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

Recruitment Genius: Online Media Sales Trainee

£15000 - £30000 per annum: Recruitment Genius: Now our rapidly expanding and A...

Recruitment Genius: Public House Manager / Management Couples

£15000 - £20000 per annum: Recruitment Genius: Are you passionate about great ...

Recruitment Genius: Production Planner

£20000 - £30000 per annum: Recruitment Genius: This fast growing reinforcing s...

Recruitment Genius: General Factory Operatives

£18000 - £35000 per annum: Recruitment Genius: This fast growing reinforcing s...

Day In a Page

Read Next
 

If I were Prime Minister: Every privatised corner of the NHS would be taken back into public ownership

Philip Pullman
 

Errors & Omissions: Magna Carta, sexing bishops and ministerial aides

John Rentoul
Isis hostage crisis: The prisoner swap has only one purpose for the militants - recognition its Islamic State exists and that foreign nations acknowledge its power

Isis hostage crisis

The prisoner swap has only one purpose for the militants - recognition its Islamic State exists and that foreign nations acknowledge its power, says Robert Fisk
Missing salvage expert who found $50m of sunken treasure before disappearing, tracked down at last

The runaway buccaneers and the ship full of gold

Salvage expert Tommy Thompson found sunken treasure worth millions. Then he vanished... until now
Homeless Veterans appeal: ‘If you’re hard on the world you are hard on yourself’

Homeless Veterans appeal: ‘If you’re hard on the world you are hard on yourself’

Maverick artist Grayson Perry backs our campaign
Assisted Dying Bill: I want to be able to decide about my own death - I want to have control of my life

Assisted Dying Bill: 'I want control of my life'

This week the Assisted Dying Bill is debated in the Lords. Virginia Ironside, who has already made plans for her own self-deliverance, argues that it's time we allowed people a humane, compassionate death
Move over, kale - cabbage is the new rising star

Cabbage is king again

Sophie Morris banishes thoughts of soggy school dinners and turns over a new leaf
11 best winter skin treats

Give your moisturiser a helping hand: 11 best winter skin treats

Get an extra boost of nourishment from one of these hard-working products
Paul Scholes column: The more Jose Mourinho attempts to influence match officials, the more they are likely to ignore him

Paul Scholes column

The more Jose Mourinho attempts to influence match officials, the more they are likely to ignore him
Frank Warren column: No cigar, but pots of money: here come the Cubans

Frank Warren's Ringside

No cigar, but pots of money: here come the Cubans
Isis hostage crisis: Militant group stands strong as its numerous enemies fail to find a common plan to defeat it

Isis stands strong as its numerous enemies fail to find a common plan to defeat it

The jihadis are being squeezed militarily and economically, but there is no sign of an implosion, says Patrick Cockburn
Virtual reality thrusts viewers into the frontline of global events - and puts film-goers at the heart of the action

Virtual reality: Seeing is believing

Virtual reality thrusts viewers into the frontline of global events - and puts film-goers at the heart of the action
Homeless Veterans appeal: MP says Coalition ‘not doing enough’

Homeless Veterans appeal

MP says Coalition ‘not doing enough’ to help
Larry David, Steve Coogan and other comedians share stories of depression in new documentary

Comedians share stories of depression

The director of the new documentary, Kevin Pollak, tells Jessica Barrett how he got them to talk
Has The Archers lost the plot with it's spicy storylines?

Has The Archers lost the plot?

A growing number of listeners are voicing their discontent over the rural soap's spicy storylines; so loudly that even the BBC's director-general seems worried, says Simon Kelner
English Heritage adds 14 post-war office buildings to its protected lists

14 office buildings added to protected lists

Christopher Beanland explores the underrated appeal of these palaces of pen-pushing
Human skull discovery in Israel proves humans lived side-by-side with Neanderthals

Human skull discovery in Israel proves humans lived side-by-side with Neanderthals

Scientists unearthed the cranial fragments from Manot Cave in West Galilee