chapter 4

Focus: Understand human origins through evolutionary concepts.
Dynamic and controversial field in anthropology, varying perspectives among public and scientists.
The Grand Gallery of Evolution at the National Museum of Natural History showcases specimens to educate about evolution.

Definition: Studies human evolution, biological variation, and cultures relative to the past.
Subfields:
- Human Biological Variation: Examines physical differences across populations.
- Paleoanthropology: Focus on fossils and artifacts of early humans.
- Primatology: Studies behavior and evolution of nonhuman primates.
- Bioarchaeology: Investigates human remains in archaeological contexts.
- Genetic Anthropology: Combines DNA analysis with historical data to track human migration and origins.
Historical context: Established around 1930, shifting focus from racial typology to evolution after Sherwood Washburn's influence.

Morphological Differences: Variations in height, jawline, and skin pigmentation across populations, linked to environmental adaptations.
Biochemical Differences: Genetic mutations affecting traits like smell and disease resistance (e.g., CCR5 gene and HIV).
Transition from physical anthropology to biological anthropology to evade racist associations.

Taxonomy: The classification and naming of organisms developed by Carolus Linnaeus.
Importance of taxonomy: Helps organize living organisms based on physical traits.
Binomial Nomenclature: A two-part naming system, e.g., Homo sapiens for humans.
Classification Hierarchy: Ranges from broad categories like kingdom and domain to specific ones like species.

Biological Species: Group of interbreeding organisms.
Ecological Species: Focus on natural selection that maintains species boundaries.
Phylogenetic and Mate Recognition Definitions: Based on genetic traits and mate recognition systems in specific species.

Key Terms:
- Alleles: Variants of a gene.
- Genotype: The genetic constitution of an organism.
- Phenotype: Observable traits resulting from genotype.
Cell Types: Prokaryotic (single-celled, without nucleus) vs. Eukaryotic (multicellular, with nucleus).
Mitosis vs. Meiosis: Differences in cell division for somatic vs. gametic cells.
Mendel’s Laws: Underpinning inheritance mechanisms, explaining dominant and recessive traits.

Evolutionary Theory: Change in allele frequency due to mutations and natural selection.
Historical Evolution Perspectives: Shifted from fixity of species (pre-19th century) to acceptance of change via scientists like Darwin and Lamarck.
Key Contributors: Cuvier (extinction), Lyell (geological processes), Wallace (independently developed ideas on natural selection).
Natural Selection: Mechanism by which species adapt to environments for survival.
Speciation Events: Allopatric (geographical isolation), sympatric (same location), and peripatric.

Features: Opposable thumbs, binocular vision, reduced reliance on smell, large brain size.
Primate Behavior: Studied through comparative analyses to understand cultural evolution in humans.
Behavioral Variation: Differences in tool use and hunting strategies based on environmental adaptations.

Deep Time: Geological eras and their significance to understanding primate evolution.
Fossil Formation: Conditions favoring fossilization and dating methods (relative vs. absolute).
Key Epochs: Paleocene, Eocene, Oligocene, and Miocene periods frame the evolution of primates.

Hominins: Species directly related to humans, characterized by bipedalism.
Archaeological Evidence: Fossils illustrating the transition to bipedal locomotion, such as those of Australopithecus afarensis.
Key Adaptations: Skeletal changes that facilitated upright walking and implications for human development.
Important Discoveries: Fossils like Ardipithecus ramidus and Australopithecus species illuminate hominin diversity and evolution.

Biological anthropology provides insights into human evolution, shaped by genetic, environmental, and behavioral factors. It utilizes the principles of taxonomy and the evidence of fossils to explore the evolutionary history. Key concepts include natural selection, speciation processes, and the classification of primates and hominins.