Scientists believe they have cracked evolution's biggest mystery... what came first the chicken or the egg!

14 June 2023, 15:59 | Updated: 14 June 2023, 17:06

What came first...the chicken or the egg
What came first...the chicken or the egg. Picture: Alamy

By StephenRigley

Scientists say they've finally solved the most baffling of evolutionary conundrums - was it the chicken or the egg that came first.

Generations of scholars to schoolchildren have been stumped by the chicken-and-egg question but now researchers have discovered early ancestors of modern birds and reptiles may have given birth to live young.

In evolutionary terms, eggs were being laid by the chicken's distant dinosaur ancestors millions of years before the first chickens evolved.

But a research project has now found that the chicken's earliest reptilian ancestors, dating back millions of years before the dinosaurs evolved, may not have laid eggs as previously thought.

University of Bristol's School of Earth Sciences led the study, which saw 51 fossil species and 29 living species categorised as oviparous - laying hard or soft-shelled eggs - or viviparous - giving birth to live young - examined.

Experts there and at Nanjing University say that although the hard-shelled egg has often been seen as one of the greatest innovations in evolution, this research implies extended embryo retention - when the young are retained by the mother for a varying amount of time - actually gave this particular group of animals the ultimate protection.

Professor Michael Benton, from the University of Bristol, said: "Before the amniotes, the first tetrapods to evolve limbs from fishy fins were broadly amphibious in habits."They had to live in or near water to feed and breed, as in modern amphibians such as frogs and salamanders.

"When the amniotes came on the scene 320million years ago, they were able to break away from the water by evolving waterproof skin and other ways to control water loss.

"But the amniotic egg was the key.

"It was said to be a 'private pond' in which the developing reptile was protected from drying out in the warm climates and enabled the Amniota to move away from the waterside and dominate terrestrial ecosystems."

He added: "Our work, and that of many others in recent years, has consigned the classic 'reptile egg' model of the textbooks to the wastebasket."

Listen and subscribe to Guto Harri's Unprecedented: Inside Downing Street on Global Player

What came first...the chicken or the egg?
What came first...the chicken or the egg? Picture: Alamy

Read More: First photo emerges of Nottingham killings suspect as he 'tries to break into homeless hostel'

Read More: Third victim of Nottingham attack named as school caretaker as devastated son says 'I'm broken'

Project leader Professor Baoyu Jiang added: "This standard view has been challenged.

"Biologists had noticed many lizards and snakes display flexible reproductive strategy across oviparity and viviparity.

"Sometimes, closely related species show both behaviours, and it turns out that live-bearing lizards can flip back to laying eggs much more easily than had been assumed."

The study is published in Nature Ecology & Evolution.

More Latest News

See more More Latest News

Near-Earth asteroid, artwork

NASA gives major update on massive 'city killer' asteroid 'the size of Big Ben' striking earth and it's good news

Breaking
Breaking News

Man, 19, admits murdering his mother, sister and brother in Luton flat

Ozempic and Wegovy, injectable prescription weight loss medicines.

Fresh concerns over weight-loss jabs as medication linked to dozens of deaths

Conservative leader Kemi Badenoch has called for an investigation into the BBC Gaza documentary.

Kemi Badenoch calls for investigation into BBC Gaza documentary featuring grandson of Hamas founder

Chants of “f*** the feds” could be heard as the boys took control of the emergency vehicle.

GenZ mob run riot for TikTok stunt and swarm police cars during ‘free pop-up’ by streetwear clothing brands

Queen Elizabeth's Grammar School in Ashbourne, Derbyshire,

Boy, 15, arrested after school forced into lockdown after student 'behaving aggressively and threatening staff'

The Runcorn and Helsby MP has been sitting as an independent since he was suspended following his arrest in October

MP Mike Amesbury jailed for 10 weeks for punching man in street in 'unprovoked drunken' assault

Speaking via video link to a Kyiv conference, the Prime Minister reaffirmed that Britain is ready to commit British troops on the ground in Ukraine in order to maintain peace.

'Russia doesn't hold all the cards', Starmer says, as he tells Ukraine 'we are with you' three years on from invasion

Leanne Lucas has described for the first time the desperate moments when she helped children run to safety

'If I didn't get out, everyone was going to die': Hero yoga teacher tells how she saved children from Southport attacker

Moise Kean was carried into an ambulance after collapsing during Fiorentina’s game against Verona

Moise Kean update after ex-Everton star rushed to hospital after collapsing on the pitch

Demi Moore, winner of Outstanding Performance by a Female Actor in a Leading Role for 'The Substance,' appears backstage during the 31st annual SAG Awards

Demi Moore, Timothee Chalamet and Conclave cast big winners at the Screen Actors Guild

The former Prime Minister was speaking from Ukraine

Blaming Ukraine for Russian invasion is like accusing swimmers of attacking the shark in Jaws, Boris Johnson tells LBC

Dave Grohl playing a show in New York earlier this month

Mother of Dave Grohl’s love child revealed to be rock ’n’ roll fan 18 years his junior  - after months of secrecy

Pope Francis seen in January

Pope Francis is 'in critical condition with kidney failure' as he continues to battle pneumonia, Vatican says

x

Damp start to the week as winter washout brings further flood warnings to parts of the UK

Cyclists training in Regent's Park

Regent's Park cyclists plagued by violent 'bikejacking' gangs - as police 'say they won't patrol before 8am'