Navigation Links
Why don't more animals change their sex?
Date:2/3/2009

New Haven, Conn. Most animals, like humans, have separate sexes they are born, live out their lives and reproduce as one sex or the other. However, some animals live as one sex in part of their lifetime and then switch to the other sex, a phenomenon called sequential hermaphroditism. What remains a puzzle, according to Yale scientists, is why the phenomenon is so rare, since their analysis shows the biological "costs" of changing sexes rarely outweigh the advantages.

A report by Yale scientists in the March issue of The American Naturalist says that while this process is evolutionarily favored, its rarity cannot be explained by an analysis of the biological costs vs benefits.

Sequential hermaphroditism naturally occurs in various organisms from plants to fishes. Following four decades of research that established why sex change is advantageous, the question remained why it is rare among animals. In this study, Yale graduate student Erem Kazancıoğlu and his advisor Suzanne Alonzo, assistant professor of ecology and evolutionary biology, demonstrate that sex change is surprisingly robust against costs.

While the adaptive advantage of sex change is well understood, it is not clear why relatively few animals change sex. According to Alonzo, "An intuitive, yet rarely studied, explanation is that the considerable time or energy it takes to change sex make hermaphroditism unfeasible for most animals."

To test whether the biological costs of changing sex affect sex change actually occurs, the researchers built theoretical models of the hermaphrodite and separate-sex life histories. In their "game" models, sex change "players" vary the age of their sex change, while the separate-sex strategy responds by altering the number of male and female offspring it produces.

"We were surprised to see that a hermaphrodite could spend 30 percent of its lifetime in the process of change sex, and still persist in a population," said Kazancıoğlu. "This suggests that only huge costs can disfavor sex change."

So, why is sex change so rare? And, why does one species of fish reproduce strictly as separate sexes, while another very closely related species flexibly changes sex? A comparative study of hermaphroditic and separate-sex mating systems, which the authors are currently performing, may provide a clue, according to Kazancıoğlu, "Reproductive behaviors such as parental care seem to disfavor sex change in some species. We are investigating whether general patterns like these may explain the rarity of hermaphroditism."


'/>"/>

Contact: Janet Rettig Emanuel
janet.emanuel@yale.edu
203-432-2157
Yale University
Source:Eurekalert  

Related biology news :

1. Report: African, Asian, Latin American farm animals face extinction
2. UT researcher sheds new light on hybrid animals
3. Penn Veterinary Medicine report new strategy to create genetically-modified animals
4. UT researcher sheds new light on hybrid animals
5. Fungus genome yielding answers to protect grains, people and animals
6. From GM farm animals to embryonic stem cell research
7. Colorful view for first land animals
8. Gene guards grain-producing grasses so people and animals can eat
9. Texas A&M testing oral contraceptives for animals
10. Mantis shrimp vision reveals new way that animals can see
11. Common aquatic animals show extreme resistance to radiation
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Why don't more animals change their sex?
(Date:7/20/2017)... 20, 2017 Delta (NYSE: DAL ) customers now ... aircraft at Reagan Washington National Airport (DCA). ... Delta launches biometrics to board aircraft at ... Delta,s biometric boarding pass experience ... is now integrated into the boarding process to allow eligible Delta SkyMiles ...
(Date:6/14/2017)...  IBM (NYSE: IBM ) is introducing several innovative ... to developing collaboration between startups and global businesses, taking place ... the event, nine startups will showcase the solutions they have ... France is one ... a 30 percent increase in the number of startups created ...
(Date:5/16/2017)... DALLAS , May 16, 2017   ... for health organizations, and MD EMR Systems ... certified development partner for GE, have established a ... Patient Portal product and the GE Centricity™ products, ... Centricity EMR. These new integrations ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... , ... October 11, 2017 , ... ... (FDA) has granted orphan drug designation to SBT-100, its novel anti-STAT3 (Signal Transducer ... treatment of osteosarcoma. SBT-100 is able to cross the cell membrane and bind ...
(Date:10/10/2017)... Angeles, CA (PRWEB) , ... ... ... Inc., a development-stage cancer-focused pharmaceutical company advancing targeted antibody-drug conjugate (ADC) therapeutics, ... uses of targeted HPLN (Hybrid Polymerized Liposomal Nanoparticle), a technology developed in ...
(Date:10/10/2017)... ... October 10, 2017 , ... Dr. Bob Harman, founder ... local San Diego Rotary Club. The event entitled “Stem Cells and ... had 300+ attendees. Dr. Harman, DVM, MPVM was joined by two human doctors: ...
(Date:10/10/2017)... 2017 SomaGenics announced the receipt of a ... RealSeq®-SC (Single Cell), expected to be the first commercially ... microRNAs) from single cells using NGS methods. The NIH,s ... accelerate development of approaches to analyze the heterogeneity of ... techniques for measuring levels of mRNAs in individual cells ...
Breaking Biology Technology: