Biological Anthropology and Evolutionary Thought

Vocabulary flashcards covering fundamental concepts in biological anthropology, history of evolutionary thought, natural selection, Mendelian genetics, cell division, forces of evolution, and speciation mechanisms based on lecture notes.

Biological anthropology

The study of human beings as biological organisms using an evolutionary approach.

Paleoanthropology

The study of the fossil record of ancestral humans and primates, focusing on skeletal remains and bones.

Archaeology

The study of the material culture of past human populations, including tools, art, pottery, and artifacts.

Forensic anthropology

The study of human skeletal remains applied within a legal context to identify individuals and determine the cause of death.

Science

The process of gaining information about natural phenomena through empirical observation and experimentation.

Anaximander

A $6\text{th}$-century BCE Greek thinker who sought natural origins for earthly phenomena and proposed that humans and other animals descended from fish.

Eidos

Plato's concept of an abstract, perfect form that is imperfectly imitated in the real world, holding that species possess a fixed and unchangeable essence.

Scala Naturae

Aristotle's hierarchical classification scheme (The Great Chain of Being) that organized natural organisms and placed humans at the top of nature.

Al Jahiz

A Middle Eastern scholar who noted that animals engage in a struggle for existence and resources to survive and breed, and that the environment influences organism characteristics.

Nasir Al Din

A Persian architect and mathematician who recognized continuities between humans and other animals and noted that organisms adapt to their environment.

Li Shizhen

A Chinese naturalist ($1518\text{--}1593$) who recognized environmental influence on organisms and utilized a binomial system and hierarchical classification scheme.

Galileo Galilei

A Renaissance scientist ($1564\text{--}1642$) who established an empirical approach to testing natural phenomena and confirmed Copernicus's idea that Earth is not the center of the celestial system.

John Ray

A naturalist ($1672\text{--}1705$) who defined a species as a group of organisms capable of reproducing with one another and introduced the genus classification.

Carolus Linnaeus

A scientist ($1707\text{--}1778$) who created the binomial system of nomenclature and a hierarchical classification system grouping organisms based on similarities.

Comte de Buffon

The author of Histoire Naturelle ($1749$) who suggested that the external environment is an important agent for biological change and observed that variation reflects environmental influences.

Taxonomy

The practice of biological classification, derived from the Greek words Taxis (order or arrangement) and Nomos (law or science).

Phylogeny

A hypothesis of evolutionary relationships among groups of organisms.

Theory of inheritance of acquired characteristics

Jean Lamarck's $1809$ evolutionary mechanism proposing that dynamic interactions with the environment cause individual organisms to acquire traits during their lifetime that are passed to offspring.

Catastrophism

Georges Cuvier's theory that sudden, violent environmental events (such as floods or volcanic eruptions) cause mass extinctions, explaining changes in the fossil record across rock layers.

Uniformitarianism

Charles Lyell's geological principle stating that ongoing natural processes occurring slowly and gradually today persisted in deep time in the past.

Thomas Malthus

The author of the Principle of Population, who argued that human populations increase exponentially faster than food production, leading to a struggle for existence.

Alfred Russel Wallace

A naturalist who independently arrived at the tenets of natural selection based on field observations in South America and Southeast Asia.

On the Origin of Species by Means of Natural Selection

Charles Darwin's $1859$ book establishing biological evolution, common descent with modification, gradualism, and natural selection as the driving mechanism of evolution.

Thomas Huxley

The author of Man's Place in Nature ($1863$), who applied evolutionary theory to humans by describing close anatomical similarities between African apes and humans.

Descent of Man

Charles Darwin's $1871$ publication predicting that humans and African apes share a close evolutionary relationship and originated in Africa.

Blending theory of inheritance

The pre-Mendelian hypothesis that parental traits are permanently averaged out and blended together in offspring.

Particulate inheritance

Gregor Mendel's model demonstrating that traits are inherited as discrete unit factors (genes) that remain distinct across generations rather than blending.

Pure breeding line

A population of organisms that breeds true for a particular physical trait across generations.

Genotype

The complete set of genetic factors ($2$ gene copies, one inherited from each parent) that interact to determine an organism's phenotype.

Phenotype

The observable physical or physiological expression of a trait.

Homozygous

Possessing two identical copies of a genetic factor or allele controlling a specific trait.

Heterozygous

Possessing two different genetic factors or alleles controlling a specific trait.

Law of Segregation

Mendel's law stating that paired unit factors separate randomly during sex cell formation so that each sperm or egg cell receives one factor with equal likelihood.

Law of Independent Assortment

Mendel's law stating that the distribution of one pair of hereditary factors into gametes does not influence the distribution of other factor pairs.

Nucleus

The cellular organelle that contains genetic information and DNA inside eukaryotic cells.

Mitochondria

Cellular organelles responsible for energy production that possess their own distinct DNA.

Ribosomes

Cellular organelles formed mostly of RNA that function in protein synthesis.

Chromosome

A tightly compact organizational structure of DNA wrapped around histones inside the cell nucleus.

Gene

A segment of genetic material that encodes for the expression of a particular trait.

Locus

The specific physical location of a gene on a chromosome.

Allele

An alternate version of a gene located at a specific locus.

Autosomes

Chromosomes numbered $1$ through $22$ in humans that govern physical traits and exist in homologous pairs.

Sex chromosomes

The $23\text{rd}$ pair of chromosomes ($\text{XX}$ in females, $\text{XY}$ in males) responsible for sex determination in mammals.

Somatic cells

Diploid body tissue cells containing $46$ chromosomes ($2N$) that replicate through mitosis to repair and replace tissue.

Gametes

Haploid sex cells (ova and sperm) containing $23$ chromosomes ($N$) produced through meiosis to pass genetic information across generations.

Zygote

The diploid cell formed by the union of a haploid sperm and a haploid egg cell.

Mitosis

The process of somatic cell division resulting in $2$ genetically identical diploid daughter cells.

Meiosis

The process of sex cell division resulting in $4$ genetically unique haploid gametes, each containing $23$ chromosomes.

Crossing over

The exchange of genetic material between adjacent non-sister chromatids of homologous chromosomes during prophase I of meiosis.

Random assortment

The reshuffling of maternal and paternal genetic material caused by the random arrangement of chromosome pairs along the cell equator during meiosis I.

Nondisjunction

The failure of homologous chromosome strands or chromatids to separate properly during meiosis, resulting in abnormal chromosome numbers.

Population

A group of organisms of the same species potentially capable of successful reproduction within a given area.

Gene pool

The sum total of all alleles carried by all individuals within a population.

Evolution

A change in allele frequencies within a population from one generation to the next.

Genetic drift

Random changes in population allele frequencies from one generation to the next due to chance events rather than natural selection.

Founder effect

A component of genetic drift occurring when a small subgroup isolates or migrates, establishing a new population with allele frequencies distinct from the original population.

Population bottleneck

A drastic reduction in population size for at least one generation, reducing gene variants and adaptability.

Gene flow

The introduction and transfer of new alleles between populations resulting from interbreeding.

Inbreeding

Mating between biologically related individuals, which increases homozygosity across genetic loci.

Sexual selection

Differential reproductive success among individuals of the same sex resulting from competition for mates.

Sexual dimorphism

Systematic phenotypic differences (such as size or coloration) between males and females of the same species.

Directional selection

A mode of natural selection where an extreme phenotype is favored, causing allele frequencies to shift over time.

Stabilizing selection

A mode of natural selection in which genetic diversity decreases and the population mean stabilizes on a intermediate trait by selecting against extreme phenotypes.

Adaptation

A trait produced by natural selection that increases an organism's fitness in its specific environment.

Red Queen Hypothesis

The evolutionary concept stating that species must continually adapt and evolve simply to maintain survival amidst competing, coevolving organisms.

Microevolution

Small-scale evolutionary changes in allele frequencies within a species or population over a short time period.

Macroevolution

Large-scale evolutionary changes occurring over long time periods, resulting in the appearance of new species or higher taxonomic categories.

Biological Species Concept

The definition of a species as groups of interbreeding natural populations that are reproductively isolated from other groups.

Recognition Species Concept

The definition of a species emphasizing unique phenotypic traits or behaviors that enable individual members to recognize each other for mating.

Cladogenesis

A pattern of speciation where a parent lineage splits into two or more distinct descendant lineages.

Anagenesis

A pattern of speciation where a single species slowly accumulates changes over time until it evolves into a new distinct species.

Allopatric speciation

Speciation occurring via complete geographic isolation between populations.

Parapatric speciation

Speciation occurring between adjacent populations involving only partial geographic isolation and limited gene flow.

Sympatric speciation

Speciation occurring within the same geographical area in the complete absence of geographic isolation.

Ecological niche

The specific role a species plays in its environment, including its interactions with other species, community utilization, and habitat resource use.

Adaptive radiation

The rapid evolutionary diversification of a single ancestral species into multiple descendant species that fill diverse ecological niches.

Punctuated equilibrium

A macroevolutionary model proposing that evolutionary change proceeds through long periods of stasis punctuated by brief periods of rapid change.

Gradualism

A macroevolutionary model proposing that evolutionary change proceeds gradually through the accumulation of small-scale changes over time.

Analogy

Structures that are similar in appearance or function across organisms but evolved independently due to similar selection pressures rather than shared ancestry.

Homology

Similarities shared between organisms because they were inherited from a common ancestor.

Ancestral homology

A shared homologous trait inherited from a remote or distant common ancestor, present across a broad group of species.

Derived homology

A specific homologous feature unique to a specific taxon, acquired by its most recent common ancestor and shared exclusively by its members.