Close X
Thursday, November 14, 2024
ADVT 
Interesting

'Ancient fish pioneered penetrative sex'

Darpan News Desk IANS, 20 Oct, 2014 07:18 AM
    Sexual intercourse was pioneered by a group of unsightly, long-extinct fish about 385 million years ago in Scotland, Australian scientists have reported.
     
    After studying the fossils of these ancient fish called placoderms - armour-plated creatures, which gave rise to all current vertebrates with jaws - the researchers found that their descendants switched sexual practices from internal to external fertilisation, an event previously thought to be evolutionarily improbable.
     
    "This was totally unexpected. Biologists thought that there could not be a reversion back from internal fertilisation to external fertilisation. We have shown it must have happened this way," said John Long, palaeontologist at the Flinders University in Adelaide, Australia.
     
    Long's team studied placoderms and found structures in fossils that they interpret as bony 'claspers' - male organs that penetrate the female and deliver sperm.
     
    The researchers had previously shown that one placoderm species was the earliest animal known to have engaged in penetrative sex.
     
    But latest research reported by the journal Nature shows that an even earlier group of placoderms called antiarchs also used this method of fertilisation.
     
    "The finding is significant because antiarchs are considered the most basal (meaning those closest to the roots of the animal family tree) jawed vertebrates, and so it suggests that all placoderms reproduced through internal fertilization using claspers," Long added.
     
    But the implications of this finding are even more penetrating.
     
    According to Long, the oldest bony fishes which followed placoderms in the evolutionary tree show no evidence for internal fertilisation.
     
    "Thus, at some point, early fishes must have lost the internal fertilisation method seen in placoderms, before some of their descendants 're-invented' organs with a similar function - ranging from similar claspers in sharks and rays today to the penises of modern humans," the authors concluded.

    MORE Interesting ARTICLES

    Is that a 'traffic signal' on Mars?

    Is that a 'traffic signal' on Mars?
    Are aliens using traffic signal to cross roads on Red Planet? Fun apart, NASA's Curiosity Mars rover has clicked a picture on the Martian surface that resembles a “traffic signal”.

    Is that a 'traffic signal' on Mars?

    Men with bulging bellies last longer in bed

    Men with bulging bellies last longer in bed
    Do not be ashamed of your bulging belly any more during sex. A fascinating research shows that men with larger bellies perform much longer between the sheets...

    Men with bulging bellies last longer in bed

    Yoga and meditation help people use gadgets better

    Yoga and meditation help people use gadgets better
    In recent years, there has been a lot of attention on improving the computer side of the brain-computer interface but very little attention to the brain side....

    Yoga and meditation help people use gadgets better

    Saudi man divorces wife for not closing car door

    Saudi man divorces wife for not closing car door
    The couple reportedly went out on a picnic and when they returned home, the wife got out, helped their children to do so and then moved to go into the...

    Saudi man divorces wife for not closing car door

    Media multi-tasking could change brain structure

    Media multi-tasking could change brain structure
    Jumping from screen to screen - using mobile phones, laptops and other media devices simultaneously - could be changing the structure of your brain...

    Media multi-tasking could change brain structure

    Educated women less inclined to use dialectal words

    Educated women less inclined to use dialectal words
    Though the study focused on a group of speakers in a single Italian region, the modelling methods used could be applied to predict how geography and...

    Educated women less inclined to use dialectal words