Steve Connor: Why sexual equality is nature's ideal

Science Notebook

Share
Related Topics

People often ask me if there is a biological reason for there being a roughly 50:50 ratio of males to females in the population. If one man can inseminate hundreds of women in his lifetime, surely there is no biological need for so many males to be born.

The question came up again the other day with a study showing that there was a very slight, but statistically significant, increase in the probability of a woman giving birth to a baby girl the nearer the mother lives to the equator, compared to mothers who live in more northerly or southerly latitudes.

The slight bias towards girls as you move to the equator may be a remnant trait of the seasonal nature of human reproduction when we lived a hunter-gatherer existence. In any case, the 50:50 ratio is still biased overall to males, with about 106 boys in the world being born for every 100 girls, because males are more likely to die in childhood.

But that still leaves the 50:50 question. The answer was in fact solved in the 1930s by the mathematical geneticist Ronald Aylmer Fisher. In essence, it's because in a population heavily weighted to females, it becomes an advantage for a mother to give birth to males, and vice versa if the population gets skewed towards males. In effect there is a perpetual balancing act in evolution that keeps the human sex ratio at about 50:50.

Milking a whale of a tale

A story popped up last week on the Planet Earth website of the Natural Environment Research Council about a nutritious alternative to cow's milk. Scientists at its Marine Research Institute in "Mid Glamorgan" devised a way to milk Minke whales, producing 40 times more milk than cows. They trained pods of the whales to be milked in a Norwegian fjord. It sounds implausible... because it is. Now 1 April is behind us, we can give a little sigh of relief for another year.

Riot of a man

While we are on the subject of April Fools' day, the anti-capitalist demonstration in London threw up an old face in the shape of Professor Chris Knight who has been suspended from his post at the University of East London for inciting people to eat bankers. I remember Chris from years ago when he came up with the "sex strike" theory for human menstruation. It's too complicated to be explained here but it involved stone age man (and woman), a full moon, red ochre, hunting meat and making whoopee.

React Now

Latest stories from i100
Have you tried new the Independent Digital Edition apps?
iJobs Job Widget
iJobs General

Marketing Manager - Leicestershire - £35,000

£30000 - £35000 per annum: Ashdown Group: Marketing Manager (CIM, B2B, MS Offi...

Marketing Executive (B2B and B2C) - Rugby, Warwickshire

£22000 - £25000 per annum: Ashdown Group: A highly successful organisation wit...

SEN Coordinator + Teacher (SENCO)

£1 per day: Randstad Education Leeds: Job Purpose To work closely with the he...

Research Manager - Quantitative/Qualitative

£32000 - £42000 Per Annum: Clearwater People Solutions Ltd: Our client is curr...

Day In a Page

Read Next
Piper Ryan Randall leads a pro-Scottish independence rally in the suburbs of Edinburgh  

i Editor's Letter: Britain survives, but change is afoot

Oliver Duff Oliver Duff
Some believe that David Cameron is to blame for allowing Alex Salmond a referendum  

Scottish referendum: So how about the English now being given a chance to split from England?

Mark Steel
Scottish referendum: The Yes vote was the love that dared speak its name, but it was not to be

Despite the result, this is the end of the status quo

Boyd Tonkin on the fall-out from the Scottish referendum
Manolo Blahnik: The high priest of heels talks flats, Englishness, and why he loves Mary Beard

Manolo Blahnik: Flats, Englishness, and Mary Beard

The shoe designer who has been dubbed 'the patron saint of the stiletto'
The Beatles biographer reveals exclusive original manuscripts of some of the best pop songs ever written

Scrambled eggs and LSD

Behind The Beatles' lyrics - thanks to Hunter Davis's original manuscript copies
'Normcore' fashion: Blending in is the new standing out in latest catwalk non-trend

'Normcore': Blending in is the new standing out

Just when fashion was in grave danger of running out of trends, it only went and invented the non-trend. Rebecca Gonsalves investigates
Dance’s new leading ladies fight back: How female vocalists are now writing their own hits

New leading ladies of dance fight back

How female vocalists are now writing their own hits
Mystery of the Ground Zero wedding photo

A shot in the dark

Mystery of the wedding photo from Ground Zero
His life, the universe and everything

His life, the universe and everything

New biography sheds light on comic genius of Douglas Adams
Save us from small screen superheroes

Save us from small screen superheroes

Shows like Agents of S.H.I.E.L.D are little more than marketing tools
Reach for the skies

Reach for the skies

From pools to football pitches, rooftop living is looking up
These are the 12 best hotel spas in the UK

12 best hotel spas in the UK

Some hotels go all out on facilities; others stand out for the sheer quality of treatments
These Iranian-controlled Shia militias used to specialise in killing American soldiers. Now they are fighting Isis, backed up by US airstrikes

Widespread fear of Isis is producing strange bedfellows

Iranian-controlled Shia militias that used to kill American soldiers are now fighting Isis, helped by US airstrikes
Topshop goes part Athena poster, part last spring Prada

Topshop goes part Athena poster, part last spring Prada

Shoppers don't come to Topshop for the unique
How to make a Lego masterpiece

How to make a Lego masterpiece

Toy breaks out of the nursery and heads for the gallery
Meet the ‘Endies’ – city dwellers who are too poor to have fun

Meet the ‘Endies’ – city dwellers who are too poor to have fun

Urbanites are cursed with an acronym pointing to Employed but No Disposable Income or Savings
Paisley’s decision to make peace with IRA enemies might remind the Arabs of Sadat

Ian Paisley’s decision to make peace with his IRA enemies

His Save Ulster from Sodomy campaign would surely have been supported by many a Sunni imam