Close X
Monday, November 11, 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

    Cigarette ash can remove arsenic from water

    Cigarette ash can remove arsenic from water
    While the technology for removing arsenic from water exists and is in widespread use in industrialised areas, it is expensive and impractical for rural and developing regions....

    Cigarette ash can remove arsenic from water

    How consumers respond to guilt and shame

    How consumers respond to guilt and shame
    Consumers racked with guilt and shame tend to focus on concrete details of a product at the expense of the bigger picture, says a study co-authored by an Indian-origin researcher....

    How consumers respond to guilt and shame

    Can your dog win your true love?

    Can your dog win your true love?
    You may take your dog for morning walks or to a vet when it feels sick but your canine may not get the kind of love you shower on your kid, found a small yet significant study....

    Can your dog win your true love?

    Even fruit flies can help spot bombs and drugs

    Even fruit flies can help spot bombs and drugs
    The "nose" of fruit flies can identify odours emanating from illicit drugs and explosive substances almost as accurately as wine odour, says a study....

    Even fruit flies can help spot bombs and drugs

    Teens from rich nations better realise their science dream

    Teens from rich nations better realise their science dream
    Children interested in science are able to turn their interest into actual scientific knowledge to a greater extent when raised in wealthy countries, a study has found....

    Teens from rich nations better realise their science dream

    Yale researchers lay down strategies to reduce porn use

    Yale researchers lay down strategies to reduce porn use
    The study used an online questionnaire to garner information from 1,298 male pornography users. The goal was to see what happens when pornography....

    Yale researchers lay down strategies to reduce porn use