How did Darwin define race?

Discussion in 'Biology & Genetics' started by Medium Dave, Feb 8, 2017.

  1. rpenner Fully Wired Staff Member

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    1) Citation required. You are (twice now) citing a specific study and those numbers don't mean anything without details as to which alleles were looked at.
    2) https://en.wikipedia.org/wiki/Human_Genetic_Diversity:_Lewontin's_Fallacy
    Because Edwards calls it a fallacy doesn't make "human race" of biological importance.
    3) Different studies clearly indicate that humans have very little genetic variance compared to the genetic variance within populations of great apes, so you have not supported the claim that "human race" is of biological significance. Indeed, nowhere have you offered an estimate of how many human races there are as the finer you go, the blurrier the application of stereotypes to individuals goes and the more corner cases exists as outgrip marriage is a thing.
    4) Your claim is refuted as inadaquately sourced. “The genomes of a pair of orangutans, for example, differ in more than in more than 2 of every 1,000 base pairs, compared to 1 in every 1,000 base pairs between two humans.” Combine that with the chimp-human distance of about 18 differences per 1000 base pairs and its game over.

    https://www.upf.edu/cexs/news/genetica.html
    http://www.nature.com/nature/journal/v499/n7459/full/nature12228.html
     
    Last edited: Feb 10, 2017
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  3. Medium Dave Registered Member

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    • Making legal threats against forum is discouraged.
    The fact that similar variation ratios are found between species does make your posts BS though.

    Don't worry! You can describe yourself as an expert. It's the internet! Pretend to be whatever you want. Lie, cheat. You're anonymous!

    I wonder if I can have this board investigated for public disservice.
     
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  5. spidergoat Valued Senior Member

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    Biologists had estimated that two individuals would be identical in 99.9 percent of their DNA, but the true figure now emerges as much less, around 99.5 percent, Dr. Scherer said.

    http://www.nytimes.com/2007/09/04/science/04vent.html
     
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  7. Fraggle Rocker Staff Member

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    I was delighted to ignore all the posts by Mediocre Dave, which the Moderator has so kindly identified as worthless. But somewhere in those 3 or 4 pages I noticed that someone else had written that the various "races" of Homo sapiens should be called "species."

    This is astoundingly incorrect. Homo sapiens IS a species. Distinct populations within a species are called "subspecies." For example the original wolf's species is Canis lupus, but the wolves who abandoned the pack to hang out with humans (if only because what we call "garbage" lying around our camps is what the wolves call "free food"), after 20,000 years of separation, are now the subspecies Canis lupus familiaris.

    This vocabulary is used for all living things, with one single exception: We call distinct populations of Homo sapiens "races" instead of "subspecies."

    Frankly, there's really nothing wrong with that, because the genetic difference between an Eskimo and a Somali is less than one percent, far below the bar normally used to distinguish subspecies. It makes sense to distinguish a "race" from a "subspecies," but unfortunately the word "race" has fallen on hard times and cannot be used in all discussions of genetics.
     
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  8. iceaura Valued Senior Member

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    No, we don't. The entities called "races" in human beings do not have the biological status of subspecies, in any extant sociological "race" classification system. The "black" race in the US and similar Western European cultures, in particular, is not a subspecies, biologically. It is not even close. It is not a biologically coherent entity.
     
  9. iceaura Valued Senior Member

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    24,086
    And neither one of those is a "race", in any racial classification system I know of. When referring to them, in particular, we in the US say "Eskimo" and "Somali", and if we mistake "Inuit" for "Eskimo" and "Sudanese" for "Somali" we correct ourselves upon becoming better informed.
    None of the current racial classification systems even approach that usage, or approximate that distinction. They are not biologically motivated, and their alignment with biological race is a matter of accident or coincidence.
     
  10. exchemist Valued Senior Member

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  11. iceaura Valued Senior Member

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    It's worth emphasizing, cherry picking from the minor clauses and side comments buried in there,

    not denying anything but changing emphasis,

    that two separate and quite distinct objections to a claim of biological or "scientific" racial classification exist: 1) it's impossible, we're all one 2) it hasn't been done.

    I'm claiming '2' is the case.
     
  12. exchemist Valued Senior Member

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    Yes exactly. It's a vague sort of a thing, traditional and physically "obvious" in a superficial sense, yet when you try to pin down a scientific basis for it, it slips through your fingers, because it isn't fundamental enough to correlate with anything much. Or that's the impression I get from the article.
     
  13. iceaura Valued Senior Member

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    Side comment: genetic "variation" among organisms is an ecological category diversity, a combinatorial measure, not a range on a continuum. It's digital, not analog, and it's hierarchal - not all "single digit" differences are equivalent.

    Illustration: One's diversity measure must account for the fact that a five count difference in chromosome number is far more "variation" than a five count difference in the amino acid sequence along a code stretch that produces hemoglobin.

    So in classifying human beings by genetic "race", the various and sophisticated techniques found necessary in quantifying ecological diversity will necessarily come into play (as they have, in some of these studies), and it's not going to be easy.
     
    Last edited: Feb 10, 2017
  14. rpenner Fully Wired Staff Member

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    If it is currently accepted that humans exhibit subspecies rather than just a pattern of trait distributions due to a branching and occasionally recombining contingent history of population splits and moves, then there should be some current, widely accepted biology reference which enumerates them.

    My reference was newer and sourced to more than one sample.
    Venter's 2007 article is here: http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.0050254

    Try as I might, I could not find a recent respected authority which estimated "average nucleotide diversity" across the global population. Part of the problem is most of the methods used are scattershot methods which trade speed for absolute fidelity. Part of the problem is that this global measure is less interesting than current research topics. But in animals ...

    https://web.natur.cuni.cz/zoologie/...Determinants-of-genetic-diversity_NRG2016.pdf uses figure 2c from
    http://www.nature.com/nature/journal/v515/n7526/abs/nature13685.html

    From 2004:
    http://www.nature.com/ng/journal/v36/n11s/full/ng1438.html
    Some argue that there is no such thing as 'race' or that it is biologically meaningless. Yet the lay person will ridicule that position as nonsense, because people from different parts of the world look different, whereas people from the same part of the world tend to look similar. The popular concept of five races corresponds well to both geographic regions (Africa, Europe, East Asia, Oceania and the Americas) and bureaucratic definitions (e.g., the US census bureau; http://www.census.gov/population/www/socdemo/race/racefactcb.html). In this review, we focus on the biogeographical distribution of genetic variation and we address the question of whether or not populations cluster according to this popular concept of 'race'. We show that racial classifications are inadequate descriptors of the distribution of genetic variation in our species.

    ... for populations from geographically intermediate regions (e.g., Central Asia, the Middle East), in which individuals had partial membership in multiple clusters, especially those of flanking geographic regions, indicating a continuous gradient of variation among some regions. Thus, although the main clusters correlate with the common concept of 'races' (as expected, because populations from different parts of the world have larger differences in allele frequencies than populations from the same region of the world), the analyses by STRUCTURE do not support discrete boundaries between races. ​

    Also: http://www.nature.com/ng/journal/v36/n11s/full/ng1435.html
     
  15. iceaura Valued Senior Member

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    Much as one approaches genuine professional expertise, as an amateur, with humility, it has to be pointed out that this correspondence they point to is a kind of illusion, not due to "intermediate" regions alone, and easily deceptive

    That one can somehow find and delimit five regions of the globe, and claim to match them with some carefully unspecified five races of Western culture's "popular" classification, is not surprising. But in doing so, they have - for example -
    1) classified Taiwan and Japan not with Oceania but with East Asia for some technically invisible reason
    2) set aside the large (and even predominant) populations of their "African" race (Western "popular") inhabiting Oceania,
    3) apparently taken subSaharan Africa and some of the Horn for "Africa"
    4) apparently omitted or classified as "intermediate" SE Asia, India, most of Central Asia, and the entire Asian landmass north of the Himalayas - a very large population and area of the planet to omit, and not geographically "intermediate" in any useful sense.
    5) misdescribed (or ignored) the five racial classifications currently extant in the US, since "brown" is one of them (black, white, red, yellow, brown) and "Oceania" has no single US associated race.

    And so forth.

    Their intention is clear, and fine, and hard to disparage - but imho this approach and expression tends to obscure the basic and all-important (in the US) fact: the US racial classifications are incoherent garbage, biologically. Nothing can be biologically argued from them with confidence.
     
  16. rpenner Fully Wired Staff Member

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    The last line of the paragraph you quote from agrees with you, as does the second paragraph I quote from that 2004 article.
     
  17. iceaura Valued Senior Member

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    Yeah, I'm just gunshy of the rhetorical approach, even addressing the choir as Nature probably assumes it is - don't bury the lede, in this matter, is my reaction.

    Some headline like "All your races are belong to bullshit", first thing, elaboration of "structure" later. But that's probably from hanging around the wrong places.
     
  18. Kristoffer Giant Hyrax Valued Senior Member

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    Whoever got rid of Bigger than small Dave, I thank you.
     
  19. Yazata Valued Senior Member

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    We should recognize that the word 'species' has never been precisely defined in biological science.

    https://en.wikipedia.org/wiki/Species_problem

    Most textbooks speak of species in terms of the ability to mate and produce fertile offspring. That definition was invented (or at least popularized among biologists) by Ernst Mayr in the 1940's. But there are other ways of defining species in use.

    Historically species were defined morphologically, by physical appearance, and many species definitions today are still based on that. And there are quite a few morphologically defined species such as different species of bears that are reproductively isolated due to geography but are known to successfully mate when brought together in zoos or wherever. (And hence might be better described as 'subspecies', but are still called 'species' for historical reasons.)

    In paleontology, including human physical anthropology, it isn't possible to directly observe mating and its success, so species attributions are typically morphological, based largely on the shapes of fossil bones and other hard parts.

    In non-sexual organisms like bacteria that often appear identical to the naked eye (tiny spheres and cylinders) species attributions are typically functional, based on biochemistry and what kind of fermentations the bacteria can perform, or whatever the defining biochemical ability happens to be.

    In the quote in the OP Darwin seems to have suggested what might arguably be yet another criterion for species, namely common evolutionary descent. (This is the basis of contemporary cladistic classifications, though it might arguably be more applicable to higher taxa.) As plausible as it sounds, evolutionary descent can't be directly observed and needs to be reconstructed, and those reconstructions are typically based on morphological characteristics.

    I agree with that, while recognizing that the word 'species' isn't precisely defined.

    In zoology, 'subspecies' is the only internationally recognized sub-specific taxonomic category. (In botany, there are several.) It's even less clearly defined than 'species', though in zoology it typically refers to recognizable variants that can mate successfully with other variants but typically don't due to geographical separation or whatever.

    I think that's more of a cultural decision than a biological one. And more recently it's become tremendously politicized. Issues of race have become identified with issues of good and evil, so definitions of 'race' have become tremendously fraught.

    I think that recognizable geographic variants in the human species might justifiably be called 'subspecies' based on how that word is used with other animals. These categories do seem to be awfully blurry at the edges of human populations though, where there's increased opportunity for contact with different populations. I expect that we would observe that with animal subspecies too, if they came into contact and intermixed on a large scale. That intermixture of human varieties seems to be increasingly common as world travel and international migrations occur. Geographical reproductive isolation has broken down, at the individual level at least. It might still be more visible in averages over large geographically separated populations though, since mating in a population is still typically with locals who can be expected to be more similar than distant individuals from different populations. So these kind of categories possess a sort of momentum.
     
  20. Fraggle Rocker Staff Member

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    Well yes. I thought I had made it clear that I agree with your statement. Please forgive me if I did not.
    Indeed.
    And, of course, there is none.
    And of course this illustrates the difference between a scientist and a layman!
    Over the centuries, they have been used predominantly to support the notion that members of the various "races" have different levels of intelligence, ambition and trustworthiness. Over the last few decades, the discussion has become somewhat more concerned about the conditions in which various populations have been living, notably their opportunities for education, health care, safety and employment. Yet a large portion of our population still believe that people of African descent are not as intelligent, trustworthy or motivated as the rest of us, and almost as many feel the same way about people of Latin-American descent.

    But you can't win for losin' in this country. The Jewish people have always prided themselves on their educational standards and their work ethic, yet anti-Semitism is still the most common form of ethnic hatred and distrust in the USA and even in Europe. This would be amusing in another context, because when a group of them traveled east to escape the pogroms, the Chinese people found their sense of ethics and honor to be virtually identical to their own. They were welcomed without fanfare, and found themselves so well-accepted that they simply merged into the Chinese gene pool. There are still a few ancient synagogues in China. I don't know if they are treated as museums or have been put to more practical use.
     
  21. iceaura Valued Senior Member

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    24,086
    A Pratchett fan? RIP all of the Jocks.
     
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  22. Galtonian Registered Member

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    He found that the majority of the total genetic variation between humans (i.e., of the 0.1% of DNA that varies between individuals), 85.4%, is found within populations, 8.3% of the variation is found between populations within a "race", and only 6.3% was found to account for the racial classification.

    https://en.wikipedia.org/wiki/Human_Genetic_Diversity:_Lewontin's_Fallacy
     
  23. Galtonian Registered Member

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    You appear to be unable to do arithmetic.

    Sewall Wright's fixation index FST measured among samples of world populations is often 0.15 or less when computed as an average over many alleles or loci. To many, this result indicates that the genetic similarities among human populations far outweigh the differences. For example, a finding like this led Richard Lewontin to claim that human races have no genetic or taxonomic significance (Lewontin 1972). Despite the far-reaching proclamations that researchers make from FST, few have questioned the validity of how it is applied or interpreted. Earlier in this decade, Rick Kittles and I took an unusually critical look at FST (Long and Kittles 2003). We analyzed a unique data set composed of short tandem repeat (STR) allele frequencies for eight loci genotyped in both humans and chimpanzees (Deka et al. 1995). These data made it possible to see how FST played out when no one could dispute taxonomic and genetic significance. The answer surprised us. FST was pretty close to the canonical 0.15 shown so many times for human populations. In our analysis, FST was 0.12 for humans, but for humans and chimpanzees together, FST rose only to 0.18.

    https://www.researchgate.net/public...of_Biological_Races_2003_Fixation_on_an_Index

    What are you even going on about? There is no threshold on taxa validity. It's fabricated to deny race.
     

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