Tag

Vertebrates

All articles tagged with #vertebrates

science2 days ago•6 min saved

Blood’s Ancestral Blueprint: A 700-Million-Year Link to Single-Celled Ancestors

An international team led by Kyoto University traced the evolution of blood cells back about 700 million years, showing blood likely formed from ancient unicellular gene programs rather than arising anew with multicellular life. By comparing transcriptomes across species, they found macrophage-like ancestors and shared regulatory genes (notably Fos) that link early single-celled organisms to later mast cells, T cells, red blood cells, and platelets, revealing a deep evolutionary history with implications for understanding diseases such as cancer.

via ScienceAlert|

#blood #evolution #macrophages

science28 days ago•4 min saved

Ancient Utah Fossil Rewrites Tunicate Origins

A 500-million-year-old fossil from Utah, Megasiphon thylakos, preserves soft tissues and shows muscle bands akin to modern tunicates, suggesting a non-motile, seafloor-filter-feeding adult with free-swimming larvae; the specimen pushes the origin of tunicates earlier than thought and clarifies their evolutionary link to vertebrates.

via The Daily Galaxy|

#fossil #megasiphon-thylakos #science

science1 month ago•6 min saved

Cyclops-Like Ancestor Illuminates Vertebrate Eye Evolution and Sleep

Researchers trace vertebrate vision to a 600-million-year-old median eye on a worm-like ancestor, which evolved into the brain’s pineal gland and the sleep-regulating melatonin system, explaining why vertebrate eyes are brain-derived and how image-forming vision and circadian rhythms emerged as lineages shifted to more active lifestyles.

via Science Daily|

#circadian-rhythm #evolution #eye

science2 months ago•5 min saved

A lone ancestral eye gave rise to vertebrate vision, new theory claims

Researchers from the University of Sussex and Lund University propose that vertebrate eyes did not evolve from early paired eyes but were reinvented from a single central photoreceptive organ after ancestral deuterostomes lost their eyes. This organ supposedly integrated both rhabdomeric and ciliary photoreceptors, with the pineal gland as a remaining link to this history. Published in Current Biology, the hypothesis offers testable predictions but still requires firmer evidence.

via Ars Technica|

#eye-evolution #photoreceptors #pineal-gland

science3 months ago•7 min saved

600-Million-Year Cyclops Traced as Progenitor of Vertebrate Vision

New research links vertebrate vision to a 600-million-year-old wormlike ancestor that had a single median eye. Over time, that eye’s light-sensing cells organized into the modern image-forming eyes, while the pineal gland remains a direct descendant; this explains why vertebrate retinas develop from brain tissue and why insect and squid eyes originate from skin.

via The Daily Galaxy|

#evolutionary-biology #eye-evolution #median-eye

science3 months ago•1 min saved

From One Eye to Two: Tracing the Deep Origins of Vision

Researchers propose that vertebrate eyes originated from a single ancestral eye in ancient invertebrates around 560 million years ago, later splitting into two—offering a potential answer to how the complex eye evolved and addressing Darwin’s long-standing questions.

via The New York Times|

#darwin #evolution #eyes

science8 months ago•4 min saved

Ghost Sharks' Unique Forehead Teeth Used in Mating

Scientists discovered that the ratfish, a primitive fish, has a unique appendage called a tenaculum with true teeth outside its head, challenging traditional views on tooth placement and suggesting more flexible dental systems in vertebrates.

via Defector|

#evolution #fossil-record #ratfish

science10 months ago•4 min saved

Ancient Fish Challenges Our Evolutionary Understanding

A recent study re-examining the coelacanth, a 'living fossil,' revealed that many previously identified evolutionary traits were incorrect, leading to new insights into vertebrate evolution and showing that coelacanths are more similar to cartilaginous fish and tetrapods than previously thought.

via ScienceDaily|

#coelacanth #evolution #fossil

science11 months ago•7 min saved

Ancient Armored Fish Origin of the 'Tooth Hurty' Joke

Yara Haridy's research on tiny fossils called fish flakes has revealed that early vertebrate teeth evolved from sensory exoskeletons of armored fish, supporting the 'outside-in' theory of tooth development and shedding light on the evolutionary transition from soft-bodied to skeletonized vertebrates.

via Defector|

#ancient-fish #cambrian-period #fossils

science2 years ago•4 min saved

"Evolutionary Insights: Nightmare Fish and the Origin of the Sympathetic Nervous System"

Lampreys, ancient jawless fish, were previously thought to lack a "fight or flight" response due to the absence of a structure called the neural crest. However, a new study published in Nature reveals that lampreys do have sympathetic nerve cells, suggesting that the vertebrate flight-or-flight response is more ancient than previously believed. This discovery sheds light on the evolution of this system and challenges previous assumptions about these primitive vertebrates.

via Livescience.com|

#evolution #fight-or-flight-response #lampreys

science-and-nature2 years ago•2 min saved

"Meet the Brazilian Flea Toad: The World's Tiniest Vertebrate"

Researchers have confirmed that the flea toad, Brachycephalus pulex, found in Brazil, is the tiniest frog and vertebrate species in the world, measuring an average of 7.1 millimeters for adult males. This discovery challenges the previous record held by Papua New Guinea's Paedophryne amauensis. The extremely small size of these frogs presents physical limitations for vertebrates, such as the inability to fit enough cell types to create vital organs and the loss of common frog features. Despite these limitations, the flea toads continue to thrive in their mountainous forest habitats.

via ScienceAlert|

#amphibians #brazil #research

science2 years ago•3 min saved

"Unveiling the Surprising Role of Ancient Viruses in Vertebrate Brain Evolution"

Scientists have discovered a crucial link between ancient viruses and the development of myelination, a process essential for advanced nervous system functioning in vertebrates. The study reveals that a genetic element derived from retroviruses, called "RetroMyelin," is vital for myelin production in a wide range of vertebrates, including mammals, amphibians, and fish. This finding suggests that viral sequences integrated into early vertebrate genomes played a pivotal role in the evolution of myelination, enabling the development of complex brains and diverse vertebrate life. The research sheds light on the molecular mechanisms of myelin production and its evolutionary origins, opening new avenues for understanding the role of retroviruses in directing evolution.

via PsyPost|

#evolution #myelination #neurobiology

science2 years ago•3 min saved

"Evolutionary Impact: Ancient Viruses Shaping Our Bodies and Brains"

A study published in the journal Cell suggests that ancient viruses that infected vertebrates millions of years ago played a crucial role in the evolution of advanced brains and large bodies. Researchers found that a gene sequence acquired from retroviruses is crucial for myelin production, enabling faster nerve impulse conduction and structural support, leading to the development of larger bodies. The study also suggests that the retroviral infection may have occurred multiple times in the evolutionary history of vertebrates, shedding light on the complex relationship between viruses and evolution.

via ScienceAlert|

#ancient-viruses #evolution #genetics

science2 years ago•3 min saved

Unraveling the Hagfish Genome: Insights into Vertebrate Evolution

An international scientific team has successfully sequenced the first genome of myxini, also known as hagfish, which is the only large group of vertebrates without a reference genome. This achievement has provided insights into the evolutionary history of genome duplications in vertebrates, shedding light on the origin of unique vertebrate structures such as the complex brain, jaw, and limbs. The study, which took nearly a decade and involved over 40 authors from seven countries, has significant implications for understanding the genomic events that led to the emergence of key vertebrate characteristics.

via Phys.org|

#evolutionary-history #genome-sequencing #myxini

biology2 years ago•3 min saved

"High-altitude Mice: Earth's Highest-dwelling Vertebrates Found on Volcano Summit"

A study confirms that the world's highest-dwelling vertebrates are small mammals living on the snow-capped tops of volcanoes in the Andes, challenging previous assumptions about the limits of vertebrate life. Researchers discovered live and mummified leaf-eared mice at elevations of up to 22,000 feet, with evidence suggesting that these mice are resident populations rather than transient visitors. The genetic similarity among the high-dwelling rodents and the presence of rodent burrows further support their ability to thrive in these extreme conditions. The mystery of how these mice survive in their frigid habitat remains unsolved, but ongoing research aims to shed light on their diet and thermoregulation.

via Livescience.com|

#andes #biology #high-altitude