CARTA Glossary

Displaying 1 - 39 of 39 defined words for "We Are What We Ate: The Diets That Fueled Human Evolution". To see all CARTA defined words, please view the complete glossary.

Word	Definition	Related Vocabulary
12C/13C Isotope Ratio	Due to their different photosynthetic pathways, C3 and C4 plants have different ratios of 12C and 13C stable isotopes in their tissues. This ratio difference allows researchers to derive diet information from the fossilized tissue of animals, including human ancestors. Isotope ratios indicative of C3 plants suggest browsing from foliage while C4 isotope ratios suggest grazing. Please note: this information does not differentiate between a diet of eating C3 and C4 plants, eating the meat of an animal that consumed those plants, or a combination of the two.	Stable Isotope
Agriculture	A subsistence strategy that relies on domestication of species instead of hunting and gathering wild animals and plants.	Domestication, Hunting and gathering, Species
Alpha-amylase 1 (AMY1) gene	A gene that encodes salivary amylase, an enzyme produced primarily in the salivary glands that begins the digestion of starch in the mouth by breaking it down into smaller carbohydrates. Humans vary considerably in the number of copies of the AMY1 gene they carry, and higher AMY1 copy number is generally associated with greater salivary amylase production. This variation has been investigated as a possible adaptation to differences in dietary starch consumption.	Amylase, Gene
Amino acids	Organic compounds that are the building blocks of proteins and participate in a number of processes such as neurotransmitter transport and biosynthesis. Amino acids are encoded by the genome as different three nucleotide codes.	Genome, Nucleotides, Protein
Amylase	An enzyme that breaks down starch into glucose. It is the reason why starchy foods such as bread and potatoes have an appealing taste during chewing. Amylase is made by salivary glands (salivary amylase) and the pancreas (pancreatic amylase).	Enzyme
Anti-nutritional factors (ANFs)	Plant-derived compounds (e.g., phytates, oxalates, protease inhibitors, and tannins) that bind nutrients or inhibit digestive enzymes, reducing nutrient absorption.
Apes	A branch of “old world” primates characterized by the lack of a tail due to a mutation of the TBXT gene. Apes consist of the families, Hylobatidae (“lesser apes”: gibbons and siamangs) and Hominidae (“great apes”: orangutans, gorillas, chimpanzees, bonobos, and humans).	Bonobos (Pan paniscus), Chimpanzees (Pan troglodytes), Great apes, Primates
Atherosclerosis	Build-up of cholesterol (plaque) and inflammation in the lining of blood vessels. Plaque can narrow or block arteries and may rupture, causing blood clots that restrict blood flow. Named after its gruel-like appearance (athero = gruel).
Atherosclerotic cardiovascular disease (ASCVD)	A group of diseases caused by atherosclerosis. ASCVD includes coronary heart disease, heart attack, ischemic stroke, and peripheral artery disease.	Atherosclerosis
Australopithecines	Literally meaning “southern apes,” Australopithecines are early African hominins (ca. 4–2 million years ago) with endocranial volumes comparable to those of extant chimpanzees.	Hominin
Australopithecus	A genus of extinct hominins dating ~4 mya to 2 mya, and found primarily in eastern and southern Africa. Homo may have evolved from a late australopithecine. Australopithecine brain size is ~35% of the size of the modern human brain. Most species were short in stature, although sexual dimorphism was pronounced. Some examples of australopithecines: A. anamenis: Kenya and Ethiopia. ~4 mya. A. afarensis: Eastern Africa. Most famous example is “Lucy.” ~3.9 mya to 2.9 mya. A. bahrelghazali: Central Africa. ~3.6 mya A. africanus: Southern Africa. ~3.3 mya to 2.1 mya. A. garhi: Ethiopia. Possible transitional stage between Australopithecus and Homo. ~2.5 mya. *A. boisei: East Africa. Robust australopithecine. There is debate as to which genus they belong, Australopithecus* or Paranthropus. ~2.4 to 1.4 mya. A. sediba: South Africa. Possible transitional stage between Australopithecus and Homo. ~2 mya.	Genus, Hominin, Homo
Bacteria	A type of prokaryotic microorganism. Unlike eukaryotes, bacterial cells do not contain a nucleus and rarely harbour membrane-bound organelles. Bacteria were among the first life forms to evolve on Earth, and can be found in most every habitat, including soil, water, acidic hot springs, radioactive waste, the deep biosphere of the earth’s crust, and in and on other living organisms as symbionts and parasites. Bacteria can be beneficial, such as those comprising the gut flora, or pathogenic and cause infectious disease. However, the vast majority of the bacteria in the body are rendered harmless by the protective effects of the immune system.	Eukaryotes, Infectious disease, Parasite, Pathogenicity, Prokaryotes, Symbiont
Bioavailability	The proportion of an ingested nutrient that is absorbed and made available for physiological use.
Bonobos (Pan paniscus)	One of the two species comprising the genus, Pan, having branched from chimpanzees ~1 million years ago. Sometimes referred to as “pygmy chimpanzee.” Bonobos, compared to chimpanzees, are more gracile, have female social dominance, relatively long legs, pink lips, a dark face, a “tail-tuft” through adulthood, and parted long head hair. The species is omnivorous and inhabits primary and secondary forests, including seasonally inundated swamp forests. The bonobo is found in a 500,000 km² (190,000 sq mi) area of the Congo Basin, only south of the Congo River, in the Democratic Republic of the Congo. Due to political instability, little field work in their natural habitat has been performed. Most behavioral knowledge is a result of studies of captive bonobos.	Chimpanzees (Pan troglodytes), Genus, Species
Cancer	A disease caused by an uncontrolled division of abnormal cells in a part of the body. Cancer is considered “normal development spun out of control” – Steve Frank, from CARTA’s May 2025 symposium, Mismatch: Human Origins and Modern Disease.
Carbohydrate	A class of organic molecules composed primarily of carbon, hydrogen, and oxygen that includes sugars, starches, and dietary fiber. Carbohydrates serve as an important source of energy and, in plants, also function as structural and energy-storage compounds.	Starch
Carnivore	An organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging.
Carnivore guild	A group of carnivorous species in an ecosystem that share similar ecological roles by hunting, scavenging, or consuming similar animal prey. Species within a carnivore guild may compete for food and may differ in their hunting strategies, body size, habitat use, and preferred prey.
Chimpanzees (Pan troglodytes)	One of the two species comprising the genus, Pan, having branched from bonobos ~1 million years ago. Sometimes referred to as “common chimpanzees”. Native to sub-Saharan Africa, chimpanzees are found in and around the Congo Basin (north of the Congo River) and throughout West Africa. Chimpanzees are divided into four subspecies, based on appearance and distribution. Compared to bonobos, chimpanzees are somewhat larger, more aggressive, and exhibit male social dominance.	Bonobos (Pan paniscus), Genus, Species
Chromatin	A complex of DNA and proteins (histone and adaptor proteins) forming chromosomes.	Chromosome, Deoxyribonucleic acid (DNA), Protein
Chromosome	A discrete strand of tightly packaged chromatin.	Chromatin
Cognition	The mental action or process of acquiring knowledge and understanding through thought, experience, and the senses.
Cooking hypothesis	The evolutionary hypothesis proposed by Wrangham and Carmody that habitual cooking played a major role in human evolution by making food easier to digest, increasing the amount of energy available from food, and reducing the time and effort required to process and consume it. The hypothesis proposes that these energetic and nutritional advantages may have contributed to changes in human anatomy, physiology, behavior, and life history, including the evolution of our relatively large brains.
Cranial capacity	The volume of the interior of the cranium. Cranial capacity is used as a rough indicator of brain size and is typically measured in cubic centimeters (cc or cm3).
Culture	Behavior and norms that are shared, learned, and socially transmitted.
Cumulative culture	The process by which social learning allows for the accumulation of modifications over generations, leading to tools, beliefs, or behaviors that are more complex than any single individual could invent alone. See culture.	Culture
Cytidine monophospho-N-acetylneuraminic acid hydroxylase (CMAH) gene	The human lineage lost the function of the CMAH gene over 2 million years ago that caused human cells to both lack Neu5Gc and carry an excess of Neu5Ac.	N-acetylneuraminic acid (Neu5Ac), N-glycolylneuraminic acid (Neu5Gc)
Denisovans	An extinct hominin population contemporary with Neanderthals that hybridized with ancient humans and Neanderthals. Knowledge of Denisovan morphology is limited to two small fossils found in Siberia, a jaw in Tibet, a skull in China, a mandible in Taiwan, and an arm bone from southern China.	Hominin, Neanderthals
Dental Calculus	Calcified dental plaque, provides information on diet, disease, health, microbiome and protects the genetic information within the tooth from degradation.
Deoxyribonucleic acid (DNA)	The molecule of inheritance, which consists of sequences of the four nucleotide bases: Adenine, Thymine, Guanine, and Cytosine.	Molecule, Nucleotides, Sequence
Digestive system	The organs of the body that are involved in the breakdown and absorption of food, and elimination of wastes. This includes the mouth, pharynx (throat), esophagus, stomach, small intestine, large intestine, rectum, and accessory digestive organs such as the salivary glands, liver, gallbladder, and pancreas.
DNA sequence	The specific order of the nucleotide bases along a strand of DNA.	Deoxyribonucleic acid (DNA), Nucleotides
Domestication	The process of artificial selection by humans for desired traits of plants, animals, fungi, and microorganisms. This implies the complete control of the reproduction of those species.	Species
Enzyme	Proteins that catalyze chemical reactions inside and outside cells.	Protein
Eukaryotes	Organisms whose cells have a nucleus enclosed within membranes.
Evolution	The process by which populations change over time through random mutation and natural selection. Evolution occurs at the level of populations, not individuals, and involves genetic changes that are passed down through generations.
Expensive Tissue Hypothesis	The proposal (Aiello & Wheeler, 1995) that reductions in metabolically costly tissues, particularly the gastrointestinal tract, can contribute to the energetic budget required for brain expansion. Current work treats this as one of several compensating factors, alongside dietary shifts, fat storage, extended life history, and cooperative provisioning, rather than a strict one-for-one trade-off.
External fermentation	Microbial breakdown of organic matter occurring outside the body, prior to ingestion, in contrast to fermentation within the digestive tract.
External fermentation hypothesis	An evolutionary hypothesis proposing that humans gained an important energetic advantage by fermenting foods outside the body before consuming them. Fermentation can partially break down complex carbohydrates and other food components, potentially improving digestibility, nutrient availability, preservation, and palatability while reducing some of the metabolic costs of digestion. The hypothesis suggests that external fermentation may have complemented other forms of food processing, including cooking, and may have been particularly important in human evolution because humans lack the extensive internal fermentation chambers found in many other mammals. The hypothesis is particularly associated with David A. S. Lieberman.