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

Natural Selection and Mating Preferences

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...

Mate Choice

Mate Choice

Mate choice—the decision about whom to mate with—is a type of natural selection, since animals must reproduce to pass down their genes. Mate choice is also called intersexual selection because the behavior occurs between the sexes.

Spermatogenesis

Spermatogenesis

Spermatogenesis is the process by which haploid sperm cells are produced in the male testes. It starts with stem cells located close to the outer rim of seminiferous tubules. These spermatogonial stem cells divide asymmetrically to give rise to additional stem cells (meaning that these structures “self-renew”), as well as sperm progenitors, called spermatocytes. Importantly, this method of asymmetric mitotic division maintains a population of spermatogonial stem cells in the male reproductive...

Spermatogenesis

Spermatogenesis

Spermatogenesis is a complex process that involves the development of sperm cells from undifferentiated stem cells in the seminiferous tubules of the testes. The process is essential for the production of mature and functional sperm cells that are capable of fertilizing an egg.
The process of spermatogenesis can be divided into mitosis, meiosis, and spermiogenesis. During mitosis, the spermatogonia or stem cells divide to produce two identical daughter cells, type A and B spermatogonia. Type-A...

Fertilization

Fertilization

During fertilization, an egg and sperm cell fuse to create a new diploid structure. In humans, the process occurs once the egg has been released from the ovary, and travels into the fallopian tubes. The process requires several key steps: 1) sperm present in the genital tract must locate the egg; 2) once there, sperm need to release enzymes to help them burrow through the protective zona pellucida of the egg; and 3) the membranes of a single sperm cell and egg must fuse, with the sperm...

Sperm Structure and Semen Composition

Sperm Structure and Semen Composition

During ejaculation, males release around 2-5 milliliters of semen, which is a complex mixture of mature sperm and various fluids produced by accessory glands. The mature sperm cells measure approximately 60 micrometers in length and consist of a head, neck, midpiece, and tail. The head is flattened and tapered, measuring about 4 to 5 micrometers in length. It contains a nucleus with condensed chromosomes and an acrosome, a cap-like structure filled with enzymes essential for penetrating the...

You might also read

Related Articles

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

Sort by

Same author

Solvent extraction of iodine species: mechanisms, technologies, and applications.

Analytical sciences : the international journal of the Japan Society for Analytical Chemistry·2026

Same author

Protist-dominated hard substrate faunas thrive at the deepest ocean depths.

Science (New York, N.Y.)·2026

Same author

Selective Iodide Recovery from Saline Water Using Electrodeposited Layered Organo-MnO<sub>2</sub>: Elucidation of the Sorption Mechanism.

Langmuir : the ACS journal of surfaces and colloids·2025

Same author

Revisiting the genus Bolbosoma Porta, 1908 (Acanthocephala: Polymorphidae): host specificity, phylogeny, and species synonymization.

Parasites & vectors·2025

Same author

Feasibility of interrupting the transmission of soil-transmitted helminths: the DeWorm3 community cluster-randomised controlled trial in Benin, India, and Malawi.

Lancet (London, England)·2025

Same author

Therapeutic Potential of Local Application of Fibroblast Growth Factor-2 to Periodontal Defects in a Preclinical Osteoporosis Model.

Bioengineering (Basel, Switzerland)·2025

Search research articles

Related Experiment Video

Updated: Jun 5, 2026

Assessing Differences in Sperm Competitive Ability in Drosophila

Assessing Differences in Sperm Competitive Ability in Drosophila

Published on: August 22, 2013

Mating behavior and the evolution of sperm design.

Lukas Schärer¹, D Timothy J Littlewood, Andrea Waeschenbach

¹Evolutionary Biology, Zoological Institute, University of Basel, 4051 Basel, Switzerland. lukas.scharer@unibas.ch

Proceedings of the National Academy of Sciences of the United States of America

|January 12, 2011

Summary

Sperm design complexity in Macrostomum flatworms is linked to mating behavior. Reciprocal mating favors complex sperm, while hypodermic insemination leads to simpler sperm and genital structures.

More Related Videos

Measuring Sperm Guidance and Motility within the Caenorhabditis elegans Hermaphrodite Reproductive Tract

Measuring Sperm Guidance and Motility within the Caenorhabditis elegans Hermaphrodite Reproductive Tract

Published on: June 6, 2019

Effect of Male Accessory Gland Products on Egg Laying in Gastropod Molluscs

Effect of Male Accessory Gland Products on Egg Laying in Gastropod Molluscs

Published on: June 22, 2014

Related Experiment Videos

Last Updated: Jun 5, 2026

Assessing Differences in Sperm Competitive Ability in Drosophila

Assessing Differences in Sperm Competitive Ability in Drosophila

Published on: August 22, 2013

Measuring Sperm Guidance and Motility within the Caenorhabditis elegans Hermaphrodite Reproductive Tract

Measuring Sperm Guidance and Motility within the Caenorhabditis elegans Hermaphrodite Reproductive Tract

Published on: June 6, 2019

Effect of Male Accessory Gland Products on Egg Laying in Gastropod Molluscs

Effect of Male Accessory Gland Products on Egg Laying in Gastropod Molluscs

Published on: June 22, 2014

Area of Science:

Evolutionary biology
Reproductive biology
Animal behavior

Background:

Sperm diversity is extensive and thought to be driven by variable fertilization conditions and sexual selection.
Sexual conflict and rapid evolution of mating conditions can influence sperm design.
Functional understanding of sperm diversity, especially in internally fertilizing species, remains limited.

Purpose of the Study:

To investigate the relationship between mating behavior and sperm design complexity in the flatworm genus Macrostomum.
To understand how changes in insemination method (reciprocal vs. hypodermic) affect sperm and genital morphology evolution.

Main Methods:

Phylogenetic comparative analyses were conducted across 16 species of Macrostomum.
Sperm morphology, mating behavior (reciprocal mating, hypodermic insemination), and genital morphology were examined.

Main Results:

Complex sperm design, including lateral bristles, is associated with reciprocal mating.
Hypodermic insemination evolved secondarily, leading to a loss of sperm complexity.
Hypodermic insemination is linked to the evolution of a needle-like copulatory organ, simpler sperm, and simpler female genital morphology.
Female postcopulatory sucking behavior and a thickened sperm-receiving organ epithelium appear to be female resistance traits.

Conclusions:

Mating system shifts, such as the evolution of hypodermic insemination, can fundamentally alter sperm competition dynamics.
This can drive drastic changes in sperm design and associated genital coevolution.
Interactions between sperm donor, sperm, and recipient are crucial in shaping reproductive trait evolution.