed than its parents by definition. Scientists agree about the absurdity of defining concrete human "races": everyone living today homo sapiens is too closely related to any other human being.

Of course, "races" - or ethnicities or population groups - can be grouped arbitrarily on the basis of some common, for example external characteristics: hair and skin color or the shape of the nose distinguish the average Nigerian from the Finn in a striking way. A look at the entire DNA sequence - instead of just the few gene variants that influence the randomly selected characteristics - proves that two individuals from two different such population groups can be genetically much more similar than two people of the same ethnicity.

A more sensible drawer than the conventionally formed "race" on the basis of external appearance and geographical distribution are direct kinship lines. They are also of great interest to medical researchers who want to develop "ethnic drugs": active ingredients against diseases that occur in certain related large groups occur more often. Examples are Tay-Sachs disease, which is common in the ancestral line of the Jewish Ashkenazim - or sickle cell anemia, which affects people of West African origin more often. In most cases, sorting into traditional races, for example by skin color, does not give any real clues as to a risk of disease - but a closer look at the ancestors of those affected. What applies to all ethnicities also applies to these kinship groups: the variability of all genes within the group is so high that individual members can differ more than from a "stranger" who lives remotely.

For example, a few "European gene variants" - or better, European mutations in all kinds of different regions of the genome - decide on the color of the skin: The Caucasians - unlike phenotypic Asians - become lighter-skinned, among other things, due to selective changes in three genes, the all play a role in the production of the dark skin pigment melanin [1].