The Biology, Agriculture, and Paleontology thread

Modern genetics confirm ancient relationship between fins and hands: "Efforts to connect the evolutionary transition from fish fins to wrist and fingers with the genetic machinery for this adaptation have fallen short because they focused on the wrong fish. Now, researchers describe the genetic machinery for autopod assembly in a non-model fish, the spotted gar."

Lightweight skeletons of modern humans have recent origin: "New research shows that modern human skeletons evolved into their lightly built form only relatively recently—after the start of the Holocene about 12,000 years ago and even more recently in some human populations. The work, based on high-resolution imaging of bone joints from modern humans and chimpanzees as well as from fossils of extinct human species shows that for millions of years extinct humans had high bone density until a dramatic decrease in recent modern humans. Published this week in the Proceedings of the National Academy of Sciences, the findings reveal a higher decrease in the density of lower limbs than in that of the upper limbs, suggesting that the transformation may be linked to humans' shift from a foraging lifestyle to a sedentary agricultural one."

Wild gorilla creates a food tool in 'eureka' moment: "It’s a scene that would grace the opening of any Planet of the Apes movie.

But rather than being fiction, this is fact, and one that is new to science.

For the first time, a gorilla in the wild has been seen using a tool to acquire and eat food."

Of bugs and brains: Striking similarities in brain structures across invertebrates: "The fundamental structures underlying learning and memory in the brains of invertebrates as different as a fruit fly and an earthworm are remarkably similar, according to neuroscientists. It turns out that the structure and function of brain centers responsible for learning and memory in a wide range of invertebrate species may possibly share the same fundamental characteristics."

Scientists discover oldest stone tool ever found in Turkey: "Scientists have discovered the oldest recorded stone tool ever to be found in Turkey, revealing that humans passed through the gateway from Asia to Europe much earlier than previously thought, approximately 1.2 million years ago."

Spectacular real virgin births: "Virgin births are no longer rare. They happen everywhere, in ways we still don't fully understand"

Seals discovered having sex with penguins

WTF?

Posted that one long ago.

Pros of incest outweigh cons for mongooses: "If you find yourself looking around the table over the holiday and thinking, 'I can’t believe I’m related to these people,' just be glad you’re not a mongoose. If you were, you might be thinking, 'I can’t believe I’ve mated with all of these people.' For the cat-sized mammals, native to central and east Africa, it’s safer to have sex with a close relative than risk death by venturing out into the world to find a mate, according to a study published online today in Biology Letters. Newly formed mongoose groups have a mortality rate three times higher than that of established ones, and mongooses that encroach on neighboring groups are often met with violence."

Optogenetics captures neuronal transmission in live mammalian brain: "Swiss scientists have used a cutting-edge method to stimulate neurons with light. They have successfully recorded synaptic transmission between neurons in a live animal for the first time."

The octopus that strangled its lover to death

The truth about sloths: "Sloths have a reputation for being lazy, stupid and smelly. The reality is far more impressive, and bizarre"

Australian researchers have mapped the genome of the first marsupial: " Researchers from the Institute for Applied Ecology at the University of Canberra have managed to map the chromosomes of the ancestor of modern marsupials, which lived around 80 million years ago.

Throughout evolution, chromosomes undergo many changes as cells divide, with DNA being randomly mutated and the arrangement of genes being mixed up. These changes result in different species and the range of traits we see in animals today.

Thanks to the new discovery, scientists are now a step closer to tracking how the evolution of mammals led to the two distinct mammalian groups - the eutherians (which include humans, cats, dogs, etc.) and the marsupials (opossums, koalas, kangaroos)."

Drunk birds “slur” their songs, just like us: "Scientists have found that at a blood alcohol level of around 0.08 percent (which would make anyone pretty drunk), birds slur their songs.

It may sound like pointless research, but the scientists are hoping the study will provide insight into human speech and how it's regulated by our brains.

Anyone who's been to a pub will know that humans slur when we get drunk, which suggests that alcohol is affecting something in our brains that controls speech, but up until now this process has been very poorly understood - and as humans are one of the only animals that “talk”, it’s a hard phenomenon to study.

But research has shown that birds learn to sing in much the same way that human babies learn to talk, and so the team from Oregon Health and Science University in the US, decided to test whether alcohol has a similar effect on zebra finches as humans."

I really like these things. Speculative evolution artwork can be really awesome.

Plant genetic advance could lead to more efficient conversion of plant biomass to biofuels: "Plant geneticists including Sam Hazen at the University of Massachusetts Amherst and Siobhan Brady at the University of California, Davis, have sorted out the gene regulatory networks that control cell wall thickening by the synthesis of the three polymers, cellulose, hemicellulose and lignin.

The authors say that the most rigid of the polymers, lignin, represents 'a major impediment' to extracting sugars from plant biomass that can be used to make biofuels. Their genetic advance is expected to "serve as a foundation for understanding the regulation of a complex, integral plant component" and as a map for how future researchers might manipulate the polymer-forming processes to improve the efficiency of biofuel production."

Yeah, but cutting down on lignin production seems to be problematic because it's going to severely hamper the growth of the plant past a certain (not very tall) height.

New perspective on snake evolution: "Snakes may not have shoulders, but their bodies aren't as simple as commonly thought, according to a new study that could change how scientists think snakes evolved. Rather than snakes evolving from a lizard ancestor to a more simplified body form, researchers say their findings suggest other animals gained more complex vertebral columns as they evolved."

Study casts doubt on mammoth-killing cosmic impact: "Rock soil droplets formed by heating most likely came from Stone Age house fires and not from a disastrous cosmic impact 12,900 years ago, according to new research. The study, of soil from Syria, is the latest to discredit the controversial theory that a cosmic impact triggered the Younger Dryas cold period."

Computer model explains how animals select actions with rewarding outcomes: "A computer model charting what happens in the brain when an action is chosen that leads to a reward has been developed by researchers. The model could provide new insights into the mechanisms behind motor disorders such as Parkinson's Disease. It may also shed light on conditions involving abnormal learning, such as addiction."

'Bearded' female lizards turn off males, but have secret advantages: "A century ago, the cast of circus characters often included bearded ladies, women with decidedly manlike facial hair. Eastern fence lizards have their own bearded ladies. Males sport prominent blue patches on their undersides, and many females have smaller, lighter blue splotches on their chests and necks. Female lizards find the blue in potential mates quite sexy, so evolution has favored brighter patches. But male lizards are turned off by blue females, so it’s a mystery why females have any blue at all.

Tracy Langkilde has some clues. A biologist at Pennsylvania State University,University Park, she and her colleagues have evaluated how blueness affects female lizards. Although there are some downsides to being blue, bearded females run faster and have young that survive better than do offspring of nonblue peers, Langkilde reported here this week at the annual meeting of the Society for Integrative and Comparative Biology."

Study of ancient dogs in the Americas yields insights into human, dog migration: "A new study suggests that dogs may have first successfully migrated to the Americas only about 10,000 years ago, thousands of years after the first human migrants crossed a land bridge from Siberia to North America.

The study looked at the genetic characteristics of 84 individual dogs from more than a dozen sites in North and South America, and is the largest analysis so far of ancient dogs in the Americas. The findings appear in the Journal of Human Evolution."

Why birds crash into planes

Basically it's because birds pay more attention to distance than speed, which works well with birds of prey, but not so much with jet planes.

edited 7th Jan '15 2:08:36 PM by rmctagg09

Devil is in the detail: Evolution of color in plants and animals: "Researchers have looked at a species of fish to help unravel one of the biggest mysteries in evolutionary biology. "The importance of this work lies in the fundamental question: how and why do variants of the same animal exist in nature," researchers explain."

Chimpanzees drum with signature style: "Sometimes a male chimp just needs to drum. Hooting and hollering, he gallops up to the giant buttress root of a tree, grips its crest with his hands, and beats on its wall-like surface with both feet, making a racket that can be heard more than a kilometer away. Now, new research from Uganda suggests these drum solos contain signature rhythmic patterns that may telegraph an individual’s whereabouts to distant troopmates. The findings could provide insight into how rhythm first evolved in humans."

Timid rats use the buddy system: "A friend can make even the shiest creature bold. Rats usually fear strange open spaces, but having a companion by their side makes the rodents more intrepid, scientists report in the current issue of Animal Cognition."

New insight on skull development in study of frogs: "Chances are, you'd be hard-pressed to name something you have in common with a chicken. Would you believe that one answer is the head on your shoulders?

For more than a century, scientists have attempted to understand how the bones of the skull develop in vertebrate embryos. Most have concluded that a single developmental pattern—first described in chickens—applies to all vertebrates.

A new study conducted by Harvard researchers suggests that this may not be entirely true."

Shark stores sperm for 4 years before having a pup, a new record: "A brownbanded bamboo shark seems to have fertilized her eggs with sperm she held onto for 45 months, according to researchers at the California Academy of Sciences. That's the stingiest sperm storage ever seen in any species of shark.

Like chickens, many sharks will produce and drop unfertilized eggs. So biologists at the California Academy of Sciences' Steinhart Aquarium didn't pay much attention to the egg casings littering their all-female Shark Lagoon.

But when they decided to take a closer look in 2010, they found that two of the egg casings were housing healthy shark embryos. One of them survived, and in 2012 a healthy shark pup was born."

They see flow signals: Researchers identify nature of 'sixth sense' in fish: "A team of scientists has identified how a "sixth sense" in fish allows them to detect flows of water, which helps resolve a long-standing mystery about how these aquatic creatures respond to their environment."

Two-faced fish clue that our ancestors 'weren't shark-like': "An investigation of a 415-million-year-old fish skull strongly suggests that the last common ancestor of all jawed vertebrates, including humans, was not very shark-like. It adds further weight to the growing idea that sharks are not 'primitive'.

The fossil skull's external features meant it had always been thought to belong to the bony fishes (osteichthyans), a group which includes familiar fishes such as cod and tuna as well as all land-dwelling creatures with backbones. But when scientists from Oxford University and Imperial College London used X-ray CT scanning to look inside the skull they found the structure surrounding the brain was reminiscent of cartilaginous fishes (chondrichthyans) such as sharks and rays. The fish fossil's 'two faces' led to it being named Janusiscus after the double-faced Roman god Janus."

New Jurassic species of marine reptile identified from fossils in Scotland: "'During the time of dinosaurs, the waters of Scotland were prowled by big reptiles the size of motor boats. Their fossils are very rare, and only now, for the first time we've found a new species that was uniquely Scottish,' says Dr Steve Brusatte of the School of Geo Sciences. 'Without the generosity of the collector who donated the bones to a museum instead of keeping them or selling them, we would have never known that this amazing animal existed.'

The new species - Dearcmhara shawcrossi - is named in honour of an amateur enthusiast, Brian Shawcross, who recovered the creature's fossils from the island's Bearreraig Bay in 1959. Dearcmhara - pronounced 'jark vara' - is Scottish Gaelic for marine lizard, and pays homage to the history of Skye and the Hebrides.

The species is one of the few to have ever been given a Gaelic name."

A wild-born orangutan has learned to communicate like a human: "A female Bornean orangutan living at Cologne Zoo in Germany has figured out how to make human-like calls in order to grab the attention of her keepers when she wants more food.

Named Tilda, she is the fist wild-born orangutan ever known to make human vocalisations, and the ability suggests that other great apes, as well as our ancestors, could have had the same ability."

Slick and slender snake beats short and stubby lizard in sand swimming: "For swimming through sand, a slick and slender snake can perform better than a short and stubby lizard.

That's one conclusion from a study of the movement patterns of the shovel-nosed snake, a native of the Mojave Desert of the southwest United States. The research shows how the snake uses its slender shape to move smoothly through the sand, and how its slippery skin reduces friction - both providing locomotive advantages over another sand-swimmer: the sandfish lizard native to the Sahara Desert of northern Africa.

The study provides information that could help explain how evolutionary pressures have affected body shape among sand-dwelling animals. And the work could also be useful in designing search and rescue robots able to move through sand and other granular materials."

Dinosaurs wiped out rapidly in Europe 66 million years ago: "The well-known theory that an asteroid suddenly killed the dinosaurs is based almost entirely on fossils from North America. A new study shows that dinosaurs — and other continental vertebrates — remained diverse in Europe up until the asteroid impact, 66 million years ago. This is strong evidence that dinosaurs and many of their contemporaries went extinct rapidly and simultaneously all across the globe."

World's oldest butchering tools gave evolutionary edge to human communication: Oldowan technology behind genesis of language and teaching: "Two and a half million years ago, our hominin ancestors in the African savanna crafted rocks into shards that could slice apart a dead gazelle, zebra or other game animal. Over the next 700,000 years, this butchering technology spread throughout the continent and, it turns out, came to be a major evolutionary force."

Stone Age humans weren't necessarily more advanced than Neanderthals: "A multi-purpose bone tool dating from the Neanderthal era has been discovered by researchers, throwing into question our current understanding of the evolution of human behavior. It was found at an archaeological site in France."

Jaw mechanics of a shell-crushing Jurassic fish revealed: "The feeding habits of an unusual 200-million-year-old fish have been uncovered by an undergraduate in a groundbreaking study. The Jurassic fish, Dapedium, known from the Lower Lias rocks of the Dorset coast around Lyme Regis, was one of many new groups of fishes that came on the scene 200 million years ago. These included ancestors of the modern teleost fishes — the group of 30,000 species of salmon, cod, seahorses, and perch — that dominate the waters today."

Out of the pouch: Ancient DNA from extinct giant roos: "Scientists have finally managed to extract DNA from Australia's extinct giant kangaroos—the mysterious marsupial megafauna that roamed Australia over 40,000 years ago.

A team of scientists led by Dr Bastien Llamas and Professor Alan Cooper from the University of Adelaide's Australian Centre for Ancient DNA (ACAD) have extracted DNA sequences from two species: a giant short-faced kangaroo (Simosthenurus occidentalis) and a giant wallaby (Protemnodon anak). These specimens died around 45,000 years ago and their remains were discovered in a cold and dry cave in Tasmania.

Relatively good preservation conditions in the cave allowed enough short pieces of DNA to survive so researchers could reconstruct partial 'mitochondrial genomes'—genetic material transmitted from mother to offspring and widely used to infer evolutionary relationships.

'The ancient DNA reveals that extinct giant wallabies are very close relatives of large living kangaroos, such as the red and western grey kangaroos,' says lead author Dr Bastien Llamas, ACAD senior research associate. 'Their skeletons had suggested they were quite primitive macropods—a group that includes kangaroos, wallabies, pademelons and quokkas—but now we can place giant wallaby much higher up the kangaroo family tree.'"

edited 15th Jan '15 12:42:28 PM by rmctagg09

Tiny plant fossils a window into Earth's landscape millions of years ago: "Scientists have discovered a way to determine the tree cover and density of trees, shrubs and bushes in locations over time based on clues in the cells of plant fossils preserved in rocks and soil. Quantifying vegetation structure throughout time could shed light on how the Earth's ecosystems changed over millions of years."

Contractor Digs Up 14,000-Year-Old Mastodon Skeleton In Neighbor's Backyard: "Sure, finding a bone in someone’s back yard is pretty cool and probably worth telling your friends about. But imagine the excitement when that bone turns out to be the remains of a 14,000 year old prehistoric mammal. That’s exactly what happened recently to contractor Daniel LaPoint Jr. who had been digging up his neighbor’s garden in the US last year.

LaPoint’s discovery began last November when he noticed something massive jutting out of a pile of earth he had excavated from a property in Bellevue Township, Michigan. That something turned out to be a 4-foot-long rib bone, gray with age. Initially, LaPoint thought that the curved bone belonged to a dinosaur, so he excitedly alerted the owner of the property, Erik Witzke, and the duo decided to team up to see what else they might find. After spending four days sweating in the dirt, they unearthed an impressive total of 42 bones.

The team then decided to seek an expert’s opinion on the find, so they contacted scientists at the University of Michigan Museum of Paleontology, who immediately became interested in their discovery. Daniel Fisher, director of the museum, then visited the site and examined the remains. Rather than belonging to a dinosaur, Fisher determined that the owner of the bones was actually a mastodon, a relative of the prehistoric mammoth that lived some 30 million years ago, during the Oligocene, until around 10,000 years ago."

Roller coaster geese: Insights into high altitude bird flight physiology and biomechanics: "A study of the migratory biology of bar-headed geese, during their high altitude flights across the Tibetan plateau and Himalayan Mountains, has revealed how these birds cope with flying in the relatively low-density mountain atmosphere. The study shows that the geese perform a 'roller coaster' ride through the mountains, tracking the underlying terrain even if this means repeatedly shedding hard-won altitude only to have to regain height later in the same or subsequent flight."

Antiquity of dairying on Emerald Isle revealed: "As dairy farmers across Europe anxiously await the lifting of EU milk quotas in April this year, new research from the University of Bristol, UK has revealed the antiquity of dairy farming in a region famous for its dairy exports: Ireland.

Research published today in the Journal of Environmental Archaeology shows that dairying on the island goes back approximately 6,000 years, revealed through traces of ancient dairy fats found in pots dating to around 4,000 to 2,500 BC.

Dr Jessica Smyth of Bristol's School of Chemistry analysed nearly 500 pots from the Neolithic, the period when people switched from hunting and gathering to farming. In Britain and Ireland, this change occurred around 4,000 BC, more than 1,000 years later than on the Continent. The Bristol team use a combination of fat or lipid 'fingerprinting' and compound-specific carbon isotope techniques to identify the origin of fats preserved in the walls of prehistoric cooking pots."

Sharks sink in fresh water: "Sharks may be fearsome predators, but they have a simple weakness: Most can’t tolerate fresh water. About 40% of bony fish, from goldfish to rainbow trout, live in fresh water, but only 5% of elasmobranchs (the sharks, rays, and skates) can manage this feat. Fresh water dehydrates them, dulls their senses, and compromises their reproduction. It also makes them sink, according to a study published online this month in The Journal of Experimental Biology. Unlike more modern fish, with their fancy air bladders, the ancient elasmobranchs have only their oily livers as flotation devices."

Heart arrhythmias detected in deep-diving marine mammals: "A new study of dolphins and seals shows that despite their remarkable adaptations to aquatic life, exercising while holding their breath remains a physiological challenge for marine mammals. The study found a surprisingly high frequency of heart arrhythmias in bottlenose dolphins and Weddell seals during the deepest dives."

Picture this—biosecurity seen from the inside: "When plants come under attack internal alarm bells ring and their defence mechanisms swing into action - and it happens in the space of just a few minutes. Now, for the first time, plant scientists - including experts from The University of Nottingham - have imaged, in real time, what happens when plants beat off the bugs and respond to disease and damage.

The research, 'A fluorescent hormone biosensor reveals the dynamics of jasmonate signalling in plants', was carried out by an interdisciplinary team from the UK, France and Switzerland and has been published in the leading academic journal Nature Communications.

Malcolm Bennett, Professor in Plant Science at The University of Nottingham and Director of the Centre for Plant Integrative Biology, said: 'Understanding how plants respond to mechanical damage, such as insect attack, is important for developing crops which cope better under stress.'"

edited 17th Jan '15 12:51:35 AM by rmctagg09