Molecularization of Race

Neo-Darwinism

Combines Darwin’s natural selection with Mendel’s heredity ideas; undermines biological race concept and recognizes all humans as a single species.

Clines

A pattern of gradually shifting frequency in phenotypic traits from population to population, not clustering as biological race concepts assumed.

Molecularization of race

Revisions that connect race and biology, examining genotypic variation.

Species

A distinct segment of evolutionary lineage.

Phylogenetic species concept

Identifies species based on unique features that distinguish them from related species.

Reticulation

Occurs when separated populations merge and reproduce later, linking anatomically modern humans and Neandertals.

Gene pool

All genes in the bodies of all members of a given species.

Gene frequency

How often variants of a specific gene occur within a population.

Population genetics

Measures stability or change in gene frequencies of populations over short periods.

Polymorphous

Alleles that come in a range of different forms, accounting for most genetic variation across populations.

Private polymorphism

Alleles found in some but not all members of a population, e.g., diego antigen.

Human variation

Older concepts of race emphasized phenotypic variation, with no deep biological differences between racial groups.

Cline maps

Examine single traits across the human species, revealing trait distributions that do not neatly divide into subpopulations.

Natural selection

An evolutionary process that can alter gene frequencies.

Gene flow

Movement of genes from one population to another, e.g., European colonizers breeding with indigenous people.

Genetic drift

Random changes in gene frequencies due to sudden population size reduction.

Bottleneck effect

Genetic drift occurring when populations are suddenly reduced in size by disaster or disease.

Founder effect

Occurs when small subgroups establish themselves apart from larger populations.

Inbreeding

Increases the proportion of homozygous combinations of alleles and reduces genetic variation.

Microevolution

Small-scale evolutionary changes within populations.

Balanced polymorphism

A situation where heterozygous genotypes are fitter than either homozygous genotype.

Gene Interaction

Explains how discrete genes influence phenotypic traits through pleiotropy and polygenic effects.

Major effect gene

A gene at one locus whose expression critically affects the phenotype.

Phenotypic plasticity

Physiological flexibility allowing organisms to respond to environmental stressors.

Acclimatization

Changes in body function in response to physical stress, e.g., shivering.

Epigenetic marks

Chemical modifications in DNA that affect gene expression and are essential for normal development.

Skin Color

Adaptive trait related to ultraviolet radiation exposure, evolving independently in similar environments.

Intelligence

Multiple types of intelligence exist, and IQ tests do not demonstrate racial differences.

Human Genome Project

Aimed to identify all genes in human DNA and address legal and social issues.

Biocultural approaches

Reveal how social differences can shape biology, affecting the nervous system.

Formal models

Mathematical formulas predicting outcomes of human interactions under different conditions.

Predicting Human Evolution

Explains survival at any cost as "natural," emphasizing cultural adaptations based on learning.