Bird, primate, alligator brains and intelligence


This video from the USA says about itself:

Bird Brain: Smarter Than You Think

13 June 2016

The first study to systematically measure the number of neurons in the brains of birds has found that they have significantly more neurons packed into their small brains than are stuffed into mammalian and even primate brains of the same mass.

From the University of Chicago Medical Center in the USA:

Birds and primates share brain cell types linked to intelligence

Bird and reptile brains have a vastly different anatomy from mammalian brains, but contain cell types linked to mammalian cognitive abilities

February 15, 2018

Summary: In a new study scientists show that some neurons in bird brains form the same kind of circuitry and have the same molecular signature as cells that enable connectivity between different areas of the mammalian neocortex. The researchers found that alligators share these cell types as well, suggesting that while mammal, bird and reptile brains have very different anatomical structures, they operate using the same shared set of brain cell types.

Neuronal cell types in the brains of birds linked to goal-directed behaviors and cognition are similar to cells in the mammalian neocortex, the large, layered structure on the outer surface of the brain where most higher-order processing takes place.

In a new study, published this week in the journal Current Biology, scientists from the University of Chicago show that some neurons in bird brains form the same kind of circuitry and have the same molecular signature as cells that enable connectivity between different areas of the mammalian neocortex. The researchers found that alligators share these cell types as well, suggesting that while mammal, bird and reptile brains have very different anatomical structures, they operate using the same shared set of brain cell types.

Birds are more intelligent than you think, and they do clever things. So, the question is: What kind of brain circuitry are they using?” said Clifton Ragsdale, PhD, professor of neurobiology at UChicago and senior author of the study. “What this research shows is that they’re using the same cell types with the same kinds of connections we see in the neocortex, but with a very different kind of organization.”

Both the mammalian neocortex and a structure in the bird brain called the dorsal ventricular ridge (DVR) develop from an embryonic region called the telencephalon. However, the two regions mature into very different shapes. The neocortex is made up of six distinct layers while the DVR contains large clusters of neurons called nuclei.

Because of this different anatomy, many scientists proposed that the bird DVR does not correspond to the mammalian cortex but is instead analogous to another mammalian brain structure called the amygdala.

In 2012, Ragsdale and his team confirmed a 50-year-old hypothesis by University of California San Diego neuroscientist Harvey Karten that proposed the DVR performs a similar function to the neocortex, but with dramatically different anatomy. In that study, the UChicago researchers matched genetic markers of the “input” and “output” neurons of the mammalian neocortex with genes expressed in several bird DVR nuclei.

In the new study, led by graduate student Steven Briscoe, the team found that other populations of neurons in the bird DVR share molecular signatures with neocortical intratelencephalic cells, or IT neurons. These IT neurons form a critical link in the circuitry of the neocortex. They help communicate between different neocortical layers and across cortical areas from one side of the brain to the other. The team then extended their work from birds to reptiles and identified IT neurons in a similar place in the alligator DVR.

“The structure of the avian DVR looks nothing like the mammalian neocortex, and this has historically been a huge problem in comparative neuroscience”, Briscoe said. “Anatomists have debated how to compare the DVR and neocortex for over a century, and our identification of IT neurons in the bird DVR helps to explain how such different brain structures can give rise to similar behaviors.”

The research suggests an interesting possibility that birds and primates evolved intelligence independently, developing vastly different brain structures but starting with the same shared sets of cell types.

“The input cell types, the output cell types and the intratelencephalic cell types are all conserved. They’re not just found in mammals, which we knew, but in non-avian reptiles like alligators and avian reptiles, or birds,” Ragsdale said. “It begins to clarify where and how in evolution we got this fantastic structure, the neocortex.”

Advertisements

Ring-tailed lemurs of Madagascar


This video says about itself:

25 December 2017

In Madagascar, a small piece of rainforest holds an inspiring conservation story. See how a group of local people have banded together to protect the island’s much-loved ring-tailed lemur in this short film by Robin Hoskyns.

South Africa’s oldest Australopithecus fossil


This video from South Africa says about itself:

6 December 2017

The Australopithecus fossil, Little Foot, was discovered by Wits [University of the Witwatersrand] palaeoanthropologist Ron Clarke.

From the University of the Witwatersrand in South Africa:

Litte Foot takes a bow

South Africa’s oldest, and the world’s most complete Australopithecus skeleton ever found, introduced to the world

December 6, 2017

South Africa’s status as a major cradle in the African nursery of humankind has been reinforced with today’s unveiling of “Little Foot”, the country’s oldest, virtually complete fossil human ancestor.

Little Foot is the only known virtually complete Australopithecus fossil discovered to date. It is by far the most complete skeleton of a human ancestor older than 1.5 million years ever found. It is also the oldest fossil hominid in southern Africa, dating back 3.67 million years. The unveiling will be the first time that the completely cleaned and reconstructed skeleton can be viewed by the national and international media.

Discovered by Professor Ron Clarke from the Evolutionary Studies Institute at the University of the Witwatersrand in Johannesburg, South Africa, the fossil was given the nickname of “Little Foot” by Prof. Phillip Tobias, based on Clarke’s initial discovery of four small footbones. Its discovery is expected to add a wealth of knowledge about the appearance, full skeletal anatomy, limb lengths and locomotor abilities of one of the species of our early ancestral relatives.

“This is one of the most remarkable fossil discoveries made in the history of human origins research and it is a privilege to unveil a finding of this importance today,” says Clarke.

After lying undiscovered for more than 3.6 million years deep within the Sterkfontein caves about 40km north-west of Johannesburg, Clarke found several foot bones and lower leg bone fragments in 1994 and 1997 among other fossils that had been removed from rock blasted from the cave years earlier by lime miners. Clarke sent his assistants Stephen Motsumi and Nkwane Molefe into the deep underground cave to search for any possible broken bone surface that might fit with the bones he had discovered in boxes. Within two days of searching, they found such a contact, in July 1997.

Clarke realised soon after the discovery that they were on to something highly significant and started the specialised process of excavating the skeleton in the cave up through 2012, when the last visible elements were removed to the surface in blocks of breccia. “My assistants and I have worked on painstakingly cleaning the bones from breccia blocks and reconstructing the full skeleton until the present day,” says Clarke.

In the 20 years since the discovery, they have been hard at work to excavate and prepare the fossil. Now Clarke and a team of international experts are conducting a full set of scientific studies on it. The results of these studies are expected to be published in a series of scientific papers in high impact, peer reviewed international journals in the near future.

This is the first time that a virtually complete skeleton of a pre-human ancestor from a South African cave has been excavated in the place where it was fossilised.

“Many of the bones of the skeleton are fragile, yet they were all deeply embedded in a concrete-like rock called breccia,” Clarke explains.

“The process required extremely careful excavation in the dark environment of the cave. Once the upward-facing surfaces of the skeleton’s bones were exposed, the breccia in which their undersides were still embedded had to be carefully undercut and removed in blocks for further cleaning in the lab at Sterkfontein,” says Clarke.

The 20-year long period of excavation, cleaning, reconstruction, casting, and analysis of the skeleton has required a steady source of funding, which was provide by the Palaeontological Scientific Trust (PAST) — a Johannesburg-based NGO that promotes research, education and outreach in the sciences related to our origins. Among its many initiatives aimed at uplifting the origin sciences across Africa, PAST has been a major funder of research at Sterkfontein for over two decades.

Professor Adam Habib, Vice-Chancellor and Principal of the University of the Witwatersrand says: “This is a landmark achievement for the global scientific community and South Africa’s heritage. It is through important discoveries like Little Foot that we obtain a glimpse into our past which helps us to better understand our common humanity.”

PAST’s chief scientist Professor Robert Blumenschine labels the discovery a source of pride for all Africans. “Not only is Africa the storehouse of the ancient fossil heritage for people the world over, it was also the wellspring of everything that makes us human, including our technological prowess, our artistic ability, and our supreme intellect,” he says.

The scientific value of the find and much more will be unveiled in a series of papers that Prof Clarke and a team of international experts have been preparing, with many expected in the next year.

Eocene little primates discovered in China


This 2015 video is called Evolution of primates.

From Northern Illinois University in the USA:

Finger and toe fossils belonged to tiny primates 45 million years ago

November 9, 2017

Summary: A new study identifies nearly 500 minuscule finger and toe bones as belonging to 45-million-year-old tiny primates. Many of the fossils are so small they rival the diminutive size of a mustard seed. Representing nine different taxonomic families of primates and as many as 25 species, the specimens from China include numerous fossils attributed to Eosimias, the very first anthropoid known to date, and three fossils attributed to a new and more advanced anthropoid.

At Northern Illinois University, Dan Gebo opens a cabinet and pulls out a drawer full of thin plastic cases filled with clear gelatin capsules. Inside each numbered capsule is a tiny fossil — some are so small they rival the diminutive size of a mustard seed.

It’s hard to imagine that anyone would be able to recognize these flecks as fossils, much less link them to an ancient world that was very different from our own, yet has quite a bit to do with us — or the evolution of us.

The nearly 500 finger and toe bones belonged to tiny early primates — some half the size of a mouse. During the mid-Eocene period, about 45 million years ago, they lived in tree canopies and fed on fruit and insects in a tropical rainforest in what is now China.

The fossilized phalanges are described in detail in a new study by Gebo and colleagues, published online this fall ahead of print in the Journal of Human Evolution.

Representing nine different taxonomic families of primates and as many as 25 species, the specimens include numerous fossils attributed to Eosimias, the very first anthropoid known to date, and three fossils attributed to a new and much more advanced anthropoid. The anthropoid lineage would later include monkeys, apes and humans.

“The fossils are extraordinarily small, but in terms of quantity this is the largest single assemblage of fossil primate finger and toe specimens ever recorded,” said Gebo, an NIU professor of anthropology and biology who specializes in the study of primate anatomy.

All of the finger and toe fossils imply tree-dwelling primates with grasping digits in both hands and feet. Many of the smaller fossils are between 1 and 2 millimeters in length, and the animals would have ranged in full body size from 10 to 1,000 grams (0.35 to 35.3 ounces).

“The new study provides further evidence that early anthropoids were minuscule creatures, the size of a mouse or smaller,” Gebo said. “It also adds to the evidence pointing toward Asia as the initial continent for primate evolution. While apes and fossil humans do come from Africa, their ancestors came from Asia.”

The newly described fossils were originally recovered from a commercial quarry near the village of Shanghuang in the southern Jiangsu Province of China, about 100 miles west of Shanghai. In recent decades, Shanghuang has become well-known among paleontologists.

“Shanghuang is truly an amazingly diverse fossil primate locality, unequaled across the Eocene,” Gebo said. “Because no existing primate communities show this type of body-size distribution, the Shanghuang primate fauna emphasizes that past ecosystems were often radically different from those we are familiar with today.”

Co-author Christopher Beard, a paleontologist at the University of Kansas in Lawrence who has been working on Shanghuang fossils for 25 years, said the limestone in the quarry is of Triassic age — from the very beginning of the Age of Dinosaurs some 220 million years ago. Owing to a subsequent phase of erosion, the limestone developed large fissures containing fossil-rich sediments dating to the middle Eocene, after dinosaurs went extinct.

In the early 1990s, more than 10 tons of fossil-bearing matrix were collected from the fissures and shipped to the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing and the Carnegie Museum of Natural History in Pittsburgh. There, the matrix was washed and screened, yielding fossil bones and teeth from ancient mammals, many of which remain to be identified.

“Because of commercial exploitation of the quarry site, the fossil-bearing fissure-fillings at Shanghuang are now exhausted,” Beard said. “So, the fossils that we currently have are all that will ever be found from this site.”

Gebo was initially recruited during the late 1990s to spearhead research on primate limb and ankle bones from Shanghuang. That led to two publications in 2000, when he and colleagues first announced the discovery of 45 million-year-old, thumb-length primates, the smallest ever recovered, from this same site. The work identifying body parts also helped cement the status of Eosimias, first identified by Beard on the basis of jaw fragments discovered at the site, as an extremely primitive anthropoid lying at the very beginning of our lineage’s evolutionary past.

In more recent years, Gebo found additional specimens, sifting through miscellaneous elements from Shanghuang both at the Carnegie Museum and the University of Kansas. He brought the delicate and minuscule finger and toe fossils to NIU for study using traditional and electron-scanning microscopes.

The fossils that endured the millennia may be small but still have a story to tell. “We can actually identify different types of primates from the shapes of their fingers and toes,” Gebo said.

Primates are mammals, characterized by having bigger brains, grasping hands and feet, nails instead of claws and eyes located in the front of the skull. Living prosimians, or living lower primates, include lemurs and tarsiers, and have broader fingertips. In contrast, most living anthropoids, also known as higher primates, have narrow fingertips.

Fossils from the unnamed advanced anthropoid are narrow, Gebo said.

“These are the earliest known examples of those narrow fingers and toes that are key to anthropoid evolution,” he added. “We can see evolution occurring at this site, from the broader finger or toe tips to more narrow.”

Unlike other prehistoric forests across the globe that have a mixture of large and small primates, Shanghuang’s fossil record is unique in being nearly absent of larger creatures.

The unusual size distribution is likely the result of a sampling bias, Gebo said. Researchers might be missing the larger primate fauna because of processes affecting fossil preservation, and for similar reasons scientists at other Eocene localities could be missing the small-sized fauna.

“Many of the fossil specimens from Shanghuang show evidence of partial digestion by predatory birds, which may have specialized on preying upon the small primates and other mammals that are so common at Shanghuang, thus explaining the apparent bias toward small fossil species there,” Beard added.

Some of the primate fossils found in Shanghuang are found in other countries. Eosimias fossils have been recovered in Myanmar, for example. But Shanghuang stands out because of the presence of more advanced anthropoids and the sheer diversity of primates.

“You don’t find all of these fossil primates in one place except at Shanghuang,” Gebo said.

Ancestor of apes, humans weighed five kilograms


Apes, humans family tree, image courtesy of University of Tübingen

From the American Museum of Natural History in the USA:

Last common ancestor of humans and apes weighed about five kilograms

Ape ancestor was about the size of a gibbon

October 12, 2017

New research suggests that the last common ancestor of apes — including great apes and humans — was much smaller than previously thought, about the size of a gibbon. The findings, published today in the journal Nature Communications, are fundamental to understanding the evolution of the human family tree.

“Body size directly affects how an animal relates to its environment, and no trait has a wider range of biological implications,” said lead author Mark Grabowski, a visiting assistant professor at the Eberhard Karls University of Tübingen in Germany who conducted the work while he was a postdoctoral fellow in the American Museum of Natural History’s Division of Anthropology. “However, little is known about the size of the last common ancestor of humans and all living apes. This omission is startling because numerous paleobiological hypotheses depend on body size estimates at and prior to the root of our lineage.”

Among living primates, humans are most closely related to apes, which include the lesser apes (gibbons) and the great apes (chimpanzees, gorillas, and orangutans). These “hominoids” emerged and diversified during the Miocene, between about 23 million to 5 million years ago. Because fossils are so scarce, researchers do not know what the last common ancestors of living apes and humans looked like or where they originated.

To get a better idea of body mass evolution within this part of the primate family tree, Grabowski and coauthor William Jungers from Stony Brook University compared body size data from modern primates, including humans, to recently published estimates for fossil hominins and a wide sample of fossil primates including Miocene apes from Africa, Europe, and Asia. They found that the common ancestor of apes was likely small, probably weighing about 12 pounds, which goes against previous suggestions of a chimpanzee-sized, chimpanzee-like ancestor.

Among other things, the finding has implications for a behavior that’s essential for large, tree-dwelling primates: it implies that “suspensory locomotion,” overhand hanging and swinging, arose for other reasons than the animal simply getting too big to walk on top of branches. The researchers suggest that the ancestor was already somewhat suspensory, and larger body size evolved later, with both adaptations occurring at separate points. The development of suspensory locomotion could have been part of an “arms race” with a growing number of monkey species, the researchers said. Branch swinging allows an animal to get to a prized and otherwise inaccessible food — fruit on the edges of foliage — and larger body would let them engage in direct confrontation with monkeys when required.

The new research also reveals that australopiths, a group of early human relatives, were actually on average smaller than their ancestors, and that this smaller size continued until the arrival of Homo erectus.

“There appears to be a decrease in overall body size within our lineage, rather than size simply staying the same or getting bigger with time, which goes against how we generally think about evolution,” Grabowski said.

Scientists have been studying for the first time the original fossil remains conserved of “Peking Man.” These six teeth belonging to Homo erectus were found in the mid-twentieth century at the Middle Pleistocene archaeological site of Zhoukoudian (Beijing): here.

Slow lorises saved from criminal pet trade


This video says about itself:

Slow Lorises Rescued From Illegal Pet Trade | National Geographic

3 October 2017

Officials in West Sumatra, Indonesia, rescued nine slow lorises from being sold on the illegal pet market.

Small primate species discovered in Angola


This 2011 video from Tanzania says about itself:

Andrew Perkin and Johan Karlsson conducting a galago [Galagoides] survey in Zanzibar.

From Sci-News.com:

Galagoides kumbirensis: New Species of Dwarf Galago Discovered in Angola

Apr 10, 2017 by Enrico de Lazaro

An international group of primatologists has discovered a new primate, Galagoides kumbirensis (Angolan dwarf galago), with features not been seen by science before.

Galagos, also known as bushbabies, are small, woolly, long-tailed primates that are widespread over sub-Saharan Africa, and make up the family Galagidae.

Over the last half century, their number of species recognized has slowly climbed from 6 to 19 species (including the new one).

The newly-discovered species, the Angolan dwarf galago, belongs to the genus Galagoides (dwarf galagos, or dwarf bushbabies).

“This new species is a very exciting discovery,” said Dr. Russell Mittermeier of Conservation International.

“It is only the fifth new primate described from the African mainland since 2000 and only the second species of galago. What is more, it is from Angola, where there has been very little primate research to date.”

The Angolan dwarf galago is a small gray-brown galago with a darker, long-haired tail.

It is the largest known dwarf galago: the typical head-and-body length for this species is from 6.7 to 7.9 inches (17-20 cm), and the tail varies from 6.7 to 9.5 inches (17-24 cm) long.

This new species is described in a paper published online recently in the American Journal of Physical Anthropology.

“Muzzle slightly up-turned, pink below and dark above, merging into dark eye-rings with a conspicuous white nose stripe between the eyes,” the authors wrote in the paper.

“The remainder of the face gray, suffused with brown, and set off from white cheeks, chin, and neck.”

“Inner ears white towards the base and yellowish towards margins. Ears gray above with two light spots where the ears join the crown. Crown, dorsum forelimbs, thighs, and flanks gray with a brown wash.”

“Ventrum, surface of forelimbs and hindlimbs creamy yellow. Yellow strongest where the light ventrum merges into the darker dorsum.”

“Tail darker towards the tip and slightly longer than the body. Tail held curled when at rest.”

The morphology and calls of the Angolan dwarf galago are so unique that there was no need to resort to genetic techniques to verify it further.

“When we first encountered the new species in Kumbira Forest in north-western Angola, we heard a distinctive ‘crescendo’ call similar to that of a tiny galago, but upon seeing one, we were struck by its remarkably large size,” said lead author Magdalena Svensson, a researcher with the Nocturnal Primate Research Group at Oxford Brookes University.

“Until now, call types have been the most reliable way to distinguish galago species, and to find one that did not match what we expected was very exciting.”

“The uncovering of this species is characteristic of the return of real biology,” said co-author Prof. Judith Masters, from Nelson Mandela Metropolitan University in South Africa.

“Although DNA has yielded new and sometimes highly contestable specimens, in the case of this new galago, the differences are obvious for all to see.”