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 ")

Baubotanik - Construction Botany - Builds Bridges
'A dwelling must be all of a unit—the walls, the drainage, the decor grown in!' - Jack Vance, 1954.

Mice Gestate In Mechanical Womb
'... in the Decanting Room, the newly-unbottled babes uttered their first yell of horror and amazement.' - Aldous Huxley, 1932.

Worlds With Underground Oceans More Conducive To Life
'There is life on Europa.' - Arthur C. Clarke, 1982.

Monkey Gets A Bigger Brain, Thanks To Human Gene
'It's a madhouse! a madhouse!' - Planet of the Apes, 1968.

 

Google
  Web TechNovelgy.com   

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

Jetson ONE Personal Electric Aerial Vehicle
Who says you can't have your flying car?

Starlab By Nanoracks, A Commercial Space Station
'Webb Foster had built his space laboratory... It was a great crystal sphere, a thousand feet in diameter.'

Auto-Targeting Fire Sprinkler Systems Now Reality
I think every kitchen should have one of these.

Monarch Tractor - It's Electric, Autonomous and Smart
'Driver-optional' and follows gestures.

'Seabreeze' Apple And UCLA Project To Beat Depression
'It's illegal to hold back information during a psyche test,' the machine said peevishly.'

Hovermap By Emesent Autonomous Mapping Works Indoors - and Out
Perfect for exploring ancient artifacts on distant planets.

Sono Motor's Sion Sun-Powered Car
'...six square yards of sunpower screens on its low curved roof.'

LEONARDO Robot Has Legs And Thrusters, Can Skateboard, Slackline
'a walking balloon proceeded with long strides of its aluminum legs over a slant of steep upland.'

Xavier Robots On Patrol For 'Anti-Social Behavior'
'This was as close as a robot could get to a cop in uniform.'

Rotating House in Bosnia
'... feel free to turn the house on your own.'

Ingenious Engineer Creates DIY Feeding Robot
'Waldo flexed and extended his fingers gently; the two pairs of waldoes in the screen followed in exact, simultaneous parallelism.'

SpaceX Creates 'Tholian Web' Mega Constellation Of Satellites
'We shall not see home again!'

Do Smart Glasses Need Forward-Facing Cameras?
'They were stylish, with yellow-tinted lenses and hip frames, but the posts were unusually thick.'

Adorable One-Seater Electric Car From Wuxi Sinotech
'Noiselessly, on rubber-tired wheels, they journeyed...'

Zoom Adds Real-Time, Live Translation
'He immediately turned the small shining disc of the Language Rectifier..'

It's Spacewalk Sunday, Thanks To The ESA
'The delicious, indescribable pleasure of being a little planet swinging through space...'

More SF in the News Stories

More Beyond Technovelgy science news stories

Home | Glossary | Invention Timeline | Category | New | Contact Us | FAQ | Advertise |
Technovelgy.com - where science meets fiction™

Copyright© Technovelgy LLC; all rights reserved.