Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Gene Evolution - Fast or Slow?02:05

Gene Evolution - Fast or Slow?

8.3K
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
8.3K
Gene Evolution - Fast or Slow?02:05

Gene Evolution - Fast or Slow?

3.8K
3.8K
Frequency-dependent Selection01:21

Frequency-dependent Selection

24.3K
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.
24.3K
Replicative Cell Senescence02:15

Replicative Cell Senescence

4.5K
Replicative cell senescence is a property of cells that allows them to divide a finite number of times throughout the organism's lifespan while preventing excessive proliferation. Replicative senescence is associated with the gradual loss of the telomere — short, repetitive DNA sequences found at the end of the chromosomes. Telomeres are bound by a group of proteins to form a protective cap on the ends of chromosomes. Embryonic stem cells express telomerase — an enzyme that adds...
4.5K
Adaptive Mechanisms in Cancer Cells02:53

Adaptive Mechanisms in Cancer Cells

7.2K
Cancer cells accumulate genetic changes at an abnormally rapid rate due to the defects in the DNA repair mechanisms. From an evolutionary perspective, such genetic instability is advantageous for cancer development. Mutant cell lines accumulate a series of beneficial mutations that contribute to their progression into cancer.
Some of the advantages that cancer cells have on normal cells include - enhanced ability to divide without terminally differentiating, induce new blood vessel formation,...
7.2K
Life Histories01:29

Life Histories

23.1K
Overview
23.1K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Density Dependence, Senescence, and Williams' Hypothesis.

Trends in ecology & evolution·2020
Same author

How Does the Evolution of Universal Ecological Traits Affect Population Size? Lessons from Simple Models.

The American naturalist·2019
Same author

Antarctic fisheries: factor climate change into their management.

Nature·2018
Same author

Character Shifts of Prey Species That Share Predators.

The American naturalist·2018
Same author

The Adaptive Dynamics of Consumer Choice.

The American naturalist·2018
Same author

ON THE RELATIONSHIP BETWEEN QUANTITATIVE GENETIC AND ESS MODELS.

Evolution; international journal of organic evolution·2017
Same journal

Superorganismal Anisogamy: A Comparative Test of an Extended Theory.

Evolution; international journal of organic evolution·2026
Same journal

The role of microbial resource mutualists in plant adaptation to abiotic environments.

Evolution; international journal of organic evolution·2026
Same journal

Museum genomics links MC1R alleles to adaptive winter coat color polymorphism in the long-tailed weasel.

Evolution; international journal of organic evolution·2026
Same journal

Repeated evolution of iridescence and hindwing tails is associated with morphometric flight proxies in skipper butterflies.

Evolution; international journal of organic evolution·2026
Same journal

Temperature-dependent competition predicts contrasting outcomes of adjacent secondary contact zones in darters (Percidae:Etheostoma).

Evolution; international journal of organic evolution·2026
Same journal

Sex allocation of hermaphrodites in metapopulations with frequent population extinction and recolonization.

Evolution; international journal of organic evolution·2026
See all related articles

Related Experiment Video

Updated: Mar 1, 2026

Studying Age-dependent Genomic Instability using the S. cerevisiae Chronological Lifespan Model
08:46

Studying Age-dependent Genomic Instability using the S. cerevisiae Chronological Lifespan Model

Published on: September 29, 2011

16.1K

DOES INCREASED MORTALITY FAVOR THE EVOLUTION OF MORE RAPID SENESCENCE?

Peter A Abrams1

  • 1Department of Ecology and Behavioral Biology, University of Minnesota, 1987 Upper Buford Circle, St. Paul, Minnesota, 55108.

Evolution; International Journal of Organic Evolution
|June 2, 2017
PubMed
Summary
This summary is machine-generated.

Greater extrinsic mortality does not always accelerate aging. This study reveals that density-dependent population dynamics significantly influence the relationship between extrinsic mortality and senescence rates.

Keywords:
Agingdensity dependenceextrinsic mortalitylife historylife spansenescence

More Related Videos

A Quantitative Measurement of Reactive Oxygen Species and Senescence-associated Secretory Phenotype in Normal Human Fibroblasts During Oncogene-induced Senescence
13:59

A Quantitative Measurement of Reactive Oxygen Species and Senescence-associated Secretory Phenotype in Normal Human Fibroblasts During Oncogene-induced Senescence

Published on: August 12, 2018

8.6K
SA-β-Galactosidase-Based Screening Assay for the Identification of Senotherapeutic Drugs
07:39

SA-β-Galactosidase-Based Screening Assay for the Identification of Senotherapeutic Drugs

Published on: June 28, 2019

25.3K

Related Experiment Videos

Last Updated: Mar 1, 2026

Studying Age-dependent Genomic Instability using the S. cerevisiae Chronological Lifespan Model
08:46

Studying Age-dependent Genomic Instability using the S. cerevisiae Chronological Lifespan Model

Published on: September 29, 2011

16.1K
A Quantitative Measurement of Reactive Oxygen Species and Senescence-associated Secretory Phenotype in Normal Human Fibroblasts During Oncogene-induced Senescence
13:59

A Quantitative Measurement of Reactive Oxygen Species and Senescence-associated Secretory Phenotype in Normal Human Fibroblasts During Oncogene-induced Senescence

Published on: August 12, 2018

8.6K
SA-β-Galactosidase-Based Screening Assay for the Identification of Senotherapeutic Drugs
07:39

SA-β-Galactosidase-Based Screening Assay for the Identification of Senotherapeutic Drugs

Published on: June 28, 2019

25.3K

Area of Science:

  • Evolutionary biology
  • Gerontology
  • Population dynamics

Background:

  • The prevailing hypothesis suggests higher extrinsic mortality accelerates senescence.
  • Recent mammalian life table analyses challenge this long-held belief.
  • Extrinsic mortality is defined as age- and condition-independent mortality.

Purpose of the Study:

  • To theoretically analyze how extrinsic mortality influences senescence rates.
  • To explore the impact of different evolutionary and population dynamics assumptions.
  • To re-evaluate G. C. Williams's 1957 hypothesis on senescence and mortality.

Main Methods:

  • Theoretical modeling of senescence rates under varying mortality conditions.
  • Analysis of population dynamics, including density independence and dependence.
  • Examination of age-specific effects of density dependence on survival and reproduction.

Main Results:

  • Density-independent populations show no change in senescence rate due to extrinsic mortality.
  • In density-dependent, stable populations, extrinsic mortality's effect varies.
  • Effects can include increased, decreased, or mixed changes in senescence rates across ages.

Conclusions:

  • Williams's hypothesis holds under specific conditions, primarily when density dependence affects fertility without age bias.
  • Deviations from the hypothesis occur when density dependence impacts later-life survival/fertility or when nonextrinsic factors dominate mortality.
  • The interplay between extrinsic mortality and population regulation is complex and age-dependent.