Computer simulations show evolution of birds crouch likely due to increase in

first_img PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen Play Movie showing all 17 of our computer models, in evolutionary sequence from furthers to closest in relationship to living birds. Credit: John R. Hutchinson The simulation isn’t able to show definitively if the increase in forelimb size, or the shift in stance was responsible for the development of flight, but it certainly seems logical to conclude that it was all part of the same gradual process. Developing a crouched position was necessary the researchers note, to support the increased mass that developed towards the front part of the dinosaurs. But that, they add, also means adding more hind leg muscle to support the crouch—it’s a far less energy efficient posture. They point to real life dinosaur examples, such as Archaeopteryx, Microraptor and the Velociraptor as proof of their theory—each sported shorter tails, bigger forelimbs and a crouched position due to a more forward center of gravity. For many years, the consensus among those who study dinosaurs was that the crouch seen in modern birds was most likely due to a shift in center of balance as tails grew smaller over time. To find out if this was actually the case, the researchers fed data from several types of dinosaurs (mostly archosaurs), modern birds and their closet living relative, crocodiles, into a computer model. Using that information, they built skeletons and then manually covered them with muscle and skin. The computer was then directed to simulate changes in body structure over millions of years of evolution to see how they impacted the center of gravity of evolving dinosaurs. Surprisingly, they found that it wasn’t slowly diminishing tails that caused the animals to shift their stance, it was the development of larger forelimbs, which of course, over many more millions of years, for some, led to the development of wings. Citation: Computer simulations show evolution of birds’ crouch likely due to increase in forelimb size (w/ video) (2013, April 25) retrieved 18 August 2019 from https://phys.org/news/2013-04-simulations-evolution-birds-crouch-due.html Play Movie showing the 3D modelling procedure that we used; here featuring the large dinosaur Allosaurus. Credit: John R. Hutchinson This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Credit: Concept art by Luis Rey Journal information: Nature Muscle reconstruction reveals how dinosaurs stood More information: Linking the evolution of body shape and locomotor biomechanics in bird-line archosaurs, Nature (2013) doi:10.1038/nature12059AbstractLocomotion in living birds (Neornithes) has two remarkable features: feather-assisted flight, and the use of unusually crouched hindlimbs for bipedal support and movement. When and how these defining functional traits evolved remains controversial. However, the advent of computer modelling approaches and the discoveries of exceptionally preserved key specimens now make it possible to use quantitative data on whole-body morphology to address the biomechanics underlying this issue. Here we use digital body reconstructions to quantify evolutionary trends in locomotor biomechanics (whole-body proportions and centre-of-mass position) across the clade Archosauria. We use three-dimensional digital reconstruction to estimate body shape from skeletal dimensions for 17 archosaurs along the ancestral bird line, including the exceptionally preserved, feathered taxa Microraptor, Archaeopteryx, Pengornis and Yixianornis, which represent key stages in the evolution of the avian body plan. Rather than a discrete transition from more-upright postures in the basal-most birds (Avialae) and their immediate outgroup deinonychosauria5, 6, our results support hypotheses of a gradual, stepwise acquisition of more-crouched limb postures across much of theropod evolution, although we find evidence of an accelerated change within the clade Maniraptora (birds and their closest relatives, such as deinonychosaurs). In addition, whereas reduction of the tail is widely accepted to be the primary morphological factor correlated with centre-of-mass position and, hence, evolution of hindlimb posture, we instead find that enlargement of the pectoral limb and several associated trends have a much stronger influence. Intriguingly, our support for the onset of accelerated morpho-functional trends within Maniraptora is closely correlated with the evolution of flight. Because we find that the evolution of enlarged forelimbs is strongly linked, via whole-body centre of mass, to hindlimb function during terrestrial locomotion, we suggest that the evolution of avian flight is linked to anatomical novelties in the pelvic limb as well as the pectoral.Press release Explore further Animal standing or at the midpoint of a step (a). For the animal to balance, forces applied by the feet (red) must match the force of body weight (blue) pointing downwards from the centre of mass (yellow/black). If the centre of mass moves forward (b), then the feet must move forward (and thus the limb must get more crouched) to maintain balance, as in (c). Credit: John R. Hutchinson © 2013 Phys.org PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen (Phys.org) —An international team of researchers working together to discover how, when and why birds have evolved to stand in a crouching position, have come to the conclusion that it was due much more to the growth of forelimbs than a reduction in size of the tail. The team describes in their paper published in the journal Nature, how they built computer simulations to recreate in a virtual sense, the evolution process that led to the crouching position and possibly the evolution of flight.last_img read more

Researchers argue publicly on how well monkeys could talk if their brains

first_img(Phys.org)—A very public argument has erupted between researchers involved in attempting to understand why monkeys cannot speak—in the pages of respected journals. The argument traces its roots back several decades when a group led by Philip Lieberman conducted research on rhesus macaques to better understand why they cannot speak in a human-like manner. They concluded that the vocal abilities of the monkeys were far too limited to allow the monkeys to talk anything like humans—even if they had the proper brain wiring. More information: 1. Philip Lieberman. Comment on “Monkey vocal tracts are speech-ready”, Science Advances (2017). DOI: 10.1126/sciadv.1700442AbstractMonkey vocal tracts are capable of producing monkey speech, not the full range of articulate human speech. The evolution of human speech entailed both anatomy and brains. Fitch, de Boer, Mathur, and Ghazanfar in Science Advances claim that “monkey vocal tracts are speech-ready,” and conclude that “…the evolution of human speech capabilities required neural change rather than modifications of vocal anatomy.” Neither premise is consistent either with the data presented and the conclusions reached by de Boer and Fitch themselves in their own published papers on the role of anatomy in the evolution of human speech or with the body of independent studies published since the 1950s.2. W. Tecumseh Fitch et al. Response to Lieberman on “Monkey vocal tracts are speech-ready”, Science Advances (2017). DOI: 10.1126/sciadv.1701859 This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Photo of Vervet taken in Dar es Salaam, Tanzania by Alexander Landfair. Credit: Wikipedia. Journal information: Science Advances Monkey speak: Macaques have the anatomy, not the brain, for human speechcenter_img Then, late last year, another team led by W. Tecumseh Fitch, published a report on the open access site Science Advances outlining their research which suggested that perhaps some monkeys did have enough vocal abilities to speak many human-like words. That report caused Liberman to pen a Technical Comments piece for Science Advances criticizing the work by Fitch and his team. The rebuke by Lieberman appeared to upset the Fitch team—they subsequently published a Technical Comment of their own, also in Science Advances, pointing out the differences in their work and what Lieberman had found.Fitch and his group argue that they used techniques not available several decades ago when Liberman and his group were doing their monkey throat studies, which included making plaster casts of the throat and other vocal parts. The newer work involved making X-ray videos of live macaques as they engaged in activities like eating or making noises. Fitch and his team claimed their studies proved that monkeys were capable of making far more sounds than Lieberman and his team claimed—enough sounds to put together words. They acknowledged that the vocal abilities would be limited, but likely strong enough to convey meaningful dialog.For his part, Lieberman claims that no amount of additional research could prove that monkeys could talk because they lack some of the basic physical architecture required to do so.The back and forth between the two groups eventually led to an argument over whether a monkey could pronounce long E—as in reed, read or even Reid. Liberman contends that surgery would be required for a monkey to speak any word with a long E in it because they do not have the tongue for it. Meanwhile, Fitch and his group suggested that the importance of long E use in language is still debatable, further incensing Lieberman by calling it mythical. It is still not clear how the argument will end, or if either side will convince the other. © 2017 Phys.org Citation: Researchers argue publicly on how well monkeys could talk if their brains were able (2017, July 10) retrieved 18 August 2019 from https://phys.org/news/2017-07-publicly-monkeys-brains.html Explore furtherlast_img read more

New theory on origin of the asteroid belt

center_img Astronomers identify oldest known asteroid family More information: Sean N. Raymond et al. The empty primordial asteroid belt, Science Advances (2017). DOI: 10.1126/sciadv.1701138AbstractThe asteroid belt contains less than a thousandth of Earth’s mass and is radially segregated, with S-types dominating the inner belt and C-types the outer belt. It is generally assumed that the belt formed with far more mass and was later strongly depleted. We show that the present-day asteroid belt is consistent with having formed empty, without any planetesimals between Mars and Jupiter’s present-day orbits. This is consistent with models in which drifting dust is concentrated into an isolated annulus of terrestrial planetesimals. Gravitational scattering during terrestrial planet formation causes radial spreading, transporting planetesimals from inside 1 to 1.5 astronomical units out to the belt. Several times the total current mass in S-types is implanted, with a preference for the inner main belt. C-types are implanted from the outside, as the giant planets’ gas accretion destabilizes nearby planetesimals and injects a fraction into the asteroid belt, preferentially in the outer main belt. These implantation mechanisms are simple by-products of terrestrial and giant planet formation. The asteroid belt may thus represent a repository for planetary leftovers that accreted across the solar system but not in the belt itself. Journal information: Science Advances © 2017 Phys.orglast_img read more

Evidence found that suggests dwarf planet Ceres is wrinkling

first_img © 2019 Science X Network Explore further Prior research has shown that icy moons such as Europa and Ganymede have rifts on their surfaces that are believed to have formed as they cooled and some ice melted—because water is denser than ice, it forced expansion of the interior, resulting in cracks. Prior research has shown that planets made of rock, such a Mars and Mercury, tend to have wrinkle formations on their surfaces. It is believed that they formed as the planets cooled—when rock cools, it grows denser and contracts, in such cases, forming thrust faults. Such faults are the result of older rock being pushed over younger rock. In this new effort, the researchers report that data from the Dawn spacecraft shows thrust faults on the dwarf planet’s surface.Approximately 940 kilometers across, Ceres is the largest known object in the asteroid belt located between Jupiter and Mars. NASA launched the space probe Dawn back in 2007 for the purpose of studying three of the largest dwarf planets in the asteroid belt, one of which was Ceres. The mission ended last year, but scientists are still studying the data it sent back. The researchers in Spain report finding evidence of fractures, ridges and slopes on the surface and 15 sites that appear to be thrust faults. The existence of such faults suggests that Ceres is shrinking, and as a result, wrinkles are forming on its surface. This finding is surprising, given the icy nature of the dwarf planet. They also noted that the thrust faults were located mostly close to the poles, but they suggest that the surface there might be easier to examine due to lighting conditions. They also propose the idea that Ceres may be shrinking due to the formation of layers of different material beneath the surface. They suggest more research focused on the thrust faults could fill in more details of the history of the dwarf planet. Citation: Evidence found that suggests dwarf planet Ceres is wrinkling (2019, July 2) retrieved 18 August 2019 from https://phys.org/news/2019-07-evidence-dwarf-planet-ceres-wrinkling.html Gravitational data from Dawn suggests dome on Ceres is made of volcanic mud Ceres. Credit: NASA/Jet Propulsion Laboratorycenter_img This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. A team of researchers affiliated with several institutions in Spain has found evidence that suggests the dwarf planet Ceres is experiencing wrinkling on its surface. In their paper published in the journal Nature Astronomy, the group explains their study of data from the Dawn spacecraft and what it revealed. More information: Javier Ruiz et al. Evidence of thrust faulting and widespread contraction of Ceres, Nature Astronomy (2019). DOI: 10.1038/s41550-019-0803-2 Journal information: Nature Astronomylast_img read more

And then there was light

first_imgThis festival of lights showcases the creativity and quality of textiles, crafts and natural products, perfect for indulging in and gifting to friends, family and colleagues. The 80 and more participating craft groups represent regional craft traditions from across India.Try some special gifting options this Diwali with a pick from hand-made organic and perfumed candles, paper lamps, tea lights and hand-carved gourd lanterns. Gadhwal and Upada weaves, vivid woolen shawls to sarees from Chanderi and Maheshwari, garments embellished with regional embroideries from Kutchi Suf, Lambani, Kantha, along with appliqué textiles from Rajasthan will also be on display at the festival. Also Read – ‘Playing Jojo was emotionally exhausting’Traditional jewellery ranging from terracotta, lac to Meenakari, Dhokra and tribal silver will alos be on offer for the visitors alongside pottery, metal crafts, grass weaving and wood carvings, miniature painting and folk art traditions of Madhubani, Phad, Kalamkari and Pattachitra will all be present at the fair providing all with ample options to indulge in. Food from Maharashtra, Himachal and other regions will be available to satiate the taste buds along with cultural performances from across India. Also Read – Leslie doing new comedy special with Netflix‘Diwali lights lamps both in our homes and in our hearts. It is a time of sharing and giving; and what better gift than something hand-crafted. Something which an artisan has spent time and love, and which represents our culture and traditions,’ says Dastkar’s Chairperson, Laila Tyabji.Pamper yourself with some retail therapy before markets get too crowded. Head over! WHERE: Nature Bazaar Venue, Andheria Modh WHEN: 10 October till 19 October, 11.00 am – 7.30 pm ENTRY: Rs. 20last_img read more

Mamata urges people to end plastic pollution

first_imgKolkata: In a tweet on the occasion of Earth Day, West Bengal Chief Minister Mamata Banerjee has urged people to put an end to plastic pollution to ensure a clean environment. “On the occasion of Earth Day, let us pledge to keep our environment clean. We can take a step in this direction by putting an end to plastic pollution,” Banerjee tweeted this morning.Earth Day is an annual event celebrated worldwide on April 22 to demonstrate support for environmental protection.last_img

Handicraft hub

first_imgThe 39th edition of the Indian Handicrafts and Gifts Fair (spring), 2015 organized by the Export Promotion Council for Handicrafts [EPCH] will be held from February 20-23 at India Expo Centre and Mart, Greater Noida, NCR Delhi. About 2524 exhibitors, including 900 permanent marts, drawn from all over India, spread over in 12 exhibition halls shall be displaying their products exclusively designed for display during the fair.The Indian Handicrafts and Gifts Fair is one of the most important sourcing event for the international buyers. The fair has helped the handicrafts sector in diversifying its product range and creating new markets worldwide. “On an average 4000-5000 buyers from more than 60 countries have been visiting this fair to source their requirements,” informed Rakesh Kumar, Executive Director – EPCH.Two seminars entitled Opportunities and Export strategies for Handicrafts products in Latin America and Caribbean Region and Effective use of Digital Marketing and Online Promotion for Handicrafts Sector will be held on February 21 and 22 during the fair.last_img read more

Jadavpur Kalyani varsity VCs granted Honorary Colonel rank

first_imgKolkata: Indian government on Monday conferred the rank of ‘Colonel’ to the Vice-Chancellor (V-C) of Jadavpur University (JU) Professor Suranjan Das and Professor Sankar Kumar Ghosh of Kalyani University. The duo was appointed as ‘Colonel Commandant’ in the National Cadet Corps (NCC) at an event at Fort William.The guest of honour at the event was state Education minister Partha Chatterjee while Lt. Gen PP Malhotra, VSM, DG NCC was the chief guest. Several dignitaries from the Indian Army were also present. The V-Cs sported uniforms of the conferred ranks while the two guests pinned the accoutrements onto the uniforms of both the Vice-Chancellors. Also Read – Heavy rain hits traffic, flightsIn his address, Chatterjee said: ” I convey my best wishes to the Army and NCC for conferring this prestigious ‘Colonel’ rank to both the esteemed V-Cs of Jadavpur and Kalyani University and appointing them as ‘Colonel Commandant’ in NCC. It is indeed a gold-letter day. The professionalism and commitment with which the Army officers and instructors are training the cadets is praiseworthy.”JU V-C Suranjan Das said: “It is recognition for the entire state than just for an individual. It is an overall recognition for higher education in this state. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedSankar Kumar Ghosh, V-C of KU said: “We have an NCC academy on our campus and we are interacting with the youth and promoting them towards nationalism.”It may be mentioned that the conferring of the rank of the Colonel Commandant aims at increased patronage and purposeful association for the furtherance of NCC activities. It also enhances interaction of Vice-Chancellors with cadets and officers to help and guide them through their educational and NCC career.last_img read more

Mamata worried about tourists stuck in Dras due to landslide

first_imgKolkata: Chief Minister Mamata Banerjee expressed concern over the tourists from Bengal who got stuck in Dras following a landslide, and directed senior officials to take necessary steps for their safety and security.A group of people from Konanagar in Hooghly had gone for a trip to Kashmir, Leh and Ladakh and got stuck on their way back from Leh and Ladakh. A Landslide took place on Tuesday at Saitani Nalah, which is situated between Dras and Sonmarg, leaving the tourists stranded on their way back from Leh and Ladakh. Also Read – Heavy rain hits traffic, flightsAll tourists were taken back to Dras, the sub-divisional headquarters, where there are hotels, hospitals and habitation. The Chief Minister, who is in Kalimpong at present, directed officials of the state government to take necessary steps on an immediate basis, to ensure that the tourists do not face any problem and return safely to their homes.Senior officials of the state government contacted officials of Kashmir administration. It has been learnt that officials from Kashmir administration are extending all help to those who are stuck in Dras. They have given food and water to the stranded tourists. The local administration has also made necessary arrangements to provide medical assistance to the tourists, who are stuck at the place since Tuesday. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedThe state government officials have also come to know that the work of clearing the road is going on in full swing and would be done by Thursday afternoon. As soon as the road is cleared and it is declared safe for vehicles to ply, initiatives would be taken to help the tourists return home. The state Tourism department has also opened a helpline number (033-22358271/033-22358272), on which people can contact for any assistance.So far, there is information of about 22 people from Bengal getting stuck in Dras.last_img read more