Connect with us

Biology

New Evidence Modifies Homo sapiens Chronology and Behavior

blank

Published

on

Homo sapien skulls from Jebed Irhoud
Two reconstructed Homo sapiens skulls recovered from the excavations at Jebel Irhoud, Morocco.

Earlier this month, researchers published an article outlining new evidence from an excavation in Jebel Irhoud (Morocco) that provides the earliest date yet for the presence of Homo sapiens. A variety of dating methods provide an age of about 315,000 years ago (kya). Prior to this, the earliest securely dated evidence for Homo sapiens were the bones from the Omo Kibish site in Ethiopia dating to about 195 kya.

The decades-long excavation at Jebel Irhoud has uncovered various types of palaeo archaeological data. The skeletal material (e.g. skull, mandible, teeth, humerus, hip bone) shows that there were at least five individuals. The assemblage of stone tools includes examples of the Mousterian industry and the Levallois napping technique. Both of these are closely associated with Neanderthals (Homo neanderthalensis), though are not exclusive to the species. Also, the majority of the tools were made from stone not native to the Jebed Irhoud area. Other recovered evidence includes examples of fire use and animal bones (primarily gazelle) showing signs of hunting and butchering.

Dating Methods

A variety of dating techniques helped establish the age of the new assemblage at 315 kya. The research team measured sediment from the different stratigraphic levels for the quantity of radiation present. They used electron spin resonance on bone samples. Finally, the researchers applied thermoluminescence to the stone tools that were in direct association with the bones. Unfortunately, the research team was unable to extract DNA from the bones.

Homo sapiens stone tools from Jebel Irhoud, Morocco

Samples of stone tools recovered from Jebel Irhoud (Morocco).

Importance of Evidence

The importance of the evidence is twofold. First, it secures a mature development of Homo sapiens over 100,000 years earlier than previous evidence indicated. The date does not remove the firm placement of Homo sapiens within the Middle Pleistocene and during the Middle Palaeolithic. However, a date of 315 kya does provide overlap with the existence of Homo heidelbergensis. Previous evidence indicated that Homo sapiens developed from Homo heidelbergensis between 300 – 200 kya. The Jebel Irhoud data do not exclude this hypothesis but it means that Homo sapiens must have developed much earlier, probably closer to the nadir of Homo antecessor. It also means that Homo sapiens had much longer contemporaneity with Homo erectus than previously known.

The second important aspect is the location of the finds. Morocco is around 3,400 miles from Ethiopia. The prevailing models of human evolution place the development of Homo sapiens in Ethiopia. This makes sense based on the quantity and age of data recovered from sites in Ethiopia and in East Africa. The location of the new finds, and the fact that the fossils represent developed Homo sapiens, indicate that our ancestors had already moved across the continent in viable population sizes so the broad evolutionary changes that resulted in our species had already occurred.

The Jebel Irhoud evidence does not lessen the importance of East Africa in understanding the development of our species. Rather, it contributes data to provide a richer, more robust picture of hominid development and migrations across Africa and the world. It is quite exciting to imagine what else the excavation will recover to further elucidate the history of hominids and Homo sapiens. What are your thoughts?

Nature

Archaeology, technology, science, movies and TV shows, video games, government and politics, reading sci-fi and fantasy, '60s/70s classic rock. These are the areas in which I spend my days (somewhere in there are food and travel...).

Biology

The First 3D-Printed Vegan Salmon Is In Stores

blank

Published

on

blank

Revo Foods’ “THE FILET – Inspired By Salmon” salmon fillet may be the first 3D-printed food to hit store shelves. said that firm CEO Robin Simsa remarked, “With the milestone of industrial-scale 3D food printing, we are entering a creative food revolution, an era where food is being crafted exactly according to customer needs.”

Mycoprotein from filamentous fungi is used to make the salmon alternative and other meat substitutes. Vitamins and omega-3 fatty acids are in the product, like in animals. Is high in protein, at 9.5 grams per 100 grams, although less than conventional salmon.

Revo Foods and Mycorena developed 3D-printable mycoprotein. Years of research have led to laser-cooked cheesecakes and stacked lab-grown meats.

One reason for this push is because printed food alternatives may make food production more sustainable, which worries the fishing sector. Overfishing reduces fish populations in 34% of worldwide fish stocks.

Over 25% of worldwide greenhouse gas emissions come from food production, with 31% from livestock and fish farms and 18% from supply chain components including processing and shipping. According to Revo Foods’ website, vegan salmon fillet production consumes 77 to 86% less carbon dioxide and 95% less freshwater than conventional salmon harvesting and processing.

The salmon alternative’s sales potential is unknown. In order to succeed, Revo Foods believes that such goods must “recreate an authentic taste that appeals to the flexitarian market.”

The commercial distribution of 3D-printed food could change food production.

Continue Reading

Artificial Intelligence

Open-source Microsoft Novel protein-generating AI EvoDiff

blank

Published

on

blank

All diseases are based on proteins, natural molecules that perform vital cellular functions. Characterizing proteins can reveal disease mechanisms and ways to slow or reverse them, while creating proteins can lead to new drug classes.

The lab’s protein design process is computationally and human resource-intensive. It involves creating a protein structure that could perform a specific function in the body and then finding a protein sequence that could “fold” into that structure. To function, proteins must fold correctly into three-dimensional shapes.

Not everything has to be complicated.

Microsoft introduced EvoDiff, a general-purpose framework that generates “high-fidelity,” “diverse” proteins from protein sequences, this week. Unlike other protein-generating frameworks, EvoDiff doesn’t need target protein structure, eliminating the most laborious step.

Microsoft senior researcher Kevin Yang says EvoDiff, which is open source, could be used to create enzymes for new therapeutics, drug delivery, and industrial chemical reactions.

Yang, one of EvoDiff’s co-creators, told n an email interview that the platform will advance protein engineering beyond structure-function to sequence-first design. EvoDiff shows that ‘protein sequence is all you need’ to controllably design new proteins.

A 640-million-parameter model trained on data from all protein species and functional classes underpins EvoDiff. “Parameters” are the parts of an AI model learned from training data that define its skill at a problem, in this case protein generation. The model was trained using OpenFold sequence alignment data and UniRef50, a subset of UniProt, the UniProt consortium’s protein sequence and functional information database.

Modern image-generating models like Stable Diffusion and DALL-E 2 are diffusion models like EvoDiff. EvoDiff slowly subtracts noise from a protein made almost entirely of noise to move it closer to a protein sequence.

blank

Beyond image generation, diffusion models are being used to design novel proteins like EvoDiff, create music, and synthesize speech.

“If there’s one thing to take away [from EvoDiff], I think it’s this idea that we can — and should — do protein generation over sequence because of the generality, scale, and modularity we can achieve,” Microsoft senior researcher Ava Amini, another co-contributor, said via email. “Our diffusion framework lets us do that and control how we design these proteins to meet functional goals.”

EvoDiff can create new proteins and fill protein design “gaps,” as Amini noted. A protein amino acid sequence that meets criteria can be generated by the model from a part that binds to another protein.

EvoDiff can synthesize “disordered proteins” that don’t fold into a three-dimensional structure because it designs proteins in “sequence space” rather than structure. Disordered proteins enhance or decrease protein activity in biology and disease, like normal proteins.

EvoDiff research isn’t peer-reviewed yet. Microsoft data scientist Sarah Alamdari says the framework needs “a lot more scaling work” before it can be used commercially.

“This is just a 640-million-parameter model, and we may see improved generation quality if we scale up to billions,” Alamdari emailed. WeAI emonstrated some coarse-grained strategies, but to achieve even finer control, we would want to condition EvoDiff on text, chemical information, or other ways to specify the desired function.”

Next, the EvoDiff team will test the model’s lab-generated proteins for viability. Those who are will start work on the next framework.

Continue Reading

Biology

Chinese Dinosaur Might Have Been as Iridescent as a Hummingbird

blank

Published

on

blank

Earlier this month, I wrote an article on a toy line of scientifically accurate Velociraptor action figures with plumage inspired by modern birds. I mused how impressive it would be if prehistoric raptors had been covered by feather patterns not unlike those in the toy line. Little did I know that two weeks later, researchers would reveal that some theropods had iridescent feathers that outshine David Silva’s velocifigures.

The Caihong juji, Mandarin for “rainbow with a big crest” (or just Caihong for short), was a “paravian theropod,” a clade commonly known for its winged forelimbs (even though many weren’t capable of flight) and enlarged sickle foot claws. In 2014, a farmer in the Qinlong County in the Hebei Province of Northeastern China gave a nearly complete Caihong fossil, feathers included, to The Paleontological Museum of Liaoning. Finding a complete skeleton is rare in paleontology and proved very helpful to the researchers. However, you might wonder just how scientists were able to determine the iridescent nature of the Caihong’s plumage. Two words: fossilized melanosomes.

blank

Melanosomes are organelles that create, store, and transport melanin, which determines the pigments/colors of animal hair, fur, skin, scales, and feathers. Upon examining the Caihong’s head, crest, and tail feathers with an electron microscope, scientists discovered platelet-shaped structures similar in shape to the melanosomes that give hummingbirds their iridescent coloring. The rest of the body feathers had melanosome structures similar to those in the grey and black feathers of penguins, which would have made for an odd sight: a duck-sized dinosaur with body feathers as drab as a raven’s and head and neck feathers more colorful than a peacock’s.

The inferred feather coloration of the Caihong is not its only unusual feature, though. The dinosaur had longer arm and leg feathers than its relatives, and its tail feathers created a “tail surface area” that was larger than the famous proto-bird the Archaeopteryx.  Furthermore, the Caihong had bony crests, which while common among most dinosaurs, are almost unheard of among paravian theropods. But, more importantly, it had proportionally long forearms, which is a feature of flight-capable theropods, even though scientists believe the Caihong didn’t fly. While this dinosaur apparently has the earliest examples of proportionally long forearms in the theropod fossil records, it still falls in line with the belief that the evolution of flight-capable feathers outpaced the evolution of flight-capable skeletons. The melanosomes, however, are the more intriguing discovery, since they are the earliest examples of “organized platlet-shaped nanostructures…in dinosaurian feathers.”

While paleontologists are confident the Caihong’s platelet structures are melanosomes, the researchers understand that their discovery is based partially on inference and could potentially be incorrect. If the structures aren’t melanosomes, well, that invalidates this entire article. But that’s what paleontology is all about: examining the evidence, creating inferences supported by that evidence, and changing those inferences when new information becomes available. Still, the concept of dinosaurs with iridescent feathers is pretty cool. If you want to learn more about the Caihong juji, you can read the original article on Nature.

Continue Reading

Trending