Name: heritability and the environment
Uploaded: 2024-10-24T14:03:06.000Z
Duration: 1 min 6 s
Channel: JoVE

K12 Standards

Arizona Science Standards

High School

Life Science

HS+B.L3

HS+B.L3U1.10

Heritability

L’héritabilité mesure l’influence génétique sur des traits ou des caractéristiques physiques telles que la taille ou la couleur des yeux.
L’héritabilité peut varier en fonction du groupe et des conditions dans lesquelles ils vivent.
Par exemple, la taille humaine est héréditaire à 90 %, mais les nutriments et l’exercice l’influencent de manière significative.
Lorsque tous les membres d’un groupe, comme tous les enfants de cette famille, vivent dans un environnement similaire, les différences dans leurs traits, comme la taille ou la personnalité, sont plus susceptibles de provenir de leurs facteurs génétiques.
À l'inverse, si l'un des enfants est plus actif physiquement et a une alimentation plus saine, les différences entre les caractéristiques physiques des frères et sœurs peuvent être dues à des facteurs environnementaux plutôt que génétiques.
Les données historiques sur les traits physiques illustrent davantage l’impact de l’environnement. Par exemple, la taille moyenne mondiale des hommes et des femmes a augmenté d’environ 10 cm au cours des 100 dernières années, ce qui reflète l’amélioration de la nutrition et des soins de santé.

héritabilité

L'héritabilité est un concept statistique qui mesure dans quelle mesure les différences génétiques entre individus contribuent aux variations des traits au sein d'une population. Il s'agit d'une idée fondamentale en génétique, souvent sujette à des interprétations erronées. L'héritabilité est exprimée en pourcentage, reflétant la proportion de variation d'un trait spécifique au sein d'une population qui peut être attribuée à des différences génétiques. Cependant, il est important de comprendre que l'héritabilité ne détermine pas le degré de « contribution génétique » d'un trait, et qu'elle n'est pas non plus constante dans différentes populations ou différents contextes environnementaux.

L’héritabilité d’un trait peut varier considérablement en fonction de la population étudiée et des conditions environnementales spécifiques. Cette variabilité souligne que l’héritabilité dépend intrinsèquement du contexte. Par exemple, dans une population où les individus vivent dans des conditions environnementales très similaires, les différences concernant un trait comme la taille sont plus susceptibles d’être attribuées à des variations génétiques, ce qui se traduit par une estimation de l’héritabilité plus élevée. En revanche, dans une population présentant une diversité de conditions environnementales, le même trait peut afficher une héritabilité plus faible, car les facteurs environnementaux jouent un rôle plus significatif dans les variations observées.

De plus, une héritabilité élevée ne signifie pas que le développement d’un trait n’est pas affecté par les influences environnementales. Même les traits ayant des composantes héréditaires importantes, comme le QI, peuvent être considérablement modifiés par des changements dans les conditions environnementales. Cela met en évidence l’interaction dynamique entre la génétique et l’environnement. Par exemple, la mise en œuvre de programmes éducatifs enrichis peut stimuler les capacités cognitives, ce qui indique que les modifications environnementales peuvent influencer les traits ayant de fortes bases génétiques.

Les changements historiques dans des caractéristiques telles que la stature physique illustrent également ce concept. La taille moyenne de diverses populations a augmenté au cours du siècle dernier, principalement en raison des améliorations de la nutrition et des soins de santé plutôt que d’altérations génétiques au sein de ces populations. Cette augmentation, observée sous la forme d'une hausse de 8,89 centimètres de la taille moyenne entre 1896 et les années 1990, souligne l'impact significatif des améliorations environnementales sur une caractéristique ayant des déterminants génétiques importants.

De plus, les recherches portant sur des individus ayant des antécédents génétiques similaires, mais évoluant dans des environnements allant du minimal au très favorable, illustrent une variabilité considérable des traits. Ces études soulignent que la génétique fournit le cadre, mais que les facteurs environnementaux façonnent de manière significative les traits physiques et comportementaux des individus. Comprendre l'interaction entre la génétique et l'environnement est essentiel pour appréhender l'héritabilité et son rôle dans le développement des traits au sein des populations.

Héritabilité

L’héritabilité mesure l’influence génétique sur des traits ou des caractéristiques physiques telles que la taille ou la couleur des yeux.
L’héritabilité peut varier en fonction de ...

Education

Enseignement

JoVE Core

Introduction to Psychology

Introduction à la psychologie

Unit 1

Unité 1

Biopsychology

Biopsychologie

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

heritability and the environment

Heritability describes how genetic differences contribute to trait variation in a population. It is a statistical measure, so it shows how much of the spread in a trait can be linked to genes across a group. It does not tell you how “genetic” a trait is in an individual person.

Heritability is usually expressed as a percentage. That percentage can change depending on which population is studied and what environmental conditions are present. This means heritability is context-dependent, not fixed for every group or setting.

When people in a population live in very similar environments, genetic differences may explain more of the variation in a trait. In that case, the heritability estimate can be higher. Height is one example often used to show this pattern.

When a population has wider environmental differences, the same trait may show lower heritability. Environmental factors then play a larger role in the variation that is seen. A high heritability estimate still does not mean the trait is untouched by the environment.

Traits with strong heritable components can still change when the environment changes. IQ is one example, because enriched educational programs can improve cognitive ability. The transcript also notes that average height has increased over the last century mostly because of better nutrition and healthcare, not because of genetic change.

The rise in average height was about 3.5 inches from 1896 to the 1990s. Studies of people with similar genetic backgrounds also show large differences when they grow up in environments that range from minimal to highly supportive. These examples show that genes set a framework, but the environment helps shape the final trait.

Heritability and the Environment

introduction to biological bases of psychology

introduction-to-biological-bases-of-psychology

Biological Factors Shaping Behavior and Mind

Biopsychology connects biology and psychology by showing how the body influences behavior and mental processes. It focuses on the nervous system, neurotransmitters, hormones, genetics, and evolutionary ideas. Together, these areas help explain why people think, feel, and act the way they do. The nervous system is the main foundation of biopsychology. It has two parts: the central nervous system, or CNS, and the peripheral nervous system, or PNS. The CNS includes the brain and spinal cord and...

nervous system

Nervous System: CNS, PNS, and Reflexes

The nervous system helps the body sense, move, and respond. It works through a network of nerve cells that carry signals around the body. This system has two main parts: the central nervous system and the peripheral nervous system. The central nervous system, or CNS, includes the brain and spinal cord. The brain acts as the body’s control center. It processes sensory information and helps coordinate responses. The spinal cord serves as a major pathway for signals between the brain and the rest...

neurons as communicators of the brain

Neuron Parts and Signal Transmission

Neurons are the cells that carry information through the brain and nervous system. They use electrical and chemical signals to help control body functions, from heartbeat regulation to complex thinking. Their structure is built for fast, efficient communication. The cell body, or soma, is the neuron’s control center. It contains the nucleus, which holds the cell’s genetic material and helps maintain the neuron’s health and function. The cytoplasm around it contains organelles that make...

neuronal communication

How Neurons Send Signals

Neurons send signals through electrochemical communication that supports brain and nervous system function. A key part of this process is the action potential, a rapid electrical change that starts when the neuron’s internal charge rises above a threshold. That signal then travels along the axon to the axon terminal, where it is ready to pass to another neuron. The connection point between two neurons is called a synapse. Synapses can be electrical or chemical, and each type moves information...

neurotransmitters

Brain Chemicals That Shape Mood and Movement

Neurotransmitters are chemical messengers that help neurons communicate. They play a major role in nervous system function, as well as in mood, movement, sleep, and social behavior. Serotonin is made in the brain and intestines. It is linked to well-being and happiness, and it helps regulate mood, appetite, and sleep. When serotonin levels are out of balance in the brain or in peripheral sites, depression and sleep problems can occur. Dopamine is produced in several brain areas, including the...

cerebral hemispheres

How the Brain’s Two Halves Work

The brain’s two cerebral hemispheres work together to process information and control the body. The left and right hemispheres are linked by the corpus callosum, a large bundle of nerve fibers. This connection lets the two sides share sensory and motor information, with each hemisphere controlling the opposite side of the body. The hemispheres are also specialized for different tasks. This is called lateralization, which means certain functions are handled more strongly by one side than the...

lobes of the cerebrum

How Brain Lobes Shape Perception

The cerebral cortex is divided into two hemispheres, and each hemisphere has four lobes: frontal, parietal, temporal, and occipital. Together, these lobes support the brain’s main cognitive and sensory jobs. They work as a team to help you think, feel, move, and respond to the world. The frontal lobe sits behind the forehead and acts as a control center for personality, intelligence, and voluntary muscle movement. It also contains the prefrontal cortex, a region that helps with planning,...

spinal cord

Spinal Cord Nerves and Reflexes

The spinal cord is a major part of the central nervous system. It runs from the base of the brainstem to the lumbar region of the vertebral column. It helps keep the body stable and carries signals between the brain and the rest of the body. The spinal cord sits inside the bony spine for protection. It is divided into 30 segments that match the vertebrae. Each segment connects to a specific body region through paired spinal nerves. These spinal nerves are grouped by where they leave the...

lateralization

Brain Hemisphere Specialization

Brain hemisphere specialization divides mental tasks between the left and right sides of the brain. This split can improve neural efficiency and support more complex human abilities. Each hemisphere tends to handle the work it does best, which helps cognitive processing run more smoothly. The left hemisphere is especially strong in logic and language-related tasks. It supports analytical thinking, which means breaking a problem into parts and solving it step by step. This is important for...

human genetics

Genes, Behavior, and Mental Health

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Chromosomes, DNA, and Inherited Traits

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genetic variation

How Alleles Shape Inherited Traits

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behavioral genetics and its designs

How Behavior Genetics Studies Inheritance

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organization of the brain

Brain Regions and Their Key Functions

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evolutionary psychology

Evolutionary Psychology and Human Behavior

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neuroplasticity

How the Brain Rewires Itself

Neuroplasticity is the brain’s ability to change its structure and function in response to learning, experience, or injury. It allows neural circuits to reorganize over time. This flexibility supports lifelong development and adaptation. One part of this change begins when dendrites and axons grow. Dendrites receive signals, and axons send them. As they grow, the brain’s circuitry becomes more complex and can support more connections. Next, synaptogenesis occurs. Synaptogenesis is the...

brain imaging

Brain Scanning Techniques

Brain scanning techniques help scientists and doctors see the structure and activity of the human brain. These methods support the diagnosis, study, and treatment of neurological and psychiatric disorders. The main techniques include computerized axial tomography, or CT, positron-emission tomography, or PET, magnetic resonance imaging, or MRI, functional magnetic resonance imaging, or fMRI, and transcranial magnetic stimulation, or TMS. CT scans use X-ray technology to build detailed...

the endocrine system

Endocrine Glands and Hormone Signals

The endocrine system is a network of glands that send hormone signals through the body. Hormones are chemical messengers that help control many body functions. They enter the bloodstream and travel to cells with the right receptors, or target sites, so the signal can be received. Because of this, hormone effects are widespread, unlike the more localized effects of neurotransmitters. This signaling helps the body keep a stable internal environment, called homeostasis. Several major glands...

somatosensory, motor, and association cortex

somatosensory-motor-and-association-cortex

Brain Cortex Areas for Sensation and Movement

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major hormones and their functions

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Hormones are chemical messengers made by endocrine glands. They help control body functions and keep internal conditions stable. When hormone levels shift too far up or down, normal body processes can be disrupted. Several major hormones have clear roles in the body. Oxytocin is made in the hypothalamus and released by the pituitary gland. It supports social bonding, childbirth, and lactation. Low oxytocin can affect social interaction and stress response, and it may contribute to depression.

inheritance

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gene-environment interactions

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heritability

Heritability describes how genetic differences contribute to trait variation in a population. It is a statistical measure, so it shows how much of the spread in a trait can be linked to genes across a group. It does not tell you how “genetic” a trait is in an individual person. Heritability is usually expressed as a percentage. That percentage can change depending on which population is studied and what environmental conditions are present. This means heritability is context-dependent, not...

natural selection and adaptation

Adaptation in Changing Environments

Natural selection explains how organisms become better suited to their environments over time. It favors individuals with traits that improve survival and reproduction. Adaptation is the result. It includes genetic changes that help an organism function in specific conditions, such as extreme cold or thinner air at high altitudes. Adaptation is not only physical. Psychological adaptation also helps organisms, especially humans, succeed in their surroundings. These responses come from both...

natural selection and mating preferences

How Selection Shapes Mate Choice

Natural selection and mating preferences work together to shape how organisms survive and reproduce. Natural selection favors traits that help an organism fit its environment. Mating preferences are part of sexual selection, which influences who mates with whom and how genes are passed on. Evolutionary psychologists argue that these preferences are tied to instincts that support reproduction. For females, conception, pregnancy, and nursing create a strong need to choose mates who can offer...

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Social Learning vs. Evolutionary Psychology

Social learning theory and evolutionary psychology offer two different ways to explain sexual behavior. A study in which strangers gave students compliments and then asked for casual sex showed a clear gender gap. None of the women said yes, while 70% of the men agreed. Evolutionary psychology explains this result by arguing that natural selection may have shaped women to be more selective about sexual partners. From this view, selectivity can help improve survival and reproductive success. It...

key terms and concepts

Learn how heritability measures genetic differences in a population, why it changes with environment, and how nutrition, education, and healthcare affect traits.

Heritability and the Environment | JoVE K12

JoVE Core Introduction to Psychology offers an engaging learning experience on the fundamental principles of psychology through concise video lessons. Students will explore important topics such as cognitive processes, emotional regulation, and neural mechanisms, establishing a strong foundation in the study of the mind and human behavior. This series provides an accessible and captivating approach to grasp the essential concepts of the discipline.

introduction to psychology

Florida Department of Education

SC.912.L.14

SC.912.L.14.6

new-york-state-science-learning-standards

New York State Science Learning Standards

Natural Selection and Evolution

HS-LS4-3.

What is Population Genetics?

A population is composed of members of the same species that simultaneously live and interact in the same area. When individuals in a population breed, ...

Hardy-Weinberg Principle

Diploid organisms have two alleles of each gene, one from each parent, in their somatic cells. Therefore, each individual contributes two alleles to the ...

Mutation, Gene Flow, and Genetic Drift

In a population that is not at Hardy-Weinberg equilibrium, the frequency of alleles changes over time. Therefore, any deviations from the five conditions ...

Genetic Variation

Genetic variation stems from differences in DNA sequences among individuals, which are essential for species adaptation and evolution.
Genetic variations ...

Heritability measures the genetic influence on traits or physical characteristics such as height or eye color.
Heritability can vary depending on the ...

Natural Selection and Adaptation

Natural selection drives evolution by supporting organisms that are best adapted to their environments, enhancing their survival and reproduction rates.
...

Natural Selection and Mating Preferences

The principle of natural selection suggests that organisms better adapted to their environment are more likely to survive and reproduce.
Evolutionary ...

Use mathematics and computational thinking to explain the variation that occurs through meiosis and calculate the distribution of expressed traits in a population.

Genomic DNA in Prokaryotes

The genome of most prokaryotic organisms consists of double-stranded DNA organized into one circular chromosome in a region of cytoplasm called the ...

Genomic DNA in Eukaryotes

Eukaryotes have large genomes compared to prokaryotes. To fit their genomes into a cell, eukaryotic DNA is packaged extraordinarily tightly inside the ...

The DNA Helix

Overview

Deoxyribonucleic acid, or DNA, is the genetic material responsible for passing traits from generation to generation in all organisms and most ...

DNA Packaging

Overview

Eukaryotes have large genomes compared to prokaryotes. In order to fit their genomes into a cell, eukaryotes must pack their DNA tightly inside ...

Organization of Genes

Overview

The genomes of eukaryotes can be structured in several functional categories. A strand of DNA is comprised of genes and intergenic regions. ...

Karyotyping

Describing the number and physical features of chromosomes can reveal abnormalities that underlie genetic diseases. This description is facilitated by ...

RNA Structure

Overview
The basic structure of RNA consists of a five-carbon sugar and one of four nitrogenous bases. Although most RNA is single-stranded, it can form ...

RNA Stability

Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations ...

Types of RNA

Overview
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs ...

MicroRNAs

MicroRNA (miRNA) are short, regulatory RNA transcribed from introns&mdash;non-coding regions of a gene&mdash;or intergenic regions&mdash;stretches of DNA ...

Transcription

Overview
Transcription is the process of synthesizing RNA from a DNA sequence by RNA polymerase. It is the first step in producing a protein from a gene ...

Translation

Lesson: Translation
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following ...

Bacterial Transformation

In 1928, bacteriologist Frederick Griffith worked on a vaccine for pneumonia, which is caused by Streptococcus pneumoniae bacteria. Griffith studied two ...

What is Gene Expression?

Overview
Gene expression is the process in which DNA&nbsp;directs the synthesis of functional products, that is, proteins. Cells can regulate gene ...

The Central Dogma

Overview

The central dogma of biology states that information encoded in the DNA is transferred to messenger RNA (mRNA), which then directs the synthesis ...

Transcription Factors

Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of ...

Construct an explanation for how the structure of DNA and RNA determine the structure of proteins that perform essential life functions.

HS+B.L3U1.11

Mutations

Mutations are changes in the sequence of DNA. These changes can occur spontaneously or they can be induced by exposure to environmental factors. Mutations ...

genome-size-and-the-evolution-of-new-genes

Genome Size and the Evolution of New Genes

evolutionary-relationships-through-genome-comparisons

Evolutionary Relationships through Genome Comparisons

Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is ...

Genome Copying Errors

DNA replication is a well-evolved process that copies millions of base pairs with high fidelity during each cell division. Occasionally a wrong base or a ...

Multi-species Conserved Sequences

Next-generation sequencing technologies have created large genomic databases of a variety of animals and plants. Ever since the human genome project was ...

Gene Duplication and Divergence

The seminal work of Ohno in 1970 popularized the idea of gene duplication and divergence. DNA sequence comparison studies reveal that a large portion of ...

Exon Recombination

The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new ...

Analyze and interpret data on how mutations can lead to increased genetic variation in a population.

HS+B.L3U1.12

Heritability and the Environment

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