Connect with us

Science & Technology

Dinosaurs struggled to survive for tens of millions of years before extinction event

Gorkha Post

Published

on

MIAMI — Dinosaurs struggled to survive for tens of millions of years before they finally went extinct, an event widely blamed on the environmental fallout from an asteroid strike, researchers say.

The argument offers the latest salvo in a long-running debate among scientists over the state of dinosaur health in their final years on Earth — some say they were flourishing, while others say they were strongly in decline.

For the study in the Proceedings of the National Academy of Sciences, researchers combed through fossil records from around the world and performed a statistical analysis showing that various species of dinosaurs were going extinct at a faster pace than new ones were emerging for a period of at least 40 million years prior to the cosmic debris that smashed into what is modern-day Mexico.

“We were not expecting this result,” lead author Manabu Sakamoto, a paleontologist at the University of Reading, said.

“While the asteroid impact is still the prime candidate for the dinosaurs’ final disappearance, it is clear that they were already past their prime in an evolutionary sense.”

For instance, long-necked vegetarian sauropod dinosaurs — the largest land animals known to exist — were in the fastest decline, the study found.

But the ropods, the group that includes the iconic, meat-eating Tyrannosaurus rex, were disappearing at a more gradual pace.

Factors in their struggle likely included the break-up of continental land masses and sustained volcanic activity, the study said.

Then, a giant asteroid collided with the Earth — known as the Chicxulub impact in Mexico — 66 million years ago, causing a massive dust storm that blocked the Sun and led to a period of global cooling and widespread plant deaths.

ALSO READ :  Google unveils medical wristband that tracks wellbeing

Without trees and vegetation, an important food and shelter source disappeared, and so did the dinosaurs.

“This suggests that for tens of millions of years before their ultimate demise, dinosaurs were beginning to lose their edge as the dominant species on Earth,” Dr Sakamoto said.

Even more, the research offers a look into the future. With many species already struggling due to human-driven climate change, those on the edge may be completely wiped out in the event of a disaster.

“Our study strongly indicates that if a group of animals is experiencing a fast pace of extinction more so than they can replace, then they are prone to annihilation once a major catastrophe occurs,” Dr Sakamoto said.

“This has huge implications for our current and future biodiversity, given the unprecedented speed at which species are going extinct owing to the ongoing human-caused climate change.”

AFP

Continue Reading

Science & Technology

Researchers successfully grow human cells in sheep embryos

Raghu Kshitiz

Published

on

Researchers successfully grow human cells in sheep embryos. Represenatational image

KATHMANDU — In an incredible development that could possibly go a long way in medical practices, scientists in California are working on a way to reduce organ transplants and rejections: Growing embryos in sheep and pigs containing human patients’ cells.

In a transplant breakthrough, scientists at the University of California said they have achieved sheep embryos in which around one in every 10,000 cells was human, according to UPI report.

The researchers presented preliminary findings Saturday at the American Association for the Advancement of Science’s annual meeting in Austin, Texas.

The new finding paves way for genetically tailoring the organs to be compatible with the immune system of the patient receiving them, thus removing the possibility of rejection, the report said.

ALSO READ :  Dinosaurs’ extinction not because of volcanoes, new study says

The hybrid embryos contain both human and sheep cells and were created in an early step toward growing human organs in farm animals before transplanting them into patients.

Last year, the same researchers introduced human stem cells into early pig embryos, producing embryos with about one in every 100,000 cells being human.

The experiment began with Hiro Nakauchi, from the University of Tokyo, who grew a mouse with a rat pancreas and a rat with a mouse pancreas.

When cells from the rat-grown mouse pancreas were transplanted into a diabetic mouse, they made enough insulin to cure the condition without being rejected.

Mice and rats are different types of rodents with the former having thin slightly hairy tails, while rats have thicker hairless scaly tails.

ALSO READ :  YouTube to expand teams reviewing extremist content

“The next step was to move into large animals,” Nakauchi said. Since this was prohibited in Japan, he moved to the Stanford University in the US.

Nakauchi’s rodent work has demonstrated that you can “grow organs in a different species and cure a disease without [suppressing the immune system],” added co-researcher Pablo Ross, Professor at from the University of California, Davis.

“We are working together to translate the technology into humans, to solve the terrible shortage of organs for transplantation. In the US, 20 people die every day because they cannot get the organs they need,” Ross explained.

With Agency Inputs

Continue Reading
Advertisement Cheap Air fare and package tours!

LATEST TWEET

Classifieds

Posted 2 months ago

We have latest collections of designer sarees. Contact for wholesale or retails prices. We also deliver all types of fashion collections for men and women.

 Fashion & Clothings /  Kathmandu / 87 views

NPR 2,999.00

Posted 2 months ago

Remember us for all travel related services : Hotel booking ( Globally) Vehicle reservation Flight Ticket( Domestic/International) Tour packages Train ticket reservation Hiking and Trekking

 Travel & Tours /  Kathmandu / 82 views

NPR 2,000.00

Search Listings

TOP PICKS