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2.1: Scale, Human Space, Powers of Ten for Physical Anthropology

  • Page ID
    5006
  • [ "article:topic", "authorname:aschoenberg" ]

    Anthropology is a broad field that incorporates many sub-fields and borrows from many other disciplines, so the space that is relevant to physical anthropology is also vast. It ranges from the atomic particle that causes genetic mutation—the primary cause of evolution—to the plasticity of the human body because of our need to adapt to seasonal changes caused by the elliptical orbit of the planet in the solar system. Anything bigger or smaller is beyond the scope of physical anthropology. Why atomic particles behave the way they do is a question of physics. Whether life exists on other planets is a question of astrobiology. Both are good themes for philosophy and science fiction, but are beyond the scope of this class.

    Meters Common Measurement Abbreviation Relevance
    10 -10 1 ångström 1 Å Size of an atom
    10 -9 1 nanometer 1 nm Diameter of DNA helix, size of a base
    10 -8 10 nanometer 10 nm Size of a codon (3 base pairs)
    10 -7 100 nanometer 100 nm Locus, length of a typical gene
    10 -6 1 micron 1 µm Cell nucleus,Plasmodium falciparum
    10 -5 10 microns 10 µm Typical primate cell
    10 -4 100 microns (micrometer) 100 µm Patch of melanin, width of hair, human egg
    10 -3 1 millimeter 1 mm The height of a cusp on a Y-5 molar
    10 -2 1 centimeter 1 cm Human ear bones,Anopheles mosquito
    10 -1 10 centimeters 10 cm Length of a human's opposable thumb
    10 0 1 meter 1 m Space that an individual primate occupies
    10 1 10 meters 10 m Typical sleeping area of a primate social group
    10 2 hectare/ 2.5 acres, football field 100 m Typical core area of a primate social group
    10 3 10 hectares, 1 kilometer 1 km Typical territory of a non-human primate social group
    10 4 100 hectares 10 km Typical home range of a non-human primate social group
    10 5 100 kilometers 100 km  
    10 6 1,000 kilometers, continent 1000 km Typical range of a non-human primate species; range for most of human evolution
    10 7 10,000 kilometers, the surface of the planet Earth 100000 km The range of all biological evolution
    10 12 1 billion kilometers, 1 terameter 1 Tm The Earth's orbit in the solar system, includes meteors and solar radiation

    Notice that most of the larger ranges are relevant for hominid evolution and primate behavior, the medium sizes are used in osteology and to compare human and hominid variation. The smaller sizes can describe human variation and genetics. Refer back to this chart as we cover those relevant sections.

    Exercise \(\PageIndex{1}\)

    Use this chart and watch the movie POWERS OF TEN

    “Recognize that the very molecules that make up your body, the atoms that construct the molecules, are traceable to the crucibles that were once the centers of high mass stars that exploded their chemically rich guts into the galaxy, enriching pristine gas clouds with the chemistry of life. So that we are all connected to each other biologically, to the earth chemically and to the rest of the universe atomically. That's kinda cool! That makes me smile and I actually feel quite large at the end of that. It's not that we are better than the universe, we are part of the universe. We are in the universe and the universe is in us.”
    -Neil deGrasse Tyson

    Note

    More on scale and measurements: human scale

    Imagination Question

    When you look in the mirror do you see yourself as a trillion cells, or a trillion, trillion atoms which came from stardust, or a collection of selfish genes, or an individual?