ANTH:1301 Human Origins Midterm Exam 1 Vocabulary

Comprehensive key term flashcards for Human Origins Midterm 1 covering key concepts, historical figures, cellular genetics, evolutionary forces, and macroevolution.

Biological anthropology

The study of human biology within the framework of evolutionary biology and biocultural evolution.

Primatology

The study of non-human primates as hominin models and the preservation of endangered species.

Paleopathology

Prehistoric forensics investigating diseases, trauma/aggression, nutritional status, and growth disorders.

Genetics

The study of heredity analyzed at three levels of understanding: biochemical, chromosomal, and populational.

Inductive reasoning

Moving from the specific to the general; a methodology where a generalization is developed from specific data.

Deductive reasoning

Moving from the general to the specific; a powerful methodology where predictions are developed from generalizations.

Parsimony

Also known as Occam’s Razor; the principle that in explaining something, no more assumptions should be made than are necessary.

Hypothesis

A testable explanation for a set of data based on limited evidence that serves as a starting point for further investigation.

Generalizing Hypotheses

Descriptions of observed patterns in nature.

Explanatory Hypotheses

Hypotheses that explain why observed patterns in nature are generated and maintained.

Null hypothesis

A hypothesis developed in contrast to the original hypothesis that assumes no relationship between variables and is subject to disproof.

Scientific investigation

An effort to account for observable phenomena with testable models where disproof, skepticism, and repeated testing prevail over advocacy.

Organic evolution

Change in the properties of populations of organisms through genetic transmission across generations; specifically, a change in allele frequency from one generation to another.

Great Chain of Being

A Middle Ages hierarchical worldview asserting a static organic world with fixity of life forms since creation.

Fossils

Fossilized remains of hard or soft tissue whose discovery suggested species transformed or evolved over time.

Individual variation

The observation that no two organisms are exactly alike, where variation within groups leads to variation between groups.

Darwinian fitness

The possession of favorable traits beneficial to survival and differential reproductive success.

Copernicus

Nicolas Copernicus (1473–1543), a mathematician/astronomer who replaced the Ptolemaic view with a heliocentric universe model.

Linnaeus

Carolus Linnaeus (1707–1778), a Swedish naturalist who authored Systema Naturae, created binomial nomenclature, and grouped humans with animals under a static classification.

Binomial nomenclature

The taxonomic standard of two-part naming for species (e.g., Homo sapiens) established by Carolus Linnaeus.

Lamarck

Jean-Baptiste Lamarck (1744–1829), the first to provide a testable model for evolutionary change through the inheritance of acquired characteristics.

Inheritance of Acquired Characteristics

The proposed evolutionary mechanism that organisms can alter their bodies in beneficial ways during their lifetime and pass those acquired traits to offspring.

Cuvier

Georges Cuvier (1769–1832), a French paleontologist/anatomist who introduced the concept of extinction and developed catastrophism.

Catastrophism

The view explaining extinction as the result of periodic violent turnover events in Earth's geological and natural history.

Lyell

Charles Lyell (1797–1875), geologist and author of Principles of Geology who popularized deep time and geological uniformitarianism.

Geological Uniformitarianism

The model stating that past geological events (erosion, vulcanism, glacial movement) are identical to ongoing processes that produce the current geological landscape.

Malthus

Thomas Malthus (1766–1834), author of Essay on the Principle of Population, who posited that geometric human population growth is checked by arithmetic food production growth.

Darwin

Charles Darwin (1809–1882), author of Origin of Species (1859) who identified natural selection as a key evolutionary force driven by variation.

Natural selection

Genetic changes in a population resulting from differential reproductive success between individuals interacting with their environment.

Nucleotide

The basic building block unit of DNA, composed of a phosphate group, a deoxyribose sugar, and one of four nitrogenous bases.

4 DNA bases

The nitrogenous bases adenine, guanine, cytosine, and thymine, whose specific sequence encodes genetic information in DNA.

Gene

A sequence of chemical bases specifying a chain of amino acids to form protein molecules; a functional subunit of a chromosome.

Allele

An alternate form of a gene located at the same locus on paired chromosomes that governs the same trait.

Triplet

A three-base sequence in DNA coding for specific amino acid chains, producing up to $4^3 = 64$ potential combinations.

Codon

A three-base sequence in mRNA complementary to a DNA triplet that specifies a particular amino acid during translation.

Exon

A protein-coding segment of DNA that is transcribed into RNA and translated into a polypeptide chain.

Intron

A non-coding segment of DNA that is copied into RNA during transcription but removed or excised prior to translation.

Mutation

A heritable change in DNA that serves as the ultimate source of all new genetic variation.

Chromosome

A structural unit of the genome composed of DNA coiled around specialized proteins inside the nucleus.

Centromere

The region of a chromosome where two sister chromatids are joined together.

Karyotype

The specific array, number, size, and shape configuration of chromosomes characteristic of an organism or species.

Homologous chromosomes

A matched pair of chromosomes carrying genes governing the same traits, with one inherited from each parent.

Somatic cell

Any body cell of an organism (excluding sex cells) that undergoes mitosis to produce identical diploid daughter cells.

Gamete

A haploid sex cell (such as a sperm or egg) produced through meiosis that is necessary for sexual reproduction.

Diploid

Cells containing a full double set of paired chromosomes ($46$ chromosomes arranged in $23$ pairs in humans).

Haploid

Cells containing half the full set of chromosomes ($23$ chromosomes in humans), typical of mature gametes.

Mitosis

The process of cell division in somatic cells that results in two genetically identical diploid daughter cells.

Meiosis

The cell division process in sex cells involving replication and two divisions, resulting in four genetically distinct haploid gametes.

Crossing over

The exchange of genetic material between non-sister chromatids of homologous chromosomes during early meiosis that reshuffles existing variation.

Blending inheritance

An obsolete pre-Mendelian concept proposing that parental traits mix together continuously to yield intermediate offspring traits.

Principle of Segregation

Mendel's First Law, which states that discrete units (alleles) governing traits occur in pairs and separate independently during meiosis.

Principle of Independent Assortment

Mendel's Second Law, which states that alleles controlling two or more different traits segregate independently of one another during gamete formation.

Genotype

The underlying internal genetic makeup or specific combination of alleles possessed by an individual at a locus.

Phenotype

The observable physical or functional external manifestation of an organism's genotype.

Homozygous

Possessing two identical alleles at a specific locus on homologous chromosomes.

Heterozygous

Possessing two different alleles at a specific locus on homologous chromosomes.

Autosomal Dominant

A pattern of inheritance where a single copy of an allele causes expression of the corresponding phenotypic trait.

Autosomal Recessive

A pattern of inheritance where two copies of a recessive allele are required for expression of the phenotypic trait.

Linkage

The tendency for alleles located close together on the same chromosome to be inherited together more frequently than predicted by independent assortment.

Pleiotropy

The genetic condition wherein a single gene exerts multiple phenotypic effects across seemingly unrelated traits.

Polygenic inheritance

A situation where a single phenotypic trait is controlled by the additive effects of alleles at multiple distinct genetic loci.

Modern Synthesis

The theoretical framework developed between 1936 and 1947 reconciling Mendelian genetics with Darwinian natural selection.

Population

A localized group of individuals of the same species sharing a defined geographical space within which interbreeding occurs.

Gene Pool

The total aggregate of all alleles and genetic information present within an interbreeding population.

Genetic Drift

Random, non-directional fluctuations in population allele frequencies caused by chance sampling events.

Gene Flow

The movement and exchange of alleles between distinct populations through migration, rendering their gene pools more homogeneous.

Directional Selection

A mode of natural selection favoring phenotypic variants at one extreme, shifting allele frequencies in a single direction.

Disruptive Selection

A mode of natural selection favoring extreme phenotypic values over intermediate values, producing a bimodal distribution.

Stabilizing Selection

A mode of natural selection favoring average or intermediate phenotypes over extreme variations, maintaining population norm.

Taxonomy

The system and practice of naming and classifying real organisms into formal categories.

Phylogeny

The study and evolutionary history of relationships and line of descent among organismal groups.

Cladogram

A branching diagram representing testable hypotheses of evolutionary relationships based exclusively on shared derived traits.

Homologous structures

Anatomical features shared by different organisms due to inheritance from a common ancestor.

Biological Species Concept

Ernst Mayr's definition of a species as a group of interbreeding natural populations that are reproductively isolated from other such groups.

Speciation

The primary macroevolutionary process through which new species arise when gene flow is interrupted and populations become reproductively isolated.

Macroevolution

Large-scale evolutionary changes occurring above the species level over vast geological time periods.

Adaptive Radiation

The rapid diversification of an ancestral lineage into multiple new species adapted to distinct ecological niches.

Phyletic Gradualism

The evolutionary model proposing that species transform continuously and slowly through accumulated slight changes over time.

Punctuated Equilibrium

The evolutionary model proposing long periods of stasis interrupted by brief, rapid bursts of speciation and macromutation.

Paleoanthropology

An interdisciplinary subfield of physical anthropology focused on studying the fossil evidence for human evolution and extinct hominins.

Translation

The step in protein synthesis occurring at the ribosome where mRNA codons are decoded into amino acid chains.