Franco Manni
|
Razze , razzismo
, traumi culturali, e chiarezza concettuale e ... inconveniens
sulla tolleranza
|
La razza è sinonimo di sottospecie, se tra una specie e un'altra non c'è interfecondità, essa invece c'è tra una razza (sottospecie) e un'altra come si vede nelle razze equine, canine e anche umane. Sono evidenti le divisioni in gruppi della umanità in base alla apparenza religiosa (islam buddismo, etc) , rispetto alla nazionalità cioè lingua (francofoni, arabi, anglosassoni, etc.) m,a è anche evidente la loro divisione rispetto a caratteristiche biologiche (neri, asiatici, mulatti, etc.) Queste caratteristiche biologiche sono appunto le sottospecie o razze della nostra specie homo sapiens... Però a causa della tragedia del nazismo e dell'olocausto, e a causa del razzismo anche successivo e anche attuale, ecco che c'è un trauma morale ed intellettuale nella coscienza Occidentale e questo trauma fa sì che si confonda l'ideologia politica (molto negativa) del razzismo che è un fatto appunto politico, con l'esistenza delle razze, che è solo un fatto biologico. Razzismo significa credere che una razza sia superiore alle altre e che a causa di questa presunta superiorità possa permettersi di levare alle altre diritti e al limite perseguitarle. Razza significa che un insieme di individui posso esser raggruppati tra loro per somiglianze somatiche che li accomunano tra loro più che con altra individui. Quali caratteristiche? Non sono quelle degli organi interni tipo pancreas o composizione del sangue etc, ma quelle esterne, visibili, che colpiscono a prima vista: come colore della pelle, forma del naso, glabrità o pelosità della pelle etc. Coloro che - assurdamente - negano l'esistenza delle razze ( e dunque di queste differenti caratteristiche di raggruppamento ), certamente non riusciranno mai a convincere la gente comune ai cui occhi tali differenze sono evidenti e non scompariranno mai. Ma commettono il grave errore sia intellettuale sia morale di dare questo messaggio alla gente: per affermare che tutti gli uomini hanno eguale dignità e dunque devono avere eguali diritti, bisogna affermare che essi siano eguali nelle loro situazioni materiali e di fatto... … ma questo è un grave errore, perchè la eguale dignità deve essere riconosciuta non se siamo eguali (tutti cristiani, tutti eterosessuali, tutti sani , tutti fascisti, tutti dello stesso gruppo biologico)!!!. essa uguale dignità deve essere riconosciuta proprio quando vediamo che materialmente , economicamente, linguisticamente per opinione politica, per fede religiosa, per caratteristiche somatiche, per orientamento sessuale NOI SIAMO DIVERSI. Uguale dignità morale e giuridica, nonostante le differenze materiali e sociali!!! Altrimenti sparisce lo stesso concetto di tolleranza. Infatti è assurdo dire che si esercita la virtù della tolleranza verso chi è uguale a te per religione, classe sociale, nazionalità etc , essa la si esercita proprio0 verso chi è diverso da te! Se proprio non si vuole urtare la malata ipersensibilità di queste persone snob che negano l'esistenza delle razze, si usi pure un altra parola (gruppi biologici, sottospecie, classi genetiche … che so!)... però è un errore intellettuale e morale negare la realtà! Allego due documenti sulle esistenza delle razze, entrambi molto autorevoli: 1)
il primo è la voce "human races" dal CD 1997 della Encyclopedia
Britannica, cioè la migliore enciclopedia del mondo;
|
|
© Encyclopedia Britannica – 1997 GENETICS OF RACES AND SPECIES DIFFERENCES Arthur
Robinson, M.D. Professor of
Biochemistry, Biophysics, and Genetics and of Pediatrics, University of
Colorado, Denver. Senior staff member, National Jewish Center for Immunology
and Respiratory Medicine, Denver. Francisco
Jose Ayala. Donald Bren Professor of
Biological Sciences, University of California, Irvine. Author
of Evolving: The Theory and Processes of Organic Evolution and others. Russell
Howard Tuttle. Professor of
Anthropology, University of Chicago. Author of Apes of the World: Their
Social Behavior, Communication, Mentality and Ecology. The
nature and origin of R A C E S
and species are dealt with in
the article EVOLUTION, THE THEORY OF, particularly in the section
Species and speciation. Here it is necessary to consider only the genetic
composition of the R A C E and species differences in sexually
reproducing and outbreeding organisms. In
general, species are considered to be populations of organisms between
which breeding is impossible or significantly limited under natural
conditions. Subgroups of an individual species with distinctive
phenotypes form R A C E S, members of which can interbreed with members of other
R A C E S of that species. The geneticist Curt Stern defined a R A C E as a
group more or less isolated geographically or culturally who share a
common gene pool and who, statistically, are somewhat different at some loci
from other populations. In
naturally occurring populations a species may split into R A C E S because
of a gradual geographical separation and eventual rift between formerly
interbreeding groups. Such R A C E S, which inhabit different territories,
are called allopatric. If these R
A C E S are brought together, they assume a
sympatric status, interbreed, exchange genes, and fuse into a single
genetically variable population. R A C E S of human beings and of
certain parasites are exceptional because they can coexist, at least for a time,
sympatrically. In humans, social rather than geographical or biological
factors slow down interbreeding and R A C E fusion. Distinct species
may, on the other hand, be either allopatric or sympatric. The exchange of
genes between species populations is prevented not only by geographic
distance (as with R A C E S) but also by genetically based reproductive
isolating mechanisms. Reproductive
isolation is achieved by a variety of means: differences in preferred
habitats, in breeding seasons, in sexual attraction and courtship rites,
in sexual structures (flowers in plants and genitalia in animals);
incompatibility of sex cells; inviability of the hybrid progenies;
sterility of the hybrids; and weakness of the gene recombination products of
the gene complements of the species. R A C E differences are more often quantitative than qualitative; racially distinct populations of a species differ usually in the frequency of certain genes rather than the presence or absence of certain genes. Studies
on human blood groups have revealed
some instructive situations. As discussed earlier, the four "classical"
blood groups O, A, B, and AB are due to three alleles of a gene. Most
human populations have individuals of all four types, and even parents and
children, as well as brothers and sisters, may belong to different
blood groups. However, some blood groups, and hence the gene alleles that
produce them, are more frequent in some countries than in others. The
gene for A blood, for example, increases in frequency from east to west
in Europe; B blood is most frequent in some populations of India, Tibet,
Mongolia, and Siberia. A majority of American Indians apparently had,
before the arrival of Europeans and Africans, the O blood group only;
however, the tribes of the Blackfoot
and Bloods had the highest known frequencies of A blood, which is also very
frequent among the Lapps in northern Europe (see also BLOOD: Blood
groups). Human R A C E S differ certainly in many genetic
traits, not in blood groups alone. Some theorists, imagining the human population
as it might have been about 4000 BC, have speculated that there were perhaps
five major R A C E S, one for each inhabited major landmass. The
major human R A C E S are separated by their most readily recognized
characteristics, such as skin colour, body size, and facial morphology.
In modern times many of the barriers, both geographic and cultural, between the
R A C E S have weakened.
Since most of the external differences between R A C E S are polygenically
and environmentally determined, interracial matings produce offspring
that, in general, have a phenotype intermediate between those of the parents. Of the total number of loci existing in the human
species, numbering at least 100,000, the majority of their alleles probably
are present among the members of each R A C E. Although
one population of alleles--for example, those for dark skin colour--may be
common in one R A C E and rare in another, each particular skin-colour
allele occurs in both R A C E S. In fact, studies involving many
polymorphic loci (loci with two or more alleles occurring with a frequency
of at least 1 percent) have revealed that the allelic diversity among
individuals within a single R A C E is greater than that between R A C E S.
Intelligence is a highly variable characteristic that some have
claimed varies among different human R A C E S. This characteristic is
difficult to define and even more difficult to measure. In addition, it is
significantly influenced by environmental factors. Finally, the trait
certainly varies more within members of a R A C E than between R A C E S. R
A C E S are genetically open systems, and gene exchange between R A C E S
does take place. Species, by contrast, are genetically closed systems
in which gene exchange is rare or absent. R A C E differentiation is
reversible; hybridization or intermarriage may cause R A C E S to merge
into a single population. It is an error to think that in a population
resulting from R A C E hybridization all individuals will be alike; in point of
fact, such hybrid populations show a remarkable diversity of individuals.
Species differentiation is irreversible. R
A C E S are populations, and an individual may have a genetic endowment that
can occur in two or more different R A C E S or that is not common in
any R A C E. An individual belongs, however, to only one species, unless
that individual is a species hybrid.
Mules, hybrids between the horse and donkey, are sterile because of
abnormalities in the processes of sex-cell formation in their gonads.
Sterility of hybrids between species, if viable hybrids between them
can be obtained at all, is observed very frequently, though some
experimentally obtained species hybrids have proved to be fertile. Scientists
have asked what causes the development of the gene-frequency differences
between populations that live in different territories, or, in other
words, what makes these populations racially distinct. The probable explanation is that genetic differences
between populations arise in most cases through natural selection in
response to the local environments that prevail in the territories they
inhabit. It is, however, very difficult to verify this explanation in many
concrete instances of R A C E differentiation. For example, it is
probable that the dark skin pigmentation of many human populations that
live, or have until recently lived, in tropical and subtropical
countries protects them from sunburns. It is probable also that the light
skin colours of the natives of Europe facilitate the acquisition of
vitamin D in regions with deficient sunshine. The
evidence for even these hypotheses is not as conclusive as might be
desired. But when it comes to such racial traits as hair form and shapes of
the nose, of the lips, and of the cheekbones, no acceptable evidence of
adaptive significance is available. The situation is no better with R A
C E S of animals and plants: for most racial differences the adaptive
significance is unknown. Attempts have been made to envisage
factors other than natural selection that could be responsible for genetic
differentiation of populations. Appeals are frequently made to
pleiotropism of the gene action; a visible R A C E difference may in itself
be neither adaptive nor unadaptive, yet it may be only an outward sign
of an underlying physiological difference that is adaptively important.
An elegant example is the coloration of onions--red and purple bulbs are
resistant to the attacks of a smudge fungus, while white bulbs are
highly susceptible. A R A C E trait may also be important as a sexual
recognition mark, or it may play a role in the courtship ritual. A
most interesting possibility that should be seriously considered is that
some differences between populations may be due to random
genetic drift. As was discussed above, genetic drift acts on small
populations. Suppose that a species lives in many
isolated colonies, some of them consisting of only tens or perhaps
hundreds of individuals. Chance events may cause the gene frequencies
in the different colonies to drift apart. How important this random genetic
drift may be in R A C E differentiation is controversial. That genetic
drift does occur is certain; a simple example is that in small villages a
sizable fraction of the inhabitants sometimes have the same surname,
and different surnames are frequent in different villages. Increasing
or decreasing frequencies of the surnames evidently go together with
increases or decreases of the frequencies of certain genes that the
ancestors of the people with these surnames carried. As discussed, genetic
drift can also arise from the founder effect. When the populations of
new colonies founded by a small number of individuals expand, they will be
found to differ genetically from each other and from the ancestral
population. Natural selection will then come into operation, giving rise to
new balanced gene pools. The founder
effect was probably important in the development of some human populations.
Many tribes and local R A C E S may be the descendants of small numbers of
original migrants and settlers. Whether the random genetic drift alone
can explain the origin of the gene complexes that differentiate R A C E S or
species is very doubtful. The point is, however, that genetic drift and
natural selection are not mutually exclusive alternatives; it is not one or
the other but the interaction of both that brings about R A C E
differentiation. The founder effect is a special case of random genetic
drift. The gene pool of a colony derived from a single immigrant or
several pairs of immigrants may need a restructuring by natural selection
to become properly adapted to the new environment. Human
Evolution R A C E AND POPULATION Definitions and
terminology. The
term R A C E as applied to humans has been variously used--by politicians,
military leaders, philologists, human biologists, demographers, and
historians. Some "R A C E
S" constitute language groups, often of peoples whose only kinship is
that they speak a common language. Such was the original meaning of the
so-called Aryan R A C E. Some "R A C E S"
are simply hypothetical, invented to embrace present distributions of
such genetic (hereditary) characteristics as stature or hair colour--e.g.,
the Nordics. (The word Nordic also has been given a political meaning,
referring, despite their differences in physical characteristics, to
peoples in northern Europe.) R
A C E has been variously applied to national or cultural groupings, as in
the days when English writers referred to an Irish R A C E and to a
Scottish R A C E. As used in census and other applications, the designation R A C E
often groups different peoples for administrative convenience; thus, the
category Hispanic may group people from Meso-America, the Caribbean,
South America, and the Philippines who may differ considerably in their
racial origins. "R A C E" also has been applied to
human groups inferred to have existed on the basis of archaeological
discoveries; the Etruscan R A C E is an example. Various religious
groups who may or may not have common ancestry sometimes are called R A
C E S--the Jewish R A C E, for example. By extension of biblical thinking
and in honour of Shem, son of Noah, a Semitic R
A C E was conceived in an effort to describe peoples who spoke Semitic
tongues, some of whom may have learned their language more recently
than others. All
of those uses of the term R A C E are separate and distinct from its
biological meaning in classification (taxonomy)--the natural
divisions or groupings below the species level. As such, R A C E differs from breed or line,
which refer to artificially established groups maintained by intensive
selection or by deliberate hybridization. Just as the term R A C E is often
too broadly applied to the entire species of man (as in the human R A C
E), particular R A C E names invented to explain distributions of observable
physical characteristics of human populations are not biologically
meaningful. The
misuse of the word R A C E--particularly the manner in which it was employed
by Nazi Germany--had led workers to search for alternate terms. Some
biological descriptions refer to human stocks, one intention for this
being to avoid political overtones. Other writers have favoured the
word division in lieu of R A C E, again apparently to escape what may be
perceived as offensive connotations. Other references to these human
groupings include strain (without implying the equivalent of purebred strains
of laboratory animals); variety (although the specific botanical
meaning does not apply to human R A C E S as ordinarily constituted);
and ethnic group, which, although generally meaning cultural or
political groupings (e.g., Macedonians, Croats, Magyars, or Slovenes),
is at times used with exactly the same biological meaning as R A C E. With
the advent of population genetics, establishing gene frequencies in
specific populations, many
workers have come to prefer the word population for taxonomic
purposes. Populations so defined, however--such as San (Bushman), Ainu, Lapp,
Eskimo, Coloured (South Africa), or Micronesian--are often the same
groupings that have been or can be called R A C E S. Still, population is a
useful addition for such linguistically and genetically distinct groups
as the Basques and is an easier concept to explain. The
term geographic, or continental, R A C E is often used to describe
populations that occupy a broad geographic range. Likewise, local R A C
E is used for populations in a more restricted area, and microR A C E may
correspond to a single, extended breeding population. These natural
groupings, which reflect geographic (and therefore reproductive) isolation,
display a range of genetic differences that are the focus of much
research. The ultimate questions are how long the R A C E S (or populations)
have been distinguishable and what processes brought about the
distinctions. What the different geographic R A C E S are called
is to some extent unimportant as long as the same terminology is employed by all;
such traditional designations as white, yellow, and black, however, are
clearly inappropriate. The designations for local R A C E S and microR
A C E S are similarly unimportant, except for communication and for the
sensitivities of the people themselves. It has long been a practice on
the part of some human taxonomists to convert place-names into taxonomic
names by adding the suffix -id (e.g., Pennsylvanid, Montanid) or the
suffix -oid (Capoid for the Cape peoples of South Africa). Geographic terms, without
suffixes, also suffice (hence, the Mediterranean R A C E) or are used in
conjunction with language groupings, where justified (e.g.,
Azteco-Tanoan). Often reference is made to particular national or cultural
groupings, such as Finns, because available data are so arranged, or to
artificial groupings (e.g., Ghanaians or Vietnamese) until further
information can establish more precisely the makeup of those groups.
Even a designation as being from a city may not be enough, given demographic and
genetic differentiation within cities, Tokyo being a typical example. Human
Evolution Geographic R A C E S. Naturally occurring (i.e., produced by natural,
usually geographic separation
of human groups) R A C E S of the human species are by no means
identical in number of members or degree of genetic differentiation. There
are small groupings of a few hundred to a few thousand individuals,
some slightly and only recently isolated reproductively from adjacent
people. Other equally small groups may have been mating apart from the
rest of mankind for centuries or even for thousands of years. Members
of some human R A C E S number in the hundreds of millions (as the peoples
of modern Europe) or in the billions (as in Asia). It
is both useful and meaningful to identify the very large human groupings
that often correspond to continents or other major geographic areas as
geographic R A C E S, a term extensively used with other life forms.
Geographic R A C E S are numerically large, containing within them
smaller groups of reproductive isolates (breeding populations). The reasons
for the large groups' geographic delineation are usually clear. The
Indians of the Americas were
reproductively separated from the peoples of other geographic regions
for many thousands of years. Thus, they have come to differ genetically from
the rest of mankind and even from those Asians from whom they stemmed.
The Australian Aborigines
similarly constitute a geographically defined group of local R A C E S
(see below) separated for millennia from the rest of the world, except for
some slight contact, until the late 18th century. Human
Evolution The antiquity of Homo sapiens. It is a
curious fact that, although evidence for the evolution of man is extensive,
direct fossil evidence of the earliest members of the species Homo
sapiens is relatively scarce. The species H. sapiens (of which the modern
human R A C E S comprise a number of different geographic varieties)
may be defined in terms of the anatomic characters shared by its members.
The definition for prehistoric representatives of the species must be
limited to skeletal characters, the only remains to be found, and includes
such features as a mean cranial capacity of about 1,350 cubic centimetres
(82 cubic inches), an approximately vertical forehead, a rounded
occipital (back) part of the skull with a relatively small area for the
attachment of the neck musculature, jaws and teeth of reduced size,
small canine teeth of spatulate form, the presence of a pointed or
projecting chin, and limb bones adapted to a fully erect posture and
gait. Any skeletal remains that conform to this pattern to an extent that
precludes classification in other groups of higher primates must be
assumed to belong to anatomically modern H. sapiens. In the past there
was a tendency to create entirely new species of Homo on the basis of
fragments of prehistoric human skeletons, even though the remains
showed no significant differences from modern man. This tendency was
prompted by the supposed antiquity of the remains or by a failure to
realize how variable some features are even in modern man. The species of
the genus Homo that immediately preceded H. sapiens was H. erectus, and
it is most likely that sapient humans (H. sapiens) evolved from H.
erectus.
|
Franco Manni indice degli scritti
|
Maurilio Lovatti main list of online papers
|