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For much of the Pliocene and Pleistocene, multiple hominin species coexisted in the same regions of eastern and southern Africa. Due to the limitations of the skeletal fossil record, questions regarding their interspecific interactions remain unanswered. We report the discovery of footprints (~1.5 million years old) from Koobi Fora, Kenya, that provide the first evidence of two different patterns of Pleistocene hominin bipedalism appearing on the same footprint surface. New analyses show that this is observed repeatedly across multiple contemporaneous sites in the eastern Turkana Basin. These data indicate a sympatric relationship between Homo erectus and Paranthropus boisei, suggesting that lake margin habitats were important to both species and highlighting the possible influence of varying levels of coexistence, competition, and niche partitioning in human evolution. [ABSTRACT FROM AUTHOR]

The precise pattern and timing of speciation events that gave rise to all living placental mammals remain controversial. We provide a comprehensive phylogenetic analysis of genetic variation across an alignment of 241 placental mammal genome assemblies, addressing prior concerns regarding limited genomic sampling across species. We compared neutral genome-wide phylogenomic signals using concatenation and coalescent-based approaches, interrogated phylogenetic variation across chromosomes, and analyzed extensive catalogs of structural variants. Interordinal relationships exhibit relatively low rates of phylogenomic conflict across diverse datasets and analytical methods. Conversely, X-chromosome versus autosome conflicts characterize multiple independent clades that radiated during the Cenozoic. Genomic time trees reveal an accumulation of cladogenic events before and immediately after the Cretaceous-Paleogene (K-Pg) boundary, implying important roles for Cretaceous continental vicariance and the K-Pg extinction in the placental radiation.

Massive salt accumulations, or salt giants, have formed in highly restricted marine basins throughout geological history, but their impact on biodiversity has been only patchily studied. The salt giant in the Mediterranean Sea formed as a result of the restriction of its gateway to the Atlantic during the Messinian Salinity Crisis (MSC) 5.97 to 5.33 million years ago. Here, we quantify the biodiversity changes associated with the MSC based on a compilation of the Mediterranean fossil record. We conclude that 86 endemic species of the 2006 pre-MSC marine species survived the crisis, and that the present eastward-decreasing richness gradient in the Mediterranean was established after the MSC. [ABSTRACT FROM AUTHOR]

Heritable variation is a prerequisite for evolutionary change, but the relevance of genetic constraints on macroevolutionary timescales is debated. By using two datasets on fossil and contemporary taxa, we show that evolutionary divergence among populations, and to a lesser extent among species, increases with microevolutionary evolvability. We evaluate and reject several hypotheses to explain this relationship and propose that an effect of evolvability on population and species divergence can be explained by the influence of genetic constraints on the ability of populations to track rapid, stationary environmental fluctuations. [ABSTRACT FROM AUTHOR]

Population size history is essential for studying human evolution. However, ancient population size history during the Pleistocene is notoriously difficult to unravel. In this study, we developed a fast infinitesimal time coalescent process (FitCoal) to circumvent this difficulty and calculated the composite likelihood for present-day human genomic sequences of 3154 individuals. Results showed that human ancestors went through a severe population bottleneck with about 1280 breeding individuals between around 930,000 and 813,000 years ago. The bottleneck lasted for about 117,000 years and brought human ancestors close to extinction. This bottleneck is congruent with a substantial chronological gap in the available African and Eurasian fossil record. Our results provide new insights into our ancestry and suggest a coincident speciation event. [ABSTRACT FROM AUTHOR]

Lateral plant organs, including leaves and reproductive structures, are arranged on stems in distinct patterns termed phyllotaxis. Most extant plants exhibit phyllotactic patterns that are mathematically described by the Fibonacci series. However, it remains unclear what lateral organ arrangements were present in early leafy plants. To investigate this, we quantified phyllotaxis in fossils of the Early Devonian lycopod Asteroxylon mackiei. We report diverse phyllotaxis in leaves, including whorls and spirals. Spirals were all n:(n+1) non-Fibonacci types. We also show that leaves and reproductive structures occurred in the same phyllotactic series, indicating developmental similarities between the organs. Our findings shed light on the long-standing debate about leaf origins and demonstrate the antiquity of non-Fibonacci spirals in plants. [ABSTRACT FROM AUTHOR]

The article discusses the discovery of a fossilized marine worm, Uncus dzaugisi, from over 550 million years ago, pushing back the origin of ecdysozoans, an animal group that includes arthropods, tardigrades, and nematodes—offering evidence of their existence 15 million years before the explosion.

Several scenarios have been proposed to explain rapid net size increases in some early Cenozoic mammalian lineages: sustained and gradual directional change, successive occupation of adaptive zones associated with progressively larger body sizes, and nondirectional evolution associated with branching events in combination with higher diversification potential of the larger lineages. We test these hypotheses in brontotheres, which are among the first radiations of mammals that consistently evolved multitonne sizes. Body-mass evolution in brontotheres mainly occurred during speciation and had no preferential direction. Long-term directional change stemmed from the higher survival of larger lineages in less-saturated herbivore guilds. Our study emphasizes the role of differential species proliferation in explaining the long-term phenotypic trends observed in the fossil record, which are more than an accumulation of steady microevolutionary changes. [ABSTRACT FROM AUTHOR]

Predictions of how marine calcifying organisms will respond to climate change rely heavily on the fossil record of nannoplankton. Declines in calcium carbonate (CaCO3) and nannofossil abundance through several past global warming events have been interpreted as biocalcification crises caused by ocean acidification and related factors. We present a global record of imprint—or “ghost”—nannofossils that contradicts this view, revealing exquisitely preserved nannoplankton throughout an inferred Jurassic biocalcification crisis. Imprints from two further Cretaceous warming events confirm that the fossil records of these intervals have been strongly distorted by CaCO3 dissolution. Although the rapidity of present-day climate change exceeds the temporal resolution of most fossil records, complicating direct comparison with past warming events, our findings demonstrate that nannoplankton were more resilient to past events than traditional fossil evidence suggests. [ABSTRACT FROM AUTHOR]

Mammals are the most encephalized vertebrates, with the largest brains relative to body size. Placental mammals have particularly enlarged brains, with expanded neocortices for sensory integration, the origins of which are unclear. We used computed tomography scans of newly discovered Paleocene fossils to show that contrary to the convention that mammal brains have steadily enlarged over time, early placentals initially decreased their relative brain sizes because body mass increased at a faster rate. Later in the Eocene, multiple crown lineages independently acquired highly encephalized brains through marked growth in sensory regions. We argue that the placental radiation initially emphasized increases in body size as extinction survivors filled vacant niches. Brains eventually became larger as ecosystems saturated and competition intensified. [ABSTRACT FROM AUTHOR]

The article highlights the record sale of the dinosaur species Stegosaurus skeleton "Apex," surpassing previous records, with focus on the implications for research, the buyer's plan to loan it to a U.S. museum, and its exceptional preservation.

The origin of contemporary Europeans remains contentious. We obtained a genome sequence from Kostenki 14 in European Russia dating from 38,700 to 36,200 years ago, one of the oldest fossils of anatomically modern humans from Europe. We find that Kostenki 14 shares a close ancestry with the 24,000-year-old Mal'ta boy from central Siberia, European Mesolithic hunter-gatherers, some contemporary western Siberians, and many Europeans, but not eastern Asians. Additionally, the Kostenki 14 genome shows evidence of shared ancestry with a population basal to all Eurasians that also relates to later European Neolithic farmers. We find that Kostenki 14 contains more Neandertal DNA that is contained in longer tracts than present Europeans. Our findings reveal the timing of divergence of western Eurasians and East Asians to be more than 36,200 years ago and that European genomic structure today dates back to the Upper Paleolithic and derives from a metapopulation that at times stretched from Europe to central Asia.

Molecular time trees indicating that embryophytes originated around 500 million years ago (Ma) during the Cambrian are at odds with the record of fossil plants, which first appear in the mid-Silurian almost 80 million years later. This time gap has been attributed to a missing fossil plant record, but that attribution belies the case for fossil spores. Here, we describe a Tremadocian (Early Ordovician, about 480 Ma) assemblage with elements of both Cambrian and younger embryophyte spores that provides a new level of evolutionary continuity between embryophytes and their algal ancestors. This finding suggests that the molecular phylogenetic signal retains a latent evolutionary history of the acquisition of the embryophytic developmental genome, a history that perhaps began during Ediacaran-Cambrian time but was not completed until the mid-Silurian (about 430 Ma). [ABSTRACT FROM AUTHOR]

The profitability and sustainability of future biorefineries are dependent on efficient feedstock use. Therefore, it is essential to valorize lignin when using wood. We have developed an integrated biorefinery that converts 78 weight % (wt %) of birch into xylochemicals. Reductive catalytic fractionation of the wood produces a carbohydrate pulp amenable to bioethanol production and a lignin oil. After extraction of the lignin oil, the crude, unseparated mixture of phenolic monomers is catalytically funneled into 20 wt % of phenol and 9 wt % of propylene (on the basis of lignin weight) by gas-phase hydroprocessing and dealkylation; the residual phenolic oligomers (30 wt %) are used in printing ink as replacements for controversial para-nonylphenol. A techno-economic analysis predicts an economically competitive production process, and a life-cycle assessment estimates a lower carbon dioxide footprint relative to that of fossil-based production. [ABSTRACT FROM AUTHOR]

The article focuses on the donation of over 1000 fossils to the National Museum of Brazil to aid in the reconstruction of its paleontology collection after a devastating fire in 2018, with the specimens originating from Brazil's Araripe Basin, showcasing remarkable preservation of soft tissue.

The article focuses on a study revealing that the rise of flowering plants led to the demise of early ant species while allowing modern ants to diversify and thrive by doubling the available nutrients, with the transition coinciding with the rapid diversification of ants into thousands of species.

The article focuses on genetic analyses suggesting that an ancient human population suffered a severe bottleneck around 930,000 years ago. Topics discussed include the potential correlation between this bottleneck and the evolution of a new human species, the last common ancestor of Homo sapiens, Neanderthals, and Denisovans, and the need for further research to test these hypotheses against fossil and archaeological evidence.

The widespread extinctions of large mammals at the end of the Pleistocene epoch have often been attributed to the depredations of humans; here we present genetic evidence that questions this assumption. We used ancient DNA and Bayesian techniques to reconstruct a detailed genetic history of bison throughout the late Pleistocene and Holocene epochs. Our analyses depict a large diverse population living throughout Beringia until around 37,000 years before the present, when the population's genetic diversity began to decline dramatically. The timing of this decline correlates with environmental changes associated with the onset of the last glacial cycle, whereas archaeological evidence does not support the presence of large populations of humans in Eastern Beringia until more than 15,000 years later.

The relative merits of molecular and paleontological dates of major branching points in the tree of life are currently debated. In some cases, molecular date estimates are up to twice as old as paleontological dates. However, although it is true that paleontological dates are often too young (missing fossils), molecular dates are often too old (statistical bias). Intense study of the dating of major splits in the tree of mammals has shown rapprochement as fossil dates become older and molecular dates become younger.

The article focuses on a discovered 350-million-year-old tree fossil named Sanfordiacaulis densifolia found in Canada, offering insights into early tree species with a distinctive crown of spiky leaves and mentions that the findings were published in the journal "Current Biology" in February 2024.

It has been proposed that modern humans descended from a single woman, the "mitochondrial Eve" who lived in Africa 100,000 to 200,000 years ago. The human immune system DRB1 genes are extremely polymorphic, with gene lineages that coalesce into an ancestor who lived around 60 million years ago, a time before the divergence of the apes from the Old World monkeys. The theory of gene coalescence suggests that, throughout the last 60 million years, human ancestral populations had an effective size of 100,000 individuals or greater. Molecular evolution data favor the African origin of modern humans, but the weight of the evidence is against a population bottleneck before their emergence. The mitochondrial Eve hypothesis emanates from a confusion between gene genealogies and individual genealogies.

This article discusses new fossil discoveries dating from the Cambrian Period, an era in which the earth experienced an abundance of complex life about 540 million years ago. The author comments on this period as the provenance of nearly all modern life and examines the research being conducted in the region known as the Burgess Shale in the Canadian Rockies, discovered in 1909 by paleontologist Charles Doolittle Walcott, as well as other fossil-rich sites in the Rocky Mountain region.

The article discusses a study in which fossils and inferred homology patterns were used to determine the evolutionary history of the mammalian regionalized spine.

Until now, all known fossils of tetrapods (limbed vertebrates with digits) and near-tetrapods (such as Elpistostege, Tiktaalik, and Panderichthys) from the Devonian period have come from localities in tropical to subtropical paleolatitudes. Most are from Laurussia, a continent incorporating Europe, Greenland, and North America, with only one body fossil and one footprint locality from Australia representing the southern supercontinent Gondwana. Here we describe two previously unknown tetrapods from the Late Devonian (late Famennian) Gondwana locality of Waterloo Farm in South Africa, then located within the Antarctic Circle, which demonstrate that Devonian tetrapods were not restricted to warm environments and suggest that they may have been global in distribution. [ABSTRACT FROM AUTHOR]

To date, the earliest modern human fossils found outside of Africa are dated to around 90,000 to 120,000 years ago at the Levantine sites of Skhul and Qafzeh. A maxilla and associated dentition recently discovered at Misliya Cave, Israel, was dated to 177,000 to 194,000 years ago, suggesting that members of the Homo sapiens clade left Africa earlier than previously thought. This finding changes our view on modern human dispersal and is consistent with recent genetic studies, which have posited the possibility of an earlier dispersal of Homo sapiens around 220,000 years ago. The Misliya maxilla is associated with full-fledged Levallois technology in the Levant, suggesting that the emergence of this technology is linked to the appearance of Homo sapiens in the region, as has been documented in Africa. [ABSTRACT FROM AUTHOR]

The remnant of the spinosaurid's skull was discovered in Brazil and purchased from a fossil digger by the State Museum of Natural History Stuttgart in 1991; researchers used it to describe the species in a 1996 paper. Paleontologists from Brazil and Europe have published an open letter asking the German state of Baden-Württemberg to return a fossil of the dinosaur Irritator challengeri (illustration above) to Brazil. Call for fossil's return to Brazil. [Extracted from the article]

The article discusses about the project of Jasmina Wiemann and Derek Briggs, Yale University's Peabody Museum of Natural History on finding the way to extract information captured in degraded proteins, even in fossils hundreds of millions of years old and nondestructive technique of focusing the laser on specimens to expose the ancient chemical bonds for explaining the paleontological mysteries.

The article discusses cellular details of gill arches in Cambrian fossils and discovery of fishlike forms known as yunnanozoans in the Yunnan province of China. It informs that Wielding scanning electron microscopy reveals cellular and subcellular structures of the skeletal bars that best compare to cartilaginous gill arches of modern vertebrates. It mentions that among other Cambrian fishlike forms, Haikouichthys seems to have skeletal rods that support the gills.

The article presents the discussion on deep carbon exhuming by volcanic rift between Greenland and Europe. Topics include researchers invoking exotic mechanisms such as catastrophic releases of methane from the sea floor or even asteroid strikes; and fossil records showing trees migrated uphill and to higher latitudes.

Researchers had thought those ancestors had replaced the Cambrian creatures, but the new site - a small quarry in a sheep field - shows a much more gradual transition, say Joe Botting and Lucy Muir of Amgueddfa Cymru-National Museum Wales. Among a bonanza of fossils, the married duo has cataloged 170 marine species, including glass sponges, crustaceans called horseshoe crab shrimp, and a six-legged arthropod that may have given rise to insects. PALEONTOLOGY | In Wales, paleontologists have uncovered a rich source of 462-million-year-old fossils that reveal more overlap than expected between animals that evolved during the Cambrian Explosion 40 million years earlier and the ancestors of modern species. [Extracted from the article]

The article discusses the study published in the journal "Science" on the challenges of the traditional view of ape origins and suggests that early apes evolved their upright torsos and acrobatic climbing abilities not to reach ripe fruit in the terminal branches. The study utilized paleontological evidence from the Moroto II site in Uganda to analyze the functional anatomy of ape fossils and reconstruct the paleoecology of the environment.

The article informs that according to a study published in the journal "Papers in Paleontology," researchers have discovered a large deposit of well-preserved sea anemone fossils in northern Illinois's Mazon Creek deposit.

The article presents information on a conference on studies on hominins held in Tbilisi and at the site of preserved fossils of hominins in Dmanisi, Georgia from September 20 to 24, 2016. Topics discussed during the conference include the life of these hominins, their health, struggles and survival.

This article discusses the evolution of Homo sapiens based on genetic and fossil information. The authors comment on the shared characteristics of Homo sapiens, including large brains, narrow pelvises, and smaller teeth, in comparison to other members of the genus Homo, such as Neanderthals and Denisovans. Advances in the understanding of the human fossil record are also explored.

The article focuses on analysis by researchers working in Kromdraai Cave on publishing description of fossils of Homo, and mentions histories and relationships of hominin species to be revealed by the study.

The article presents the discussion on dinosaurs in spring according to a study of fish fossils excavated in North Dakota showing season of the Cretaceous-Paleogene mass extinction.

The article presents the discussion on fossil records from tropical oceans predicting biodiversity loss. Topics include small changes in seawater temperature, acidity, or oxygen content having substantial impacts on the marine biota; and intraspecific adaptation maintaining aerobic balance in a warmer and lower oxygen environment.

The article presents the author's response to comments about their article "Whole-genome analyses resolve early branches in the tree of life of modern birds." The comments were presented by K. J. Mitchell and others in this issue. A point of dispute is the dating of modern birds in the avian phylogeny. The study authors contend that most modern bird orders diverged prior to the Cretaceous-Paleogene mass extinction event, which happened 66 million years ago and that Mitchell and others incorrectly interpreted the fossil data used in the study.

The article focuses on research using the fossil record to provide information on past extinctions to help predict biotic responses. It states that geographic range size and taxonomic membership consistently explains a significant proportion of extinction risk variation in six taxonomic groups. It assesses the intrinsic risk of extinction for modern genera and identifies coastal biogeographic provinces where human activity or climatic changes strongly affect fauna with high intrinsic risk.

The article discusses research, led by paleontologist Robert DePalma and presented at the 2021 meeting of the Geological Society of America, that suggests dinosaurs were witnesses to the asteroid that ushered them out of extinction. DePalma and his colleagues found evidence at a fossil-rich site in North Dakota called Tanis. Many paleontologists were skeptical, but geophysicist Sean Gulick believes the study shows a healthy ecosystem in the Dinosauria prior to the extinction.