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Comprehensive Study Notes: Evolution and the History of Biological Anthropology

History of Evolutionary Theory and Course Context

  • Evolutionary theory overview in this course: history, key figures, concepts, and contemporary discussions.

  • Today’s plan includes: History of Biological Anthropology; Multi-Media Article Discussion; What Does Evolution Mean to You?; Origins of Evolutionary Theory; Darwin and His Influences; What Does Evolution Mean to You Now?

  • Important upcoming items and deadlines:

    • Check-in Question due at 3pm on Thursday

    • Multi-media assignment #1 due at midnight

  • Science as a discipline: Science is both a body of knowledge and a methodology, characterized by hierarchical organization and progressive/incremental advances.

    • Key features highlighted: Hierarchical science; Progressive/Incremental progress

Science: Body of Knowledge and Methodology

  • Science defined as both a body of knowledge and a method for acquiring new knowledge.

  • Emphasis on how scientific ideas are built over time, tested, and refined.

Early Pioneers in Biological Anthropology

  • Johann Friedrich Blumenbach (1752–1840)

    • View: static types that did not change over time.

    • Contributions: Craniometry; proposed five racial categories based on skull measurements; foundational for popular notions of race.

  • Samuel Morton (1799–1851)

    • Role: Founder of physical anthropology in the U.S.

    • Methods: Collected and measured over 1,000 crania; published Crania Americana (1839) establishing skull landmarks and cranial capacity measurement.

  • Franz Boas (1858–1942)

    • Title: “Father of American Anthropology.”

    • Stance: Challenged scientific racism and taxonomic racial conceptions; advocated cultural relativism.

  • Aleš Hrdlička (1869–1943)

    • Founding roles: Founded American Journal of Physical Anthropology (1918); helped establish the American Association of Physical Anthropology (1930).

    • Focus: Skeletal studies to understand disease impacts; curatorial work at the NMNH (National Museum of Natural History).

  • Earnest Hooton (1887–1954)

    • Focus: Racial classification; studied convicted criminals for behavioral clues; trained many prominent anthropologists; affiliated with Harvard and the Peabody Museum.

  • Sherwood Washburn (1911–2000)

    • Reorientation: “New Physical Anthropology.” Studied non-human primates and reframed research to emphasize evolutionary dynamics and adaptation within ecological contexts; integrated with evolutionary biology.

Case Study: Lisht Skeletons and Senebtisi

  • 2022 skeletal remains from Lisht, including a known individual Senebtisi.

  • Professional interactions:

    • Met at the Peabody Museum of Archaeology and Ethnology.

    • Remaining skeletal remains were sent to the National Museum of Natural History.

  • Debates between Hooton and Hrdlička:

    • Hooton (Peabody): Requested hair-preserved, mummified individuals; involved in reassembly of Senebtisi’s skull while ribs and other fragments were not fully preserved.

    • Hrdlička (NMNH): Studied skeletal remains to infer admixture in ancient Egyptians; many Lisht remains were disarticulated (about 92.6%).

  • Key data point: Approximately 92.6% of Lisht skeletal remains were disarticulated.

The Conversation Article: Ethical and Epistemic Considerations

  • The Conversation article critiques the collection and use of hundreds of 19th-century skulls gathered under historical medical-science frameworks; it examines who has authority over the dead and how living researchers engage with remains.

  • Contextual details:

    • Publication: November 14, 2024 8:23am EST.

    • Visuals include a depiction of Crania Americana (Samuel Morton) and an Egyptian mummy photo reflecting debates about rights and research ethics.

  • Central questions raised:

    • Who gets to decide what is done with human remains?

    • How do rights of the dead intersect with scientific inquiry and living communities’ rights?

Multi-Media Analysis Prompts

  • Analysis prompts to address for Multi-media Analysis #1:

    • Who is the author(s) of the articles?

    • Who is the intended audience for these articles?

    • How do these articles relate to the discussion on Tuesday (8/26)?

    • Provide two questions the articles prompted for you (

    • Due August 28th at Midnight)

  • The prompts encourage critical evaluation of sources, audience assumptions, and connections to classroom discussions.

Check-in Question: What Does Evolution Mean to You?

  • Check-in question prompt appears as a recurring class activity to gauge personal interpretations of evolution.

Check-in Policy on Check-in Questions

  • Policy note: The three lowest grades will be dropped; use check-ins for attendance.

Core Concept: Evolution

  • Definition: Evolution is the change in allele frequency within a population over time.

  • Formal representation (allele frequency p and q = 1 − p):

    • If the allele frequency changes between generations, i.e.
      \Delta p = p' - p \neq 0,
      then evolution has occurred.

  • This definition frames evolution as a population-genetic process rather than a per-organism change.

Origins and Early Concepts

  • Origins section highlights pre-Darwinian ideas about “Origin” and “Ideal forms.”

  • Scalae Naturae (Ladder of Being): view that organisms can be arranged in a linear scale from simple to complex.

  • Creationism: belief that God created the world and life in its current forms; includes the idea that changes since creation have been limited or non-existent.

  • The slide contrasts organized scale and creationist views with emerging ideas about change over time.

Global Context and 19th–20th Century Geography (Visual Slide)

  • A broad map illustrating exploration, colonization, and imperial networks; emphasizes that scientific ideas about human variation arose within historical contexts of global exploration and contact.

Uniformitarianism and Stratigraphy

  • Uniformitarianism (Geological Principle):

    • The present geological processes operating today have shaped Earth’s surface in the past; the same natural laws apply across time.

    • Proponent: James Hutton; evidence from gradual processes like wind and rain leading to erosion and landform change.

  • Stratigraphy: study of strata (layers) and their relative positions to infer geological time and historical sequence.

  • Timeline context (geological time scale):

    • Holocene ~10,000 years ago

    • Pleistocene, Cenozoic, Mesozoic, Paleozoic, Proterozoic, Archean, etc., with approximate ages:

    • Archean ~3.6 × 10^9 to 2.5 × 10^9 years ago

    • Proterozoic ~2.5 × 10^9 to 541 × 10^6 years ago

    • Paleozoic (~541–252 Ma), Mesozoic (~252–66 Ma), Cenozoic (~66 Ma to present)

    • Specific epoch ages shown on the slide include: Paleocene (~65.5 Ma), Eocene (~56–34 Ma), Oligocene (~33.9 Ma), Miocene (~23–5 Ma), Pliocene, etc.; Jurassic (~199.6 Ma); Cretaceous (~145.5 Ma); Permian (~299 Ma); Triassic (~252.2 Ma); etc.

  • The stratigraphic timeline underpins the deep time framework used in evolutionary biology.

Catastrophism and Its Opposite

  • Catastrophism: extinct organisms in fossil strata may reflect past catastrophes rather than gradual change; associated with Georges Cuvier's interpretations.

  • Contrast with Uniformitarianism: gradual, ongoing processes over long timescales shape life and Earth.

Founders of Natural History and Taxonomy

  • John Ray (1627–1705): Father of Natural History; emphasized grouping by species and genus.

  • Carolus Linnaeus (1707–1778): Binomial nomenclature; introduced hierarchical taxonomy (Genus species, etc.); example: Homo sapiens.

  • Taxonomy and classification slide highlights organizing living things by relatedness (taxonomy example with common categories and binomial names).

Descent with Modification and Homology

  • Descent with Modification: organisms share common ancestry; over time, traits are inherited and modified.

  • Homology: shared ancestry reflected in similar structures across taxa (e.g., humerus, radius, ulna; carpals, metacarpals, phalanges) across HUMAN, CAT, WHALE, BAT illustrating common descent.

  • Homoplasy (convergent evolution): traits that appear similar due to independent evolution, not shared ancestry.

Lamarck’s Ideas and Orthogenesis

  • Jean-Baptiste Lamarck (1744–1829): proposed orthogenesis – a driving force toward greater complexity, suggesting evolution is directed and progressive.

  • Inheritance of acquired characteristics: traits altered through use/disuse could be passed to offspring.

  • Lamarck’s framework:

    • First Law: Use strengthens organs; disuse weakens and may lead to disappearance.

    • Second Law: Traits gained or lost due to environmental circumstances could be inherited if expressed in both sexes.

  • Simplified view: natural tendency toward increasing complexity via use/disuse; adaptive force transmitted to offspring.

Problems with Early Mechanisms and the Need for a Mechanism

  • Lamarckian framework faced a major question: what is the mechanism by which inheritance of acquired traits actually occurs across generations?

  • The missing mechanism identified: Natural Selection as a driving force for evolution.

Darwin and the Birth of Evolutionary Theory

  • Charles Darwin (1802–1882): sought to convince about reality of evolution and to provide a mechanism.

  • Major influences on Darwin:

    • Uniformitarianism

    • The Voyage of the HMS Beagle

    • Selective breeding (artificial selection)

    • Thomas Malthus's ideas on population growth and resource limits

  • The HMS Beagle voyage (1831–1836) provided critical observations supporting evolution, including biogeography and variation among related species.

Beagle Voyage and Illustrative Finches

  • Galápagos finches (Geospiza spp.) showed remarkable variation in beak size and shape among islands, often corresponding to available food resources.

    • Examples listed include Geospiza magnirostris, fortis, parvula; Certhidea olivacea; and other island-specific finches.

  • The Finch diversity provided a classic case supporting natural selection in response to ecological niches.

Selective Breeding and Artificial Selection

  • Observed in dogs and other domesticated species; demonstrates how selection can rapidly shift traits when humans act as the selecting agent.

  • The Terrier group, Hound, Sporting, Toy, Non-Sporting, Working, and Herding groups illustrate human-driven diversification of traits within a species.

Malthus and Population Theory in Evolutionary Context

  • Malthus argued that populations tend to grow geometrically while food resources grow arithmetically:

  • This mismatch between reproductive potential and resource availability creates competition and differential survival, laying groundwork for natural selection.

Alfred Russel Wallace and Darwin

  • Wallace (1823–1913) independently conceived natural selection; his ideas paralleled Darwin’s and contributed to the development of the theory.

Darwin’s Formal Definition of Natural Selection

  • Darwin’s definition (On the Origin of Species, 1859):

    • Owing to this struggle for life, variation, however slight and from whatever cause proceeding, if it be in any degree profitable to an individual of any species, in its infinitely complex relations to other organic beings and to external nature, will tend to the preservation of that individual, and will generally be inherited by its offspring. I have called this principle, by which each slight variation, if useful, is preserved, by the term Natural Selection.

  • Concise definition:

    • The process by which some organisms with traits that confer adaptation to the environment are more likely to survive and reproduce, thereby increasing the frequency of those advantageous traits in the population.

Evolution: Theory and Fact

  • Clarification often taught in courses:

    • Evolution by means of Natural Selection is a theory in the modern sense, but evolution itself is a demonstrable fact.

    • What evolution means in practice: changes in allele frequencies in populations over time.