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By the early ___________, continental drift had separated the New World
from the Old World.
Largest of Fayum anthropoids, roughly the size of a modern howler monkey (13-18
Bridges the gap between Eocene fossils
and succeeding Miocene hominoids
From what you know about primates
(chapters 6-7), what evidence indicates a fossil was a primate?
African forms (23–14 mya)
Especially from western Kenya, these hominoids are, in many ways,
European forms (16–11 mya)
From scattered localities in France, Spain, Italy, Greece, Austria,
Germany, and Hungary, most are quite derived.
Asian forms (16–7 mya)
The largest and most
varied group from Turkey through India/Pakistan and east to southern China,
most are highly derived
These hominoids are more closely
related to the ape-human lineage than Old World monkeys.
Mostly large-bodied hominoids, more akin to the lineages of orangutans, gorillas,
chimpanzees, and humans.
Most of the ________ forms discovered
are so derived that they are probably not ancestral to any living form.
One lineage that appears well established relates to __________ from Turkey and Pakistan. This form shows facial features similar to the modern orangutan, suggesting a fairly close evolutionary link.
Evidence of definite hominins from the Miocene has not been indisputably confirmed. However,
finds from Kenya, Ethiopia, and Chad suggest that hominins diverged sometime in the latter ________.
From what you know about primates
(chapters 6-7), what evidence indicates a fossil was a hominoid?
_________ is a set of learned behaviors;
it is transmitted from one generation to the next through learning and not by
biological or genetic means.
Describe Biocultural Evolution
- All aspects of human adaptation,
- including technology, traditions, language, religion, marriage patterns, and
- social roles.
_______________is defined as the study of early humans. They reconstruct the anatomy, behavior, and ecology of our ancestors:
It is a diverse multidisciplinary pursuit seeking to reconstruct every bit of information
possible concerning the dating, anatomy, behavior, and ecology of our hominin ancestors.
Name the Earliest recognized stone tool culture, including very simple tools, mostly small flakes
- 1. Relative dating
- 2. Stratigraphy
- 3. Flourine
- 4. Biostratigraphy
- 5. paleomagnetism
methods tell you that something is older or younger than something else
based on the law of superposition, which states that a lower layer is older than a higher one
Method used to date remains of bone
A pattern of evolution in which the rate of evolution in one functional system varies from that in other systems.
In hominin evolution, bipedal locomotion is a defining characteristic; other features such as brain development and behavior become significant in later stages
Mosaic Evolution of Modern Homo sapiens
Bipedal: shortened pelvis; larger body and legs; fingers and toes not as long
Mosaic Evolution of Early hominin
Bipedal: shortened pelvis; differences from later hominins, smaller body and long arms relative to legs; long fingers and toes; capable of considerable climbing
Mosaic Evolution of
Small compared to hominins, large compared to other primates;a fair degree of encephalization
Advantages of bipedalism:
Freed the hands for carrying objects and for making and using tools.
In the bipedal stance, animals have a wider view of the surrounding countryside.
Bipedal walking is an efficient means of covering long distances.
Structural and Anatomical Alterations That Made Walking Possible
Pelvis is comparatively much shorter and broader and extends around to the side, stabilizing the line of weight transmission from lower back to hip joint
Foot as stable support instead of a grasping limb
Elongated legs to increase the length of stride
Full extension of knee to maintain center of support directly under the body
- Small braincase
- Vertical face
- Huge browridge
- Hominin status questioned
The best-known, most widely distributed, and most diverse of the early African hominins are colloquially called ______________.
They all have large teeth, particularly the back teeth, with thick to very thick enamel on the molars.
Australopiths (4.2–1.2 mya)
These hominins have an established time range of over 3 million years, stretching back as early as 4.2 mya and not becoming extinct until apparently close to 1 mya.
Dated at between 3.5 and 3.7 mya.
Fossilized hominin footprints were found in an ancient volcanic bed.
Despite agreement that these individuals were bipedal, some researchers feel they were not bipedal in the same way as modern humans.
Name the three separate lineages of hominins living between 2.5 and 1 mya.
A ridge of bone that runs down the middle of the cranium.
This serves as the attachment for the large temporal muscles, indicating strong chewing.
Close to ___________, hominins expanded out of Africa into other areas of the Old World.
2 million years ago
Since the early hominin fossils have been found only in _____, it seems
that hominins were restricted to this continent for as long as 5 million
The First Dispersed Hominins where
were larger, and completely or almost completely living ina terrestrial habitat. They used elaborate stone tools.
The first hominin to expand into new regions of the Old World.
Homo erectus – A New Kind of Hominin
As a species, H. erectus existed for well over ________.
1 million years
We can understand its success as a hominid species based on behavioral
capacities (i.e. more elaborate tool use) and physical changes (i.e.
Grade refers to
grouping of organisms sharing a similar adaptive pattern.
Increase in body size and robustness
Changes in limb proportions Greater encephalization
Morphology of Homo erectus
Adult weight >100 lbs, average adult height of ca. 5 feet 6 inches
Sexually dimorphic, weight and height varied according to sex
Increased robusticity (heavily built body) that dominated hominin evolution until anatomically modern H. sapiens
Brain size closely linked with overall body size
A projection of bone in the back of the cranium where neck muscles attach; used to hold up the head.
Homo erectus evolved first in _______
According to the most recent evidence, the first modern Homo sapiens evolved in Africa around _______ years ago.
The majority of Neandertal fossils been found in _____________where they have been most studied.
Some Neandertal physical characteristics may have arisen as adaptations to a ______ environment.
During glacial peaks, much of western Europe would have been
cut off from the rest of Eurasia
The ________ epoch has been called the “Ice Age.”
The Upper Paleolithic culture period began in Western Europe about ________ years ago.
What is the benefit of an atlatl?
It is used to increase the force and distance of a spear throw
The genetic evidence from Neandertal remains that is used in studying most Neandertal fossils is in the form of
According to Partial Replacement Models, modern humans first appeared in Africa
and interbred with premodern populations of Eurasia, thus partially displacing them
What tool technology of premodern Homo sapiens is characteristic of the Middle Pleistocene
prepared core method or levallois technique
Upper Pleistocene premodern hominins that have their evolutionary roots in Western Europe include which group(s)?
neandertals and denisovans
Neandertal fossil remains have been found to reach as far back as ________ years ago.
130,000 years ago
Which excavations produced the most complete H. erectus skeleton ever found
Facial bones, a pelvis, and most of the limb bones, ribs, and vertebrae.
the west side of Lake Turkana at the site known as Nariokotome.
Asian and African Homo erectus: A Comparison
African-less robust cranial specimens
Asian-more robust cranial specimens
However, Daka cranium from Ethiopia looks like Asian forms and suggest Homo erectus is a widely distributed single species
Assigning the fossils to a particular species is problematic, based on the___________________.
fragmentary nature of the remains
Technological Trends in Homo erectus
Biface - stone worked on both sides and used to cut, scrape, pound, and dig.
Raw materials transported more consistently and for longer distances
Suggests foresight: knew they needed a stone tool in the future and carried what they regarded as useful
Expansion of the brain enabled H.erectus to develop sophisticated tools that span two stone tool industries:
Oldowan and Acheulian
Pertaining to a stone tool industry from the Lower and Middle Pleistocene.
Characterized by a large proportion of bifacial tools (flaked on both sides).
Multifunctional tools, including uses for butchery
What causes rickets?
an insufficient amount of vitamin D
What are disease-causing organisms such as bacteria and viruses called?
Which of following protects from ultraviolet radiation?
The World Heath Organization lists ______ as the world’s leading killer of adults.
states that bodies with increased mass or volume to surface area are optimal for cold climates
Studies have shown that UV radiation rapidly
depletes ______, which plays a crucial role in neural tube development of the embryo.
What is the term for the philosophy of “race
improvement” through the forced sterilization of some groups and the encouraged reproduction of others?
Mechanisms for radiating body heat include which of the following?
long term evolutionary changes
Categorizing people on the basis of skin color
has a long history and has been practiced by many peoples
The _________, often called the Ice
Age, was marked by advances and retreats of massive continental glaciations.
The portion of the Pleistocene epoch beginning 780,000 ya and ending 125,000 ya
The portion of the Pleistocene epoch beginning 125,000 ya and ending approximately 10,000 ya.
Climatic intervals when continental ice sheets cover much of the northern continents
Climatic intervals when continental ice sheets are retreating, eventually becoming much reduced in size.
Dispersal of Middle Pleistocene Hominins
- Europe becomes more permanently and
- densely occupied
- Mostly remained in areas previously
- occupied by Homo erectus
Middle Pleistocene Hominins: Terminology
- Premodern humans
- Transitional mix of ancestral and derived characteristics
- Homo heidelbergensis
- Paleospecies name for group that likely gave rise to Homo sapiens and Neandertals
Middle Pleistocene Hominins
Widely distributed in Africa, Asia and Europe, replacing earlier hominins in previously exploited habitats (or coexisting as in Southeast Asia)
Exhibit several H. erectus characteristics
Large face, projected brows, low forehead, and thick cranial vault
Increased brain size, rounded braincase, vertical nose, and reduced occipital
Middle Pleistocene Culture
Middle Pleistocene hominids built temporary structures.
exploited different food sources, fruits, vegetables, fish, seeds, nuts, and bird eggs, each in its own season.
exploited marine life, a new innovation in human evolution.
Neandertals: Premodern Humans of the Late Pleistocene
- Brain Size: Larger than H. sapiens today
- (1520 cm3 compared to 1300-1400 cm3 (perhaps adapted to
- cold climate).
Cranium: Large, long, low, and bulging at the sides.
Structure: Robust, barrel-chested, and powerfully muscled with shorter limbs than modern H. sapiens.
- Pertaining to an Upper Paleolithic
- industry found in France and Spain, containing blade tools and associated with Neandertals.
Suggestive of some cultural hybridization
Pertaining to the stone tool industry associated with Neandertals and some modern H. sapiens groups; also called Middle Paleolithic.
This industry is characterized by a larger proportion of flake tools than is found in Acheulian tool kits.
Used close-proximity spears for hunting (spear thrower and bow and arrow weren’t invented until the _______________.
Why should knowing the full genome of Neandertals help us learn something important
- Much of what makes humans unique is
- coded in genes that have been altered by evolution in the last few hundred thousand years.
By looking at Neandertal DNA, we can see which genes have been modified.
We can then begin to explain the biological bases of human intelligence and even perhaps the nature of consciousness.
Models of Human Origins
Regional Continuity: Multiregional Evolution
Populations, connected by gene flow, in
Europe, Asia, and Africa continued evolutionary development from _______________ to anatomically modern humans.
archaic H. sapiens
Complete Replacement Model: Recent African Evolution
Developed by British paleoanthropologists Christopher Stringer and Peter Andrews.
Proposes anatomically modern populations arose in Africa in the last 200,000 years.
- They migrated from Africa, completely
- replacing premodern populations in Europe and Asia.
- Does not account for the transition
- from premodern forms to H. sapiens anywhere except Africa.
Partial Replacement Model
Various perspectives suggest that modern humans originated in Africa and then, when their population increased, expanded out of Africa into other areas of the Old World.
This model claims that interbreeding occurred between emigrating Africans and resident premodern populations.
Are we all originally Africans?
- Yes, all the early hominids evolved
- first in Africa and migrated to other parts of the world only after several
- million years of evolutionary history confined solely to Africa.
In every meaningful evolutionary and biocultural aspect, we are all Africans.
- The next time you seriously consider
- the meaning of race, think about your African roots.
cultural and biological variations are inherited in the same way.
"race improvement" through forced sterilization of members of some groups and encouraged reproduction among others.
Since the ________, race has been used to refer to culturally defined groups.
A polytypic species is composed of local populations that differ in the expression of one or more traits.
Even within local populations, there’s a great deal of genotypic and phenotypic variation between individuals.
All contemporary humans are members of the same polytypic species, Homo sapiens.
Characteristics with different phenotypic expressions are called ______________.
A genetic trait is __________ if the locus that governs it has two or more alleles.
A cline is a
gradual change in the frequency of a trait or allele in populations dispersed over geographical space.
Scattered through the human genome are ____________, sites where DNA segments are repeated.
Human Biocultural Evolution
Humans live in cultural environments that are continually modified by their activities.
Evolutionary processes can be understood only within this cultural context
The increase in the frequency of the sickle-cell allele is a ________________ to an environmental change.
A ___________is the total complement of genes shared by the reproductive members of a population.
_________________are populations that
are isolated geographically and/or socially from other breeding groups.
- The mathematical relationship expressing the predicted distribution of alleles in populations;
- the central theorem of population genetics.
- Provides a tool to establish whether allele frequencies in a human population are changing
Factors that Act to Change Allele Frequencies
1.New variation (i.e., mutation)
2.Redistributed variation (i.e., gene flow or genetic drift)
3.Selection of “advantageous” allele combinations that promote reproductive success (i.e., natural selection).
Human variation is the result of adaptations to ___________________.
Physiological response to the environment operates at what two levels:
1.Long-term evolutionary changescharacterize all individuals within a population or species.
2.Short-term, temporary physiologicalresponse is called acclimatization.
A condition of stability within a biological system, maintained by the interaction of physiological mechanisms that compensate for changes.
Physiological responses to changes in the environment.
Responses may be temporary or permanent, depending on the duration of the environmental change and when it occurs.
Because it is under genetic influence, acclimatization is subject to natural selection and genetic drift.
The three major types of cells that can
be affected are
squamous cells, basal cells, and melanocytes.
Selective Advantages of Dark Skin
Protects from folate degradation
Especially important for pregnant mothers
Human Response to Heat
Long-term adaptations to heat evolved in our ancestors:
Bergmann's rule - body size tends to be greater in populations that live in cold environments.
In mammalian species, body size tends to be greater in populations that live in colder climates.
As mass increases, the relative amount of surface area decreases proportionately.
Because heat is lost at the surface, it follows that increased mass allows for greater heat retention and reduced heat loss.
In colder climates, shorter appendages, with increased mass-to-surface ratios, are adaptive because they are more effective at preventing heat loss.
Conversely, longer appendages, with increased surface area relative to mass, are more adaptive in warmer climates because they promote heat loss.
If a young man has Type A blood, this is his-?
Recent research suggests that a small amount of Neanderthal DNA is found in modern bhumanity's genome. This seems to illustrate what source of genetic variability?
Bergmann's rule suggests that-?
a heavier/larger body build will be found in colder climates
Human Response to Cold
- Short-term responses to
Metabolic rate and shivering
Capillaries near the skin’s surface widen to permit increased blood flow to the skin, vasodilation
Narrowing of blood vessels to reduce blood flow from the skin, vasoconstriction.
- Increases in metabolic rate to release
- energy in the form of heat.
Multiple factors that produce stress on the human body at higher altitudes:
Hypoxia (reduced available oxygen)
Intense solar radiation
Wind (which amplifies cold stress)
Caused by invading organisms such as bacteria, viruses, or fungi.
Throughout evolution, disease has exerted selective pressures on human populations.
Disease influences the frequency of certain alleles that affect the immune response.
Since the ______, the use of antibiotics has reduced mortality resulting from infectious disease.
Continuously present in a population.
Sufficient numbers of people must be present
Small bands of hunter-gatherers were not faced with continuous exposure to endemic disease
An extensive outbreak of disease affecting large numbers of individuals over a wide area; potentially a worldwide phenomenon.
One goal of the human genome project is to find _____variants associated with disease and to design treatments that target those genes.
variants cluster in certain populations, there have been efforts to identify ancestry to predict risks.
Name the Three major spurts are typical, including
first two trimesters in utero, first four years and the adolescent growth spurt
Adolescent Growth Spurt
Pronounced increase in growth rate at puberty, compared to fairly steady level maintained since about four years
- Western teenagers typically grow around
- 4 inches per year
Followed by decline in rate of growth until adult stature is achieved by late teens
Human Brain Growth
25% of its adult size at birth
50% at six months
75% at 2.5 years
90% at 2 years
95% at 10 years
Selective advantages of such an underdeveloped brain
Exit through narrow pelvis modified for bipedalism
Brain develops in stimulating, cultural context
Once adaptive, now maladaptive
Ability to store fat, an advantage when food availability often alternated between abundance and scarcity
“Feast or famine” biology incompatible with context of constant feast
- 80% of new cases of type 2 diabetes appearing between now and 2025 will
- be in developing nations
Type 2 diabetes, linked to poor diet and inadequate exercise, occurring in children as young as 4
- “epidemiologoical collision” in countries where malnutrition and infectious diseases
- collide with obesity
Other Factors Influencing Growth and Development: Genes and Environment
- Genetics – set the underlying limitations and potentials for growth and
- Environmental factors can influence growth and development, but an
- individual can not exceed their genetic potential.
Epigenome-Instructions that determine how genes are expressed in a cell
- Epigenetics-Changes in phenotype that are not related to changes in
- underlying DNA and that may result from the interaction between the genotype
- and the environment
Hormones – produced by endocrine glands
Growth hormone has an impact on almost every cell in the body.
Cortisol, elevated during stress, suppresses normal immune function during high levels
Glands responsible for secretion of hormones into the bloodstream
pituitary, thyroid, and adrenal glands, ovaries and testes
The Human Life Cycle
1.Prenatal begins with conception and ends with birth.
2.Infancy is period of nursing.
- 3.Childhood, or juvenile phase, is period from weaning to sexual maturity
- (puberty in humans.)
4.Adolescence is from puberty to the end of growth.
5.Adulthood is the completion of growth.
6.Menopause beginning one full year after the last menstrual cycle
Rapid growth seen during adolescent
growth spurt unique among ________
Women freed to provide high-quality care to grandchildren
Top 5 causes of death in the US are
heart disease, cancer, stroke, accidents, and chronic obstructive lung disease
the process of physiological decline in all systems of the body occurring toward the end of the life course
Genes that have more than one effect.
Genes that have different effects at different times in the life cycle.
May help to explain evolutionary reasons for aging, but do not explain the causes of senescence
Free radicals produced by mitochondria diminish efficiency of cellular energy production
Ultimately leads to organ failure
Repeated sequences of DNA at end of chromosomes
Get shorter as organisms age
Ultimately, impairs healthy cell division
Effects of Technology on the Brain
Our brains coevolved with technology and language development
- Contemporary technological change may
- be much more rapid than evolution can keep up with
- But, brains may be developmentally
- modified by using new technologies
Colloquial term for members of the tribe Hominini, which includes all bipedal hominoids back to the divergence with African great apes.
Pertaining to the concept that biology makes culture possible and that culture influences biology
Referring to all or part of the skeleton not including the skull. The term originates from the fact that in quadrupeds, the body is in back of the head; the term literally means “behind the head.”
Those hominoids including the great apes (orangutans, chimpanzees, gorillas) and hominins, as well as all ancestral forms back to the time of divergence from small-bodied hominoids (i.e., the gibbon lineage).
Nonbiological adaptations to the environment. This includes learned behaviors that can be communicated to others—especially from one generation to the next. Aspects of this capacity have been identified in our closest ape relatives.
Referring to animal remains; in archaeology, specifically refers to the fossil (skeletonized) remains of animals.
(chronos, meaning “time,” and metric, meaning “measure”) Referring to a dating technique that gives an estimate in actual numbers of years
Objects or materials made or modified for use by hominins. The earliest artifacts tend to be made of stone or occasionally bone
industry The earliest recognized stone tool culture, including very simple tools, mostly small flakes.
Study of the sequential layering of geological deposits. stratum (pl., strata) Geological layer.
thermoluminescence (TL) Technique
for dating certain archaeological materials that were heated in the past (such as stone tools) and that release stored energy of radioactive decay as light upon reheating.
A pattern of evolution in which the rate of evolution in one functional system varies from that in other systems. For example, in hominin evolution, the dental system, locomotor system, and neurological system (especially the brain) all evolved at markedly different rates.
Walking on two feet. Walking on two legs is the single most distinctive feature of the hominins.
A colloquial name referring to a diverse group of Plio-Pleistocene African hominins. Australopiths are the most abundant and widely distributed of all early hominins and are also the most completely studied
Pertaining to the Pliocene and first half of the Pleistocene, a time range of 5–1 mya. For this time period, numerous fossil hominins have been found in Africa.
Pertaining to a stone tool industry from the Early and Middle Pleistocene; characterized by a large proportion of bifacial tools (flaked on both sides). Acheulian tool kits are common in Africa, Southwest Asia, and western Europe, but they’re thought to be less common elsewhere. Also spelled Acheulean.
Pleistocene The epoch of the
Pleistocene The epoch of the Cenozoic from 1.8 mya until 10,000 ya. Frequently referred to as the Ice Age, this epoch is associated with continental glaciations in northern latitudes.
Middle Pleistocene The portion of the Pleistocene epoch beginning 780,000 ya and ending 125,000 ya.
Late Pleistocene The portion of the Pleistocene epoch beginning 125,000 ya and ending approximately 10,000 ya
Upper Paleolithic A cultural period usually associated
Upper Paleolithic A cultural period usually associated with modern humans, but also found with some Neandertals, and distinguished by technological innovation in various stone tool industries. Best known from western Europe, similar industries are also known from central and eastern Europe and Africa.
Mousterian Pertaining to the
Mousterian Pertaining to the stone tool industry associated with Neandertals and some modern H. sapiens groups; also called Middle Paleolithic. This industry is characterized by a larger proportion of flake tools than is found in Acheulian tool kits.
Aurignacian Pertaining to an
Aurignacian Pertaining to an Upper Paleolithic stone tool industry in Europe beginning at about 40,000 ya
Magdalenian Pertaining to the
the final phase of the Upper Paleolithic stone tool industry in Europe
Small, chisel-like tools with a pointed end; thought to have been used to engrave bone, antler, ivory, or wood.
The concept that phenomena, including various aspects of behavior (e.g., intelligence, values, morals) are governed by biological (genetic) factors; the inaccurate association of various behavioral attributes with certain biological traits, such as skin color
The philosophy of “race improvement” through the forced sterilization of members of some groups and increased reproduction among others; an overly simplified, often racist view that’s now discredited.
Referring to species composed of populations that differ in the expression of one or more traits.
Loci with more than one allele. Polymorphisms can be expressed in the phenotype as the result of gene action (as in ABO), or they can exist solely at the DNA level within noncoding regions.
A traditional land-clearing practice involving the cutting and burning of trees and vegetation. In many areas, fields are abandoned after a few years and clearing occurs elsewhere.
In adults, the continued production of lactase, the enzyme that breaks down lactose (milk sugar). This allows adults in some human populations to digest fresh milk products. The discontinued production of lactase in adults leads to lactose intolerance and the inability to digest fresh milk.
The study of the frequency of alleles, genotypes, and phenotypes in populations from a microevolutionary perspective.
The total complement of genes shared by the reproductive members of a population
Populations that are clearly isolated geographically and/ or socially from other breeding groups
The mathematical relationship expressing— under conditions in which no evolution is occurring—the predicted distribution of alleles in populations; the central theorem of population genetics.
In a physiological context, any factor that acts to disrupt homeostasis; more precisely, the body’s response to any factor that threatens its ability to maintain homeostasis.
A condition of balance, or stability, within a biological system, maintained by the interaction of physiological mechanisms that compensate for changes (both external and internal).
Physiological responses to changes in the environment that occur during an individual’s lifetime. Such responses may be temporary or permanent, depending on the duration of the environmental change and when in the individual’s life it occurs. The capacity for acclimatization may typify an entire population or species, and because it’s under genetic influence, it’s subject to evolutionary factors such as natural selection and genetic drift.
In early embryonic development, the anatomical structure that develops to form the brain and spinal cord.
A condition in which the arch of one or more vertebrae fails to fuse and form a protective barrier around the spinal cord. This can lead to spinal cord damage and paralysis.
A physiological mechanism that helps prevent the body from overheating. It occurs when perspiration is produced from sweat glands and then evaporates from the surface of the skin.
Expansion of blood vessels, permitting increased blood flow to the skin. Vasodilation permits warming of the skin and facilitates radiation of warmth as a means of cooling. Vasodilation is an involuntary response to warm temperatures, various drugs, and even emotional states (blushing)
Narrowing of blood vessels to reduce blood flow to the skin. Vasoconstriction is an involuntary response to cold and reduces heat loss at the skin’s surface.
Agents that transmit disease from one carrier to another. Mosquitoes are vectors for malaria, just as fleas are vectors for bubonic plague
Continuously present in a population
Pertaining to a zoonosis (pl., zoonoses), a disease that’s transmitted to humans through contact with nonhuman animals.
An epidemic that spreads through many populations and may affect people worldwide. Examples include HIV/ AIDS and the “Spanish flu” pandemic of 1918-1919.
Adolescent growth spurt
The period during adolescence when wellnourished teens typically increase in stature at greater rates than at other times in the life cycle.
Essential amino acids
The 9 (of 22) amino acids that must be obtained from the food we eat because they are not synthesized in the body in sufficient amounts
The instructions that determine how genes are expressed in a cell.
Changes in phenotype that are not related to changes in underlying DNA and that may result from the interaction between the genotype and the environment.
glands responsible for the secretion of hormones into the bloodstream.
The first menstruation in girls, usually occurring in the early to mid-teens.
Decline in physiological functioning usually associated with aging.
Genes that have more than one effect; genes that have different effects at different times in the life cycl
There are currently ___ billion humans living on this planet
The most recent epoch of the Cenozoic. Following the Pleistocene, it’s estimated to have begun 10,000 years ago