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

What is Evolutionary History?02:35

What is Evolutionary History?

43.7K
Scientists record evolutionary history by analyzing fossil, morphological, and genetic data. The fossil record documents the history of life on Earth and provides evidence for evolution. However, both fossil and living organisms offer evidence that outlines Earth’s evolutionary history.
43.7K
Piecewise-Defined Functions01:28

Piecewise-Defined Functions

314
Piecewise defined functions are mathematical models where different expressions define a function over distinct intervals of the domain. These functions are useful for representing systems with varying behaviors depending on input values.For example, the function:  uses a linear rule for inputs less than or equal to –1 and a quadratic rule for values greater than –1. Although it has two formulas, it still defines a single function.Another common type is the absolute value...
314
Rules for Defining Functions01:29

Rules for Defining Functions

384
A relation is a function if each input x is associated with exactly one output y. For example, the equation      y = 2x + 5 defines a function because every value of x yields a unique y. However, x = y² + 1 is not a function of x, since a single x-value, such as x = 2, corresponds to two possible y-values: y = 1 and y = -1.The vertical line test helps determine whether a graph represents a function. If a vertical line intersects a curve more than once, the curve fails...
384
Evolutionary Psychology01:20

Evolutionary Psychology

1.0K
Evolutionary psychology explores the origins of human behavior and mental processes by framing them within the context of natural selection, a theory famously propounded by Charles Darwin. This field asserts that many behaviors common across human societies — ranging from instinctive fear reactions to complex social interactions — arose as evolutionary adaptations. These adaptations enhanced the survival and reproductive success of our ancestors, thereby becoming embedded in the...
1.0K
Criticisms of the Evolutionary Perspective01:23

Criticisms of the Evolutionary Perspective

380
In a study where individuals posing as strangers offered compliments and proposed casual sex to students, the responses differed significantly based on gender. Not a single woman accepted the proposal, while 70% of the men agreed. This outcome provides a useful scenario to explore through the lens of evolutionary psychology and social learning theory, highlighting the diverse perspectives on human sexual behaviors.
Evolutionary psychology provides one explanation for these findings, suggesting...
380
Evolutionary Relationships through Genome Comparisons02:54

Evolutionary Relationships through Genome Comparisons

7.1K
Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is that if two species share a common feature, it is likely encoded by the DNA sequence conserved between both species. The advent of genome sequencing technologies in the late 20th century enabled scientists to understand the concept of conservation of domains between species and helped them to deduce evolutionary relationships across diverse...
7.1K

You might also read

Related Articles

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

Sort by
Same author

Protein Surface Site Determines the Evolutionary Accessibility of Allosteric Regulation.

bioRxiv : the preprint server for biology·2026
Same author

Evolutionary divergence of nocturnin led to redox regulation in mammalian orthologs.

Biochemistry and biophysics reports·2026
Same author

Time-restricted feeding extends healthspan in both sexes and lifespan in male C57BL/6 J mice.

Nature aging·2026
Same author

Not all gut cellular circadian oscillators are food entrainable.

Proceedings of the National Academy of Sciences of the United States of America·2026
Same author

Circadian Alignment Through Time-Restricted Feeding: Implications for Health and Longevity.

Annual review of nutrition·2026
Same author

Systematic CRISPRi screening reveals genetic modulators of <i>E. coli</i> isoprenoid production.

bioRxiv : the preprint server for biology·2026

Related Experiment Video

Updated: Feb 13, 2026

Assessing Differences in Sperm Competitive Ability in Drosophila
09:34

Assessing Differences in Sperm Competitive Ability in Drosophila

Published on: August 22, 2013

15.1K

An evolutionary hotspot defines functional differences between CRYPTOCHROMES.

Clark Rosensweig1,2, Kimberly A Reynolds3,4, Peng Gao1

  • 1Department of Neuroscience, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA.

Nature Communications
|March 21, 2018
PubMed
Summary

Mammalian circadian clocks rely on feedback loops. Researchers discovered a CRY protein pocket that binds CLOCK/BMAL1, revealing how sequence changes impact clock speed and function.

More Related Videos

Spatial Multiobjective Optimization of Agricultural Conservation Practices using a SWAT Model and an Evolutionary Algorithm
11:53

Spatial Multiobjective Optimization of Agricultural Conservation Practices using a SWAT Model and an Evolutionary Algorithm

Published on: December 9, 2012

13.5K
A Method for Investigating Age-related Differences in the Functional Connectivity of Cognitive Control Networks Associated with Dimensional Change Card Sort Performance
09:01

A Method for Investigating Age-related Differences in the Functional Connectivity of Cognitive Control Networks Associated with Dimensional Change Card Sort Performance

Published on: May 7, 2014

10.6K

Related Experiment Videos

Last Updated: Feb 13, 2026

Assessing Differences in Sperm Competitive Ability in Drosophila
09:34

Assessing Differences in Sperm Competitive Ability in Drosophila

Published on: August 22, 2013

15.1K
Spatial Multiobjective Optimization of Agricultural Conservation Practices using a SWAT Model and an Evolutionary Algorithm
11:53

Spatial Multiobjective Optimization of Agricultural Conservation Practices using a SWAT Model and an Evolutionary Algorithm

Published on: December 9, 2012

13.5K
A Method for Investigating Age-related Differences in the Functional Connectivity of Cognitive Control Networks Associated with Dimensional Change Card Sort Performance
09:01

A Method for Investigating Age-related Differences in the Functional Connectivity of Cognitive Control Networks Associated with Dimensional Change Card Sort Performance

Published on: May 7, 2014

10.6K

Area of Science:

  • Molecular biology
  • Chronobiology
  • Evolutionary biology

Background:

  • Mammalian circadian clocks are regulated by transcription/translation feedback loops involving positive regulators (CLOCK/BMAL1) and repressors (CRYPTOCHROME 1/2 (CRY1/2) and PERIOD 1/2 (PER1/2)).
  • Understanding the structural basis of this regulation is crucial for deciphering clock mechanism and evolutionary variation.

Purpose of the Study:

  • To investigate the structural principles governing the regulation of mammalian circadian clocks.
  • To identify co-evolving residues within the CRY/PHL protein family using evolutionary sequence analysis.
  • To elucidate the functional role of identified regulatory interfaces in clock function.

Main Methods:

  • Evolutionary sequence analysis to identify co-evolving residues within the CRY/PHL protein family.
  • Identification of an ancestral secondary cofactor-binding pocket in repressive CRY proteins.
  • Site-directed mutagenesis to assess the impact of altered CLOCK/BMAL1-CRY1 binding on clock speed.
  • Comparative analysis of CRY1 and CRY2 interactions and the influence of PER2 co-expression.

Main Results:

  • An ancestral secondary cofactor-binding pocket was identified as a key interface in repressive CRYs, directly interacting with CLOCK and BMAL1.
  • Mutations weakening CLOCK/BMAL1-CRY1 binding accelerated the circadian clock, indicating sequence divergence modulates clock function.
  • Divergence between CRY1 and CRY2 at this pocket leads to distinct periodic outputs.
  • PER2 co-expression strengthens weaker CRY2-CLOCK/BMAL1 interactions, suggesting PER2 limits the CRY2-mediated repressive phase.

Conclusions:

  • This study reveals a novel regulatory mechanism in mammalian circadian clocks involving a CRY-mediated cofactor-binding pocket.
  • Sequence variations within this pocket significantly influence circadian clock speed and output.
  • The findings provide a mechanistic model for the evolution and functional diversity of circadian clock regulation.