Related Experiment Video

Updated: Aug 17, 2026

Experimental Manipulation of Body Size to Estimate Morphological Scaling Relationships in Drosophila
06:00

Experimental Manipulation of Body Size to Estimate Morphological Scaling Relationships in Drosophila

Published on: October 1, 2011

[Adaptive norm and stabilizing selection for anthropometric characters at birth]

O L Kurbatova, O K Botvin'ev, Iu P Altukhov

    Genetika
    |July 1, 1991
    PubMed

    Insights

    This study reveals that birth weight significantly impacts infant survival, with higher risks observed outside the adaptive norm. Neonatal mortality is strongly linked to birth weight, indicating intense natural selection in newborns.

    Area of Science:

    • Pediatric Medicine
    • Developmental Biology
    • Biostatistics

    Context:

    • Analysis of medical records from thousands of healthy and affected infants.
    • Focus on differential mortality and morbidity in newborns and infants.
    • Investigation of anthropometric traits at birth, including birth weight and body length.

    Purpose:

    • To define the adaptive norm for anthropometric traits at birth.
    • To estimate relative risk of mortality and morbidity as a function of birth weight and body length.
    • To quantify the intensity of stabilizing selection in the neonatal and infant periods.

    Summary:

    • Identified patterns of differential mortality and morbidity in infants based on birth weight and length.
    • Defined the adaptive norm as anthropometric ranges with lower-than-average mortality/morbidity rates.
    • Calculated stabilizing selection intensity for birth weight, finding it significantly higher in neonates than infants (1-12 months).

    Impact:

    • Over 50% of neonatal mortality can be attributed to stabilizing selection related to birth weight.
    • Highlights the critical role of birth weight in early life survival.
    • Provides quantitative insights into evolutionary selection pressures on human infants.

    More Related Videos

    Protocol for Assessing the Relative Effects of Environment and Genetics on Antler and Body Growth for a Long-lived Cervid09:09

    Protocol for Assessing the Relative Effects of Environment and Genetics on Antler and Body Growth for a Long-lived Cervid

    Published on: August 8, 2017

    Midface Hypoplasia and Cranial Base Morphology in Syndromic Craniosynostosis: A Comparative Analysis Study Using a Predictive Regression Model08:03

    Midface Hypoplasia and Cranial Base Morphology in Syndromic Craniosynostosis: A Comparative Analysis Study Using a Predictive Regression Model

    Published on: November 4, 2025

    Related Concept Videos

    Nature and Nurture01:10

    Nature and Nurture

    Many human characteristics, like height, are shaped by both nature—in other words, by our genes—and by nurture, or our environment. For example, chronic stress during childhood inhibits the production of growth hormones and consequently reduces bone growth and height. Scientists estimate that 70-90% of variation in height is due to genetic differences among individuals, and 10-30% of variation in height is due to differences in the environments that individuals experience, such as differences...
    Types of Selection01:46

    Types of Selection

    Natural selection influences the frequencies of particular alleles and phenotypes within populations in several different ways. Primarily, natural selection can be directional, stabilizing, or disruptive. Directional selection favors one extreme trait and shifts the population towards that phenotype while selecting against individuals displaying alternate traits. Stabilizing selection favors an intermediate trait with a narrow range of variation. Deviation from the optimal phenotype towards an...
    Frequency-dependent Selection01:21

    Frequency-dependent Selection

    When the fitness of a trait is influenced by how common it is (i.e., its frequency) relative to different traits within a population, this is referred to as frequency-dependent selection. Frequency-dependent selection may occur between species or within a single species. This type of selection can either be positive—with more common phenotypes having higher fitness—or negative, with rarer phenotypes conferring increased fitness.Positive Frequency-Dependent SelectionIn positive...
    Limits to Natural Selection01:38

    Limits to Natural Selection

    Organisms that are well-adapted to their environment are more likely to survive and reproduce. However, natural selection does not lead to perfectly adapted organisms. Several factors constrain natural selection.For one, natural selection can only act upon existing genetic variation. Hypothetically, redtusks may enhance elephant survival by deterring ivory-seeking poachers. However, if there are no gene variants—or alleles—for redtusks, natural selection cannot increase the prevalence of...
    Natural Selection and Adaptation01:15

    Natural Selection and Adaptation

    Natural selection, a fundamental concept in evolutionary biology, is the mechanism by which evolution is driven, favoring organisms that are best adapted to their environments. This process enhances their chances of survival and reproduction. Adaptation, a key outcome of this process, involves genetic modifications that optimize an organism's functionality under specific environmental challenges, such as extreme cold or thinner air at high altitudes.
    Beyond physical adaptations, psychological...
    Natural Selection and Mating Preferences01:06

    Natural Selection and Mating Preferences

    The principle of natural selection posits that organisms better adapted to their environment are more likely to survive and reproduce. This principle is closely intertwined with mating preferences, a key aspect of sexual selection, which evolutionary psychologists believe is driven by instincts to propagate one's genes. Such instincts significantly influence mating behaviors and preferences between genders.
    Females, due to their biological roles in conception, pregnancy, and nursing, inherently...