CARTA Glossary

Displaying 201 - 300 of 650 defined words
Word Definition Related Vocabulary
Epidemic

The rapid spread of a disease to a significant percent of a given population.

Epidemiology

The branch of medicine that studies and analyzes the incidence, distribution, patterns, determinants, and possible control of diseases and other health factors.

Epigenetic

Biological information not encoded directly in DNA.

Epigenetics

A term first coined by the developmental biologist, Conrad Waddington, in 1942 to explain how a singular genotype might produce variations in phenotype across development. He argued that some level of regulation must exists “above” or “over” genes to determine when and where they are expressed. Today the term refers to stable alterations in gene expression without changes to the underlying DNA sequence.

Epigenome

Molecular modifications of the DNA and its associated histone proteins, affecting its function.

Etomidate

An intravenous agent used for general anesthesia and sedation for short procedures that suppresses corticosteroid synthesis.

Euchromatin

Open chromatin, allowing information to be read.

Eukaryotes

Organisms whose cells have a nucleus enclosed within membranes. (see Prokaryotes)

Eumelanin

The most common type of melanin found in human skin and hair. There are two types, brown eumelanin and black eumelanin, which are involved in pigmentation. Deficiency causes albinism.

Evolutionary Medicine

The application of modern evolutionary theory to understanding health and disease.

Excitatory neurotransmitter

A chemical messenger that increases the likelihood that the neuron will fire an electrical signal (depolarization of the membrane) called an action potential.

Exons

Sequences at a locus that encode proteins

Extended amygdala

A paired macrostructure in the brain that is involved in reward cognition.

Falciparum Malaria

Human-specific (malignant) malaria caused by the protozoan parasite, Plasmodium falciparum.

Falémé Valley

Eastern Senegal. Excavations have led to the the discovery of paleolithic occupations from different periods, cultures, and lithic technologies.  

False Beliefs

The ability to recognize that others can have beliefs about the world that are diverging. An important component of Theory of Mind.

Fatty Acid

A molecule composed of a long chain of lipid-carboxylic acid, which is either saturated (single bonds between the components of the fatty acid chain) or unsaturated (at least one double bond within the fatty acid chain).

Fitness (Darwinian)

The relative likelihood that an allele will be represented in future generations (relative to other alleles in the same population). Compare with Reproductive Success.

Fixed Alleles

Replaced all other alleles in a population.

Fomite

Inanimate objects (clothes, furniture, door handles, etc.) that when contaminated can transfer disease.

Foraging

Searching for wild food or provisions as opposed to cultivating food crops or breeding livestock.

Fos

A protein that is rapidly synthesized in neurons when they become active and therefore is used as a marker of neuron activity and is involved in regulating gene expression.

FOXP2 A gene in humans that encodes for a transcription factor protein and is involved in the production of speech.
Fragmented Maternal Care

A measure of abnormal mothering in rodents. Fragmentation score reflects disruptions in the temporal pattern of care typically displayed by rodents. High fragmentation scores indicate shorter nursing bouts and generally erratic behavior.

Frontal Lobe (Brain)

The largest of the four major lobes of the brain in mammals, and is located at the front of each hemisphere. It is devoted to action such as skeletal movement, ocular movement, speech control, the expression of emotions. In humans, the largest part of the frontal cortex is the prefrontal cortex.

Frontoparietal Networks

Human frontal and parietal lobes form a network that is crucially involved in the selection of sensory contents by attention.

Functional DNA

Encodes biological information.
~2% of all DNA: Codes for proteins.
~80% of all DNA: Regulates gene activity.

Functional Magnetic Resonance Imaging (fMRI)

A neuroimaging technique for measuring and mapping brain activity that is noninvasive and safe. The phenomenon of nuclear magnetic resonance (NMR) is used to generate a signal that can be mapped and turned into an image of brain activity.

Funeral

Intentional, ritualistic disposal of the deceased. May include behaviors such as placement of grave goods (artefacts and/or natural materials such as flowers) and positioning of interred body(ies).

GABA receptors

A class of membrane proteins that act as receptors for the neurotransmitter GABA and are mostly found on inhibitory neurons.

Galago

A number of species of prosimians that are small, nocturnal, and native to continental Africa. Also known as bushbabies. Galagos often nest in tree hollows during the day. Chimpanzees have been observed hunting with “spears” for nested galagos, and they are also hunted by Hadza hunter-gatherers.

Gardnerella

A genus of Gram-variable-staining facultative anaerobic bacteria of which Gardnerella vaginalis is the only species.

Gardnerella vaginalis

A facultatively anaerobic Gram-variable rod that is involved, together with many other bacteria, in bacterial vaginosis in some women as a result of a disruption in the normal vaginal microflora.

Gastroenteritis

Inflammation of the stomach and small intestine typically caused by a virus, but can also be caused by bacteria, parasites, and fungi. Symptoms may include diarrhea, vomiting, and abdominal pain.

Gene

DNA sequence which encodes a specific function.

Gene Expression

The process by which the information contained within a gene (nucleotide sequence) is used to direct protein synthesis and dictate cell function. Nearly all of the cells in the body contain identical genes, but only a subset of this information is used or expressed at any time. The genes expressed in a cell determine what that cell can do.

Gene Flow

Movement of alleles between populations as is achieved by mating.

Gene Regulation

Alterations of gene expression/activity.

Gene-Culture Co-Evolution Theory

A branch of theoretical population genetics that models the transmission of genes and cultural traits from one generation to the next, exploring how they interact. Also known as “biocultural evolution” or “biological enculturation” (feedback between culture and biology).

General anesthesia

A combination of medications that put you in a sleep-like state before medical procedures.

Genetic Adaptation

A biological characteristic with a heritable basis that improves reproduction and/or survival and results from evolution by natural selection.

Genetic Drift

Change in allele frequencies, including fixation and loss, by chance.

Genetics

The study of genes and their inheritance.

Genius

A person who is exceptionally intelligent or creative, either generally or in some particular respect.

Genome

All DNA in a cell. Also refers to the DNA sequence that typifies an individual or species.

Genome Wide Association Study (GWAS)

An approach for “gene mapping” in which hundreds of thousands of SNPs are tested statistically for genetic associations with a phenotype.

Genomic Imprinting

Modification of the genome at the level of DNA (e.g. methylation) or its packaging into chromatin (histone tail modification via phosphorylation, acetylation, ubiquitination or glycosylation).

Genomics

The study of genome structure/function.

Genotype

The two alleles at one or more diploid loci.

Genotyping

Characterizing genetic variants at one or more loci.

Genus

A taxonomic rank used in biological classification of living and fossil organisms to group closely related species. In binomial nomenclature, the genus name plus species name forms the binomial species name (e.g. Homo sapiens).

Germinal Zone A region where cell division and proliferation occurs during vertebrate central nervous system development consisting of 2 layers lining the ventricles (ventricular zone and subventricular zone).
Glia (aka Neuroglia)

Non-neuronal cells in the central nervous system and the peripheral nervous system that do not produce electrical impulses. Their function is to ensure homeostasis, form myelin, and provide support and protection for neurons.

Global Neuronal Workspace (GNW)

A hypothesis that offers a simple connectomic scheme based upon the contribution of neurons with long-range axons to conscious processing. Their reciprocal interactions contribute to the formation of a global workspace, broadcasting signals from the sensory periphery to the whole brain, thus yielding “conscious” experience. The GNW hypothesis privileges cortical pyramidal cells with long-range excitatory axons, particularly dense in prefrontal, temporoparietal, and cingulate regions, that, together with the relevant thalamocortical loops, reciprocally interconnect multiple specialized, automatic, and non-conscious processors. Another important feature of this hypothesis is that the GNW activates in a non-linear manner, called ‘‘ignition,’’ upon access to conscious processing. Ignition is characterized by the sudden, coherent, and exclusive activation of a subset of workspace neurons coding for the current conscious content, with the remainder of the workspace neurons being inhibited.

Glucocorticoids

A class of corticosteroids that are involved in stress response and are also a part of the feedback mechanism in the immune system. E.g., Dexamethasone (a synthetic glucorticoid).

Glycans

One of the four classes of major biomolecules. Glycans consist of varying numbers of sugars (monosaccharides) attached to proteins or lipids or secreted as free glycans. Glycans are essential biomolecules whose functions can be divided into three broad categories: structural and modulatory properties (including nutrient storage and sequestration), specific recognition by other molecules, and molecular mimicry of host glycans.

Glycolipids

A type of a lipid (fat) with an attached glycan that functions to maintain the stability of the cell membrane and to facilitate cellular recognition. Glycolipids are crucial in immune response and tissue formation.

Glycoprotein

A class of proteins with covalently attached glycans. Glycoproteins play a part in important cellular functions like embryonic development, cell-to-cell recognition, cell adhesion, and immune functions.

Gram-Negative and Gram-Positive Staining

A characterization of bacteria based on how they differentially react with a chemical stain (crystal violet) based on their cell wall constituents.

Grandmother Hypothesis

An explanation of the post- menopausal life stage of human females whereby the existence of grandmothers serves as a biological and social adaptive advantage for humans. Post-reproductive life stages are non-existent among non-human primates, so it is hypothesized that humans evolved to have grandmothers and grandmothering to have individuals who are free to invest their energy into the offspring of their children. This off-loads the reproductive cost of parenting through social kin-networking, and off-set the resource cost of brain- building as parents are freed to provision resources. Increased resource procurement may reduce the inter-birth interval by allowing for earlier weening, which in turn increases offspring production potential, passes down generational knowledge, and increase social networks. In doing so, the grandmother ensures the survival of her genes in subsequent generations. The extended post-reproduction lifestage of grandmothers likely had the added output of producing grandfathers, who also provide benefits to the extended family, as well as their own extended reproductive timeline that competes with subsequent generations.

Gray Matter (Brain)

A major component of the central nervous system that includes regions of the brain involved in muscle control, sensory perception such as seeing and hearing, memory, emotions, speech, decision making, and self-control. Gray matter development peaks the third decade in humans.

Great Apes

A taxonomic family denoting the extant chimpanzees, bonobos, gorillas and orangutans.

Guillain–Barré Syndrome (GBS)

A rapid-onset muscle weakness caused by an autoimmune response in which the body’s immune system mistakenly attacks and damages the peripheral nervous system. Initial symptoms typically begin in the feet and hands with changes in sensation, pain, and muscle weakness, which then spreads to the arms and upper body of both sides. Sometimes this immune dysfunction is triggered by an infection or, less commonly by surgery, and rarely by vaccination.

Gyrification

The process of forming the characteristic folds of the cerebral cortex.  The peak of such a fold is called a gyrus (plural: gyri), and its trough is called a sulcus (plural: sulci).

Gyrus (Brain)

A ridge on the cerebral cortex that, along with surrounding sulci (furrows) creates the folded appearance of the brain in humans and other mammals.

Hadza (Hadzabe)

An indigenous ethnic group of traditionally nomadic hunter-gatherers from the central Rift Valley and Serengeti Plateau of Tanzania. Tourism, encroachment by pastoralists, and land rights disputes critically threaten their way of life.

Handaxe

A prehistoric stone tool with two faces and is usually made from flint, basalt, sandstone, quartzite, or chert.

Haplogroup

A set of similar haplotypes that share a common ancestor.

Haploid

One set of unpaired chromosomes.

Haplotype

A set of alleles along neighboring positions on a chromosome that are inherited together.

Health Disparity

Differences in the burden of disease, injury, violence, and health care as experienced by socially disadvantaged populations.

Hemideletion

One of two paired chromosomes is affected by a deletion. The other chromosome is intact. 

Hemoglobin

A protein complex within red blood cells (RBCs) that binds to oxygen molecules in the lungs for delivery to tissues throughout the body. The same complex also binds carbon dioxide (CO2) and carries it back to the lungs.

Hemoglobin S

The abnormal hemoglobin protein in red blood cells (RBCs) that causes RBCs to assume a sickle, or crescent shape.

Hemoglobin Subunit Beta Gene (HBB)

A gene that provides instructions for making beta-globin, a protein component of hemoglobin. Sickle Cell Anemia is a disorder caused by a mutation in the HBB gene.

Herd Immunity

Sometimes also called “herd protection” or “indirect immunity,” this is when most of a population is immune to a specific contagious disease, which slows its spread to others that are not immune. However, because the level needed to reach this kind of immunity is so high (about 80-90% of the population), it invariably means that a lot of individuals must be infected (and often can die) before herd immunity can be achieved.

Heritability

A statistic used in the fields of breeding and genetics that estimates the degree of variation in a phenotypic trait in a population that is due to genetic variation between individuals in that population.

Heterochromatin

Tightly wrapped and inactive chromatin.

Heterozygotes

Have two different alleles at a locus.

Hippocampus (Brain)

A part of the limbic system that plays important roles in the consolidation of information from short-term memory to long-term memory, and in spatial memory that enables navigation. A major component of the brain of humans and other vertebrates. Humans and other mammals have two hippocampi, one in each side of the brain. It is named after its resemblance to the shape of a sea horse.

Histone Deacetylase Inhibitor (HDACi)

A drug that inhibits histone deacetylases or molecules involved in modifying histone proteins. Histone deacetylases typically function to reduce chromatin accessibility and gene expression. Therefore, administration of this drug allows for higher levels of gene expression.

Histone Modification

A covalent post-translational modification (PTM) to histone proteins which includes methylation, phosphorylation, acetylation, ubiquitylation, and sumoylation. The PTMs made to histones can impact gene expression by altering chromatin structure or recruiting histone modifiers. 

Histones

Chief protein components of chromatin and can be chemically modified as part of epigenetics.

Holocene

The current geological epoch, from about 11.7 kya to the present.

Homeostasis

A relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes.

Hominid

A classification comprising all living and extinct “Great Apes” and humans.

Hominin

A classification of species comprising humans and our extinct relatives following the split with the common ancestor with chimpanzees.

Homo

The genus that comprises the species Homo sapiens, as well as several extinct species classified as ancestral to, or closely related to, humans.

Homo erectus

An extinct hominin species with fossil evidence from at least 1.9 million years to 70 thousand years ago and found from Africa to Indonesia. May have been the first hominin to leave Africa. H. erectus DNA may be retrievable from other species due to archaic admixture.

Homo habilis

An extinct archaic species of the genus Homo dating to ~2.1 to 1.5 mya. H. habilis means “handy man” and was named so because of its association with stone tools.  H. habilis has intermediate morphology between Australopithecus and Homo erectus. There is ongoing debate if H. habilis should be moved to the Australopithecus genus.  Initial discovery was made by Mary and Louis Leakey at Olduvai Gorge in Tanzania between 1962 and 1964.

Homo naledi

An extinct hominin species whose fossil evidence dates to 335-236 kya. An assemblage of 15 H. naledi skeletons were first found in the Dinaledi Chamber of the Rising Star cave system in 2013 (since then, a second chamber has been found with H. naledi skeletons). The fossils possess a mix of “archaic” traits similar to genus Australopithecus (e.g. cranial and pelvic morphology) and “modern” traits characteristic of genus Homo (e.g. hand morphology). H. naledi lived contemporaneously with anatomically modern humans, Neanderthals, and Denisovans but is not likely a direct ancestors of humans living today.

Homo sapiens

The hominin species comprising all living humans. Meaning “wise man” in Latin, the name was introduced by Carl Linnaeus in 1758. The earliest fossil evidence of Homo sapiens appears in Africa around 300 kya (see Jebel Irhoud Hominins).

Homology

Similarity in DNA or phenotype because of shared evolutionary history from a common ancestor.

Homoplasy

Similarity in DNA sequence or phenotype that has evolved independently.

Homozygotes

Have two identical alleles at a locus

Host

A living organism on or in which a parasite, pathogen, commensal or symbiont lives (see Parasitism).

Howiesons Poort

A lithic technology cultural period in the Middle Stone Age in Africa named after the Howieson’s Poort Shelter archeological site near Grahamstown, South Africa. Dates range from ~65.8 kya to 59.5 kya. Examples include composite weapons hafted with ochre and gum compound glue and microlith blades, bone arrows, and needles.

Human Accelerated Regions (HARs)

A set of 49 segments of the human genome that are conserved throughout vertebrate evolution but are strikingly different in humans. They are named according to their degree of difference between humans and chimpanzees. Some of these highly mutated areas may contribute to human-specific traits while others may represent “loss of function” mutations, possibly due to the action of biased gene conversion rather than adaptive evolution.

Hunter-Gatherer

A human living in a society in which most or all food is obtained by foraging (collecting wild plants and pursuing wild animals), in contrast to agricultural societies, which rely mainly on domesticated species.

Hybridization

Breeding among recognized species.

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