Science Fiction
Dictionary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
 |
This Species Has Seven Sexes
The single-celled organism Tetrahymena thermophila has seven sexes, not just two, which you would think would improve your odds tremendously.
(Young healthy VII WLTM I, II, III, IV, V, VI for conjugation
Image: Volker Steger/E. Cole/SPL)
Tetrahymena thermophila is a single cell covered with a coat of hairs called cilia. The cilia wave back and forth, powering it through the water.Its seven sexes are rather prosaically named I, II, III, IV, V, VI and VII. An individual of a given sex can mate with individuals of any except its own, so there are 21 possible orientations.
In most animals, what sex you are is straightforward. A human with two X chromosomes is female, while someone with an X and a Y is male...
Not so for Tetrahymena. Its sex is controlled by a gene called mat, but it is not as simple as one version of the gene encoding one sex. Instead, each allele of the gene sets out a series of probabilities. For instance, an individual born with the mat2 allele has zero chance of being type I, a 0.15 chance of being type II, a 0.09 chance of being type II, and so on.
There are at least 14 of these alleles, each offering a different set of probabilities...
Although not a prediction, sf writers often explore unusual, well, circumstances. In his sardonic 1949 story Venus and the Seven Sexes, writer William Tenn tells us about a rather complicated arrangement - the seven sexes of the Plookh.
"...I am a representative of the seventh sex - nzred.""A nzred, huh? What do you do?"
"I coordinate... You see, a mlenb is primarily interested in winning the affections of a likely strob and finding a tkan whom he can love. A tkan merely courts a mlenb and is attracted to a good guur. I am responsible for getting a complete chain of these individuals in operation, a chain of compatibility where perfect amity runs in a complete circle - a chain which will produce offspring of maximum variability. Then, after the matrimonial convention, when the chain is established, each sex begins to secrete in its original germ with the full forty-nine chromosomes. A busy time for the nzredd!
"The nzred... fits himself in at any point in the chain which the exigencies of the situation seem to demand. He may receive the sextuple supergamete from the tkan and transmit the original single gamete to the guur, he may be between the flin and blap, the blap and srob, whatever is required."
Via NewScientist.
Scroll down for more stories in the same category. (Story submitted 3/16/2011)
Follow this kind of news @Technovelgy.| Email | RSS | Blog It | Stumble | del.icio.us | Digg | Reddit |
Would
you like to contribute a story tip?
It's easy:
Get the URL of the story, and the related sf author, and add
it here.
Comment/Join discussion ( 3 )
Related News Stories - (" Biology ")
Biological War: A Scenario
'And now they wre busily transforming all their companions, and so on, and so on...' - Greg Bear, 1984.
What'll You Have? Extinct Animals Returned, Or Synthetic Eggshells?
'...a new plastic with the characteristics of an avian eggshell.' - Michael Crichton, 1990.
Black Fungus Blocks Radiation
'You were surrounded by Astrophage most of the time' - Andy Weir, 2021.
Lunar Biorepository Proposed For Cryo-Preservation Of Earth Species
'...there was no one alive who had ever seen them. But they existed in the Life Bank.' - John Varley, 1977.
Technovelgy (that's tech-novel-gee!) is devoted to the creative science inventions and ideas of sf authors. Look for the Invention Category that interests you, the Glossary, the Invention Timeline, or see what's New.
Science Fiction
Timeline
1600-1899
1900-1939
1940's 1950's
1960's 1970's
1980's 1990's
2000's 2010's
Current News
Tactile Skin Supplier Map
'What strange sensitivity! What an amazing development of science was manifested in every move and act and word of this Robot!'
Flock Stymied By 'Adversarial Fashion'
'Forget the head atop it, the legs below, feet, arms, hands. It compels erasure.'
Orb Nomad Zero-Emission Electric Aircraft
'That explains how it was so easy for me to remain motionless in midair or to perch on a flagpole in imitation of a giant bird, even in the windy city of Chicago.'
ICE Buys Shock Gloves Like Batman's
What else is the Caped Crusader using?
Factories In The Sky Will Surpass Those Of Earth
'The thirty-odd miles of The Factory’s circumference...'
Sleeper Drones Lie in Wait
'Wandering mines, you took them out on the edge of the desert, set them down and activated them.'
Warfare Goes Underground In Ukraine
'Once in the very first weeks of the war, before everyone had been evacuated from the surface...'
3D Printed Organs From Space
'For a while your colonists will have to come up to the [orbital] Hospital...'
Robot Bees 3D Printed By Festo
'At first I was struck by the large size of these bees..'
DIY Robot Scorpion Crushes It
'...it raised its front end off the ground and waved its antennae at them, then raised one armoured claw as if to snip them out of the sky.'
How To Settle An Argument Between Two Robots
'Henry... assumed the curious absent look of a robot talking on the TBR circuits.'
The Wind Phone Calls Those Who Have Passed On
'Only I heard that!'
Don't Want To Wear A TIght Shiny Bodysuit?
'He looked a good bit like an elderly, fat beetle.'
Light Society: Simulates Earth-Scale Society With A Billion AI Agents
'The king, an old hand in the running of tyrannies, instantly grasped the directions...'
Satyress Centaur Robot Horror Reminds Everyone Of Something
'Fess was very dutiful'
When Colds Threaten You Can't Do This - Or Can You?
'...a hemispherical force field enclosing his head.'
