Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Speciation Rates

Speciation Rates

Speciation can proceed at markedly different rates, and evolutionary biologists commonly describe these differences through the models of gradualism and punctuated equilibrium. Both patterns explain how new species arise, but they differ in the tempo and continuity of evolutionary change. In both cases, evolutionary change arises from heritable variation within populations, with natural selection often shaping traits that improve survival and reproduction under specific environmental conditions.

Limits to Natural Selection

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...

Conservation of Declining Populations

Conservation of Declining Populations

Conservation of declining population focuses on ways of detecting, diagnosing, and halting a population decline. The approach uses methods to prevent populations from going extinct.

Genetics of Speciation

Genetics of Speciation

Speciation is the evolutionary process resulting in the formation of new, distinct species—groups of reproductively isolated populations.The genetics of speciation involves the different traits or isolating mechanisms preventing gene exchange, leading to reproductive isolation. Reproductive isolation can be due to reproductive barriers that have effects either before or after the formation of a zygote. Pre-zygotic mechanisms prevent fertilization from occurring, and post-zygotic mechanisms...

The Evidence for Evolution

The Evidence for Evolution

Genetic variations accumulating within populations over generations give rise to biological evolution. Evolutionary changes can result in the formation of novel varieties and entire new species. These changes are responsible for the diverse forms of life inhabiting the planet. The evidence for evolution suggests that all living organisms descended from common ancestors.The collection of fossils within sedimentary rocks give a record of common ancestry and often depicts the history of evolution.

Convergent Evolution

Convergent Evolution

Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.The structures that arise from convergent evolution are called analogous structures. They are similar in function even if they are dissimilar in structure. Further, structures can be analogous while also...

You might also read

Related Articles

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

Sort by

Same author

Complex foraging behaviours in wild birds emerge from social learning and recombination of components.

Philosophical transactions of the Royal Society of London. Series B, Biological sciences·2021

Same author

Diurnal variation in the production of vocal information about food supports a model of social adjustment in wild songbirds.

Proceedings. Biological sciences·2019

Same author

A high-density SNP chip for genotyping great tit (Parus major) populations and its application to studying the genetic architecture of exploration behaviour.

Molecular ecology resources·2018

Same author

Structure and stability of genetic variance-covariance matrices: A Bayesian sparse factor analysis of transcriptional variation in the three-spined stickleback.

Molecular ecology·2017

Same author

QUANTITATIVE GENETICS OF SEXUAL SIZE DIMORPHISM IN THE COLLARED FLYCATCHER, FICEDULA ALBICOLLIS.

Evolution; international journal of organic evolution·2017

Same author

Multivariate selection and intersexual genetic constraints in a wild bird population.

Journal of evolutionary biology·2016

Search research articles

Related Experiment Video

Updated: Jul 9, 2026

Who is Who? Non-invasive Methods to Individually Sex and Mark Altricial Chicks

Who is Who? Non-invasive Methods to Individually Sex and Mark Altricial Chicks

Published on: May 24, 2014

Cryptic evolution in a wild bird population.

J Merilä¹, L E Kruuk, B C Sheldon

¹Department of Population Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18d, SE-752 36 Uppsala, Sweden. juha.merila@ebc.uu.se

|July 14, 2001

Summary

Microevolutionary studies show that while traits like bird condition face consistent selection, environmental changes can mask genetic evolution. This cryptic evolution, where underlying genetic changes aren't reflected in population averages, may be widespread in nature.

More Related Videos

Probing the Limits of Egg Recognition Using Egg Rejection Experiments Along Phenotypic Gradients

Probing the Limits of Egg Recognition Using Egg Rejection Experiments Along Phenotypic Gradients

Published on: August 22, 2018

Visually Sexing Loggerhead Shrike (Lanius Ludovicianus) Using Plumage Coloration and Pattern

Visually Sexing Loggerhead Shrike (Lanius Ludovicianus) Using Plumage Coloration and Pattern

Published on: March 8, 2020

Related Experiment Videos

Last Updated: Jul 9, 2026

Who is Who? Non-invasive Methods to Individually Sex and Mark Altricial Chicks

Who is Who? Non-invasive Methods to Individually Sex and Mark Altricial Chicks

Published on: May 24, 2014

Probing the Limits of Egg Recognition Using Egg Rejection Experiments Along Phenotypic Gradients

Probing the Limits of Egg Recognition Using Egg Rejection Experiments Along Phenotypic Gradients

Published on: August 22, 2018

Visually Sexing Loggerhead Shrike (Lanius Ludovicianus) Using Plumage Coloration and Pattern

Visually Sexing Loggerhead Shrike (Lanius Ludovicianus) Using Plumage Coloration and Pattern

Published on: March 8, 2020

Area of Science:

Evolutionary biology
Population genetics
Animal behavior

Background:

Microevolution is predicted but rarely documented in wild populations.
Heritable traits under consistent selection often show no expected evolutionary response.
Environmental changes may mask genetic responses to selection.

Purpose of the Study:

To investigate microevolution in collared flycatchers (Ficedula albicollis).
To examine selection and evolution of relative body weight ('condition') over 20 years.
To test the hypothesis that environmental changes can conceal underlying evolution.

Main Methods:

Utilized a 20-year dataset of collared flycatchers.
Analyzed selection on phenotypic and additive genetic components of condition.
Employed an animal model to estimate breeding values.

Main Results:

Consistent positive directional selection was observed for condition.
The mean phenotypic value of condition declined over time.
The mean breeding value for condition increased over time, despite phenotypic decline.

Conclusions:

A mismatch exists between genetic evolution and phenotypic change in condition.
Environmental deterioration can mask underlying genetic evolution (cryptic evolution).
Cryptic evolution may be a common phenomenon in natural populations.