Heart of our evolution discovered: 380-million-year-old heart



A 380-million-year-old heart, the oldest ever found, coupled with a separate fossilized stomach, intestine, and liver were found in an ancient jawed fish, providing new insight into how our own bodies have changed through time.

The newly discovered anatomy of arthrodires, a class of extinct armored fishes that flourished between 419.2 million years ago and 358.9 million years ago, is similar to that of modern sharks, according to new research that was just published in Science. This discovery provides crucial new evolutionary clues.

Given the rarity of finding 3D preservation of soft tissues from ancient animals, lead researcher John Curtin Distinguished Professor Kate Trinajstic of Curtin's School of Molecular and Life Sciences and the Western Australian Museum said the discovery was exceptional.

As a palaeontologist with more than 20 years of experience studying fossils, Professor Trinajstic stated, "I was absolutely shocked to see a 3D and wonderfully preserved heart in a 380-million-year-old ancestor."

"These prehistoric fossils indicate there may have been a greater evolutionary jump between jawed and jawless vertebrates than is typically believed to have occurred. Like modern sharks, these fish physically have their hearts in their jaws and under their gills."

The intricate s-shaped heart in the arthrodire, which has two chambers with the smaller chamber sitting on top, is modeled in 3D for the first time in this study.

These traits, according to Professor Trinajstic, were advanced in such primitive animals, providing a rare glimpse into how the head and neck region started to evolve to make room for jaws, a crucial stage in the evolution of our own bodies.

Professor Trinajstic remarked, "For the first time, we can examine all the organs in a simple jawed fish, and we were very surprised to realize that they were not too different from ourselves.

"There was one important distinction, though: the fish had a huge liver that allowed it to stay buoyant, much like modern sharks do. We found no evidence of lungs in any of the extinct armoured fishes we examined, which shows that they developed independently in the bony fishes at a later time. Some modern bony fish, including lungfish and birchers, have lungs that evolved from swim bladders."

The fossils were found in Western Australia's Kimberley region in the Gogo Formation, which was formerly a sizable reef.

The specimens were scanned using neutron beams and synchrotron x-rays while still embedded in the limestone concretions with the assistance of scientists from the Australian Nuclear Science and Technology Organisation in Sydney and the European Synchrotron Radiation Facility in France. Based on the various mineral densities deposited by the bacteria and the surrounding rock matrix, the researchers constructed three-dimensional images of the soft tissues inside the specimens.

The Gogo arthrodires are now the most thoroughly understood of all jawed stem vertebrates, and this latest discovery of mineralized organs, along with earlier discoveries of muscles and embryos, clarifies an evolutionary transition on the line to living jawed vertebrates, including mammals and humans.

Professor John Long, a co-author from Flinders University, stated: "Because these fossils are without a doubt the best preserved in the world for this period, the recent discovery of soft organs in these extinct fish are undoubtedly the stuff of palaeontologists' dreams. They demonstrate the importance of the Gogo fossils in understanding the key moments in our long evolutionary history. Gogo is currently one of the most important fossil sites in the world. It has given us world firsts in everything from the origins of sex to the oldest vertebrate heart. It's time the location was given serious thought as a potential World Heritage Site."

Uppsala University co-author Professor Per Ahlberg said: "The Gogo fishes are truly unique in that their soft tissues have been preserved in three dimensions. In flattened fossils, where the soft anatomy is merely a stain on the rock, soft-tissue preservation is most frequently observed. Furthermore, we are extremely fortunate to be able to investigate these delicate soft tissues without harming them thanks to contemporary scanning technology. The project would have been unfeasible a few decades ago."

Working together on the Curtin-led study were Flinders University, the Western Australian Museum, the South Australian Museum, the Australian Nuclear Science and Technology Organization's nuclear reactor, the European Synchrotron Radiation Facility in France, Uppsala University, and the Australian Regenerative Medicine Institute at Monash University.

Curtin University

Comments

Post a Comment

Popular posts from this blog

Do You Sleep on Your Back or Side? Here's The Research on 'Optimal' Sleep Positions

Image
William Dement, a renowned sleep researcher at Stanford University, is quoted as saying that after 50 years of study, the only reason he can think of for why we sleep is "because we become sleepy." Sleep certainly matters for our health and wellbeing even though it may be, as one researcher put it, "the sole major habit in quest of a function." Do we, however, have it right? What do studies on sleeping positions say? Is there a proper sleeping position? The majority of people favor sleeping on their side. This is encouraging news because people who sleep on their backs are more likely to have trouble falling asleep or breathing during the night. Most of the time, we have a tendency to shift around quite a bit at night. According to a study involving 664 sleepers, on average, participants slept on their side 54% of the time, their back 37% of the time, and their front 7% of the time. Males are more likely to change positions throughout the night and move their arms, ...
Read more

New DNA Research Unlocks Secrets of Native Rodents’ Rat Race to New Lands

Image
More than 150 different native rodent species from Australia, New Guinea, and Melanesian islands have had their DNA sequenced in recent studies. It provides a fuller understanding of their connections and the circumstances surrounding their expansion throughout the Pacific. The Australian National University's (ANU) Dr. Emily Roycroft, the study's lead author, said native rodents are an interesting but frequently underappreciated evolutionary group. Dr. Roycroft noted that over 150 species in Australia and New Guinea are unique to those regions and include the rakali, sometimes known as the "water rat," which is frequently spotted swimming in the lakes near Canberra. We now know relatively little about the history and development of native rodents, particularly those found in New Guinea. In order to obtain DNA from museum specimens up to 180 years old, including several extinct and secretive species, the study team developed a novel technique. "One Guadalcanal ra...
Read more

A Briefcase-Sized Box Is Already Making Oxygen on Mars

Image
Currently, the Martian atmosphere is in no way hospitable to Earthlings. It is formed primarily of carbon dioxide and is over 100 times less dense than Earth's atmosphere. It would soon stop breathing completely for any individuals who tried to breathe in it. A modest device, about the size of a suitcase, has been consistently extracting breathable oxygen from the Martian atmosphere on that sandy, arid, alien world. In order to manufacture breathing air for a human expedition to the red planet, it is the first demonstration of the processing of in situ resources for human use on another world. Its name is MOXIE (Mars Oxygen In-Situ Resource Utilization (ISRU) Experiment), and it is a device that utilizes electrolysis to separate Martian carbon dioxide into carbon monoxide and oxygen. It is mounted inside NASA's Perseverance rover. According to the researchers, MOXIE produced oxygen seven times as much between February 2021, when Perseverance arrived, until the end of 2021. Acco...
Read more