Who's a pretty boy den? |
Sexual selection: now there's a thing. Most higher
animals and some lower animals too (definition Flaxen?) are subject to this
phenomenon. Simply put, it involves mate selection and preference for
reproduction. Almost exclusively this is practised by the female of the
species. This makes good biological and evolutionary sense as the female is
responsible for harbouring the foetus within her body, supplying nutrients and
in many cases continuing to nurture the offspring after they are born. In
species where the male's only contribution to the effort is supplying the seed
of life, it behoves the female to be picky. Therefore, the female will choose a
mate she considers genetically 'fit'. This does not occur at the conscious
level but is ingrained within. She is apt to pick the healthy and strongest of
males as a visible demonstration of good genes. Even where the domestic
arrangement favours male involvement in bringing up the brood, it still makes
good sense for the female to pick a good healthy mate. In some species,
especially mammalian species, the males contend amongst themselves for sexual
access to the females. This often takes the form of violence and the winner, if
he is able, will gain a harem. This is a very brutal but effective way to
demonstrate your fitness and ability to sire strong healthy brats which in
their turn will be able to pass on their genes to the next generation. In other
species, the selection process can seem bizarre resulting in some strange male
attributes, well at least to the untrained eye.
Consider the humble peacock. The female is the
dowdiest of birds. The male, in contrast, is bedecked and bejewelled with a
plumage reminiscent of a rich scintillating tapestry. It appears that the
female has a preference for males with the most ornate feather arrangements.
This may seem frivolous and even dangerous for the male as a great deal of
energy investment is necessary to maintain an elaborate display. Furthermore,
the heavy gaudy feathers make escape difficult and detection by predators easy.
However, biology is never frivolous, or more importantly, evolution is never
flippant with the bestowal of her gifts. An ostentatious male signals his
health and fitness by his display. In other words, the magnificent plumage is a
marker for more important traits controlled by underlying genetic factors.
Sex amongst animals is not always consensual. Bird
species, in particular, may engage in rape in order to sow their seed into the
next generation. How is the prudent female able to cope under such
circumstances? It benefits her not at all if her children are fathered by a
relatively weak, and soon to be eaten, male. But the wily female has a highly
sophisticated adaptive solution......
Consider the very unassuming, duck. Female ducks
have evolved a rather ingenious reproductive system. The vagina is a
labyrinth, with twists and turns ending in semen traps. There is only one true
path to the promised land and this guarded by a muscular spasm. The drake is
generally not a sensitive lover and will engage in rape and often gang rape. By
constricting her vaginal muscles the female is able to guide the drake’s penis
and hence the semen to a place not conducive to conception. Thus the female can
exert control over who father’s her ducklings. The highly motivated males also
come under the influence of evolutionary adaptation. In turn, they have evolved
a rather large penis with a distinctive corkscrew appearance. Hence the male is
able to better navigate the contortions and convolutions of the female’s vaginal
anatomy. Selection for a specialised vagina has acted as a spur for the
evolution of countermeasures. The advantage, however,
is with the female as they are able to influence conception in 93% of
cases. Only 3% of avian species are endowed with a penis. Therefore drakes are
extremely privileged in this regard. Although on the flip side they have to
suffer the indignity of the organ sloughing off once a year. But despair not
gentle reader, and do not pity the penisless (not a real word) male, for he has
the ability to grow another just in time for the next raping/mating
season.
Who's a big boy den?
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'Tis indeed a good job that the peacock approach never caught on amongst primates: imagine the howls of anguish from those delectable young ladies who had coquettishly set their hat at Liberace, Elton John, Boy George &c.
ReplyDeleteWasn't Elton Bog married at some point?
DeleteStill is:- except first time was to a Kraut woman, second time to a Canadian bloke.
DeleteMust be a few Saturday night renderings of The Lumberjack Song chez Elton.
I seem to recall something about baboons.... However, If this link works.. https://books.google.co.uk/books?id=U8AFxmc76rcC&pg=PA136&lpg=PA136&dq=guppies+camouflage&source=bl&ots=nCm_BKud3l&sig=pv6VPIj6gmLY_C0yjeUS-Wgk4zc&hl=en&sa=X&ved=0ahUKEwjsxP-a6trZAhXMY8AKHTpsCK4Q6AEIRzAG#v=onepage&q=guppies%20camouflage&f=false
ReplyDeleteHopefully you will find a fascinating tale of the breeding habits of guppies. And how the females select their partners..
The link worked fine. An interesting interplay between sexual selection and predation pressure. Another fine tome by the good Professor.
Delete