“…S22). Overall, the observed pattern is congruent with phenotypic evolution being mostly condensed in events of peripatric speciation (17,18), where phenotypic sorting through drift or adaptation to immediate conditions is geologically rapid (28), and decoupled in direction from macroevolutionary trends (19). The signal of this discontinuity is also demonstrated by the weak reconstructed trend and attraction parameters in our phylogenetic models [trend parameter (m) = 0 and attraction parameter (a) = 0.002, respectively; table S2].…”
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.
“…S22). Overall, the observed pattern is congruent with phenotypic evolution being mostly condensed in events of peripatric speciation (17,18), where phenotypic sorting through drift or adaptation to immediate conditions is geologically rapid (28), and decoupled in direction from macroevolutionary trends (19). The signal of this discontinuity is also demonstrated by the weak reconstructed trend and attraction parameters in our phylogenetic models [trend parameter (m) = 0 and attraction parameter (a) = 0.002, respectively; table S2].…”
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.
“…Figure 1Fossil sites of P. antiquus , P. cf. mnaidriensis and Chinese Palaeoloxodon [9,13,17]. The map draft (chart no.…”
Section: Methodsmentioning
confidence: 99%
“…After appearing in Eurasia around 0.78 million years ago (Ma) [5], Palaeoloxodon likely diversified into several species, including P. antiquus , P. huaihoensis , P. namadicus and P. naumanni in mainland Eurasia [6,7], as well as some dwarf species inhabiting the Mediterranean islands, such as P. cf. mnaidriensis [8,9]. Palaeoloxodon in Europe became extinct around 34 thousand years ago (Ka) [10], while its extinction time in China is in need of re-evaluation owing to insufficient direct dating information, although a suggestive lower limit is the end of the Late Pleistocene [11,12].…”
Straight-tusked elephants (genus:
Palaeoloxodon
) including their island dwarf forms are extinct enigmatic members of the Pleistocene megafauna and the most common Pleistocene elephants after the mammoths. Their taxonomic placement has been revised several times. Using palaeogenomic evidence, previous studies suggested that the European
P. antiquus
has a hybrid origin, but no molecular data have been retrieved from their Asian counterparts, leaving a gap in our knowledge of the global phylogeography and population dynamics of
Palaeoloxodon
. Here, we captured a high-quality complete mitogenome from a Pleistocene Elephantidae molar (CADG841) from Northern China, which was previously morphologically assigned to the genus
Elephas
(Asian elephant), and partial mitochondrial sequences (838 bp) of another
Palaeoloxodon
sp
.
specimen (CADG1074) from Northeastern China. We found that both Chinese specimens cluster with a 244 000-year-old
P. antiquus
(specimen name: WE) from Western Europe, suggesting that this clade may represent a population with a large spatial span across Eurasia. Based on the fossil record and the molecular dating of both the divergences of different
Palaeoloxodon
mitochondrial clades and previously determined hybridization events, we propose that this Eurasian-wide WE clade provides evidence for an earlier migration and/or another hybridization event that happened in the evolutionary history of straight-tusked elephants.
“…Tooth enamel is highly mineralized, which bodes well for IcP preservation but proved particularly challenging for AA analyses; the high concentrations of inorganic salts in this calcium phosphate biomineral limited accurate quantification ( 105 ). Development of a new biphasic preparation method, tested first on elephantid tooth enamel ( 79 , 106 ), shows that the rates of the reactions are significantly slower than those of calcium carbonate biominerals, which extends the time range of the enamel intracrystalline protein degradation (IcPD) method in temperate latitudes into the Pliocene. This technique has also been useful for testing the integrity of fossil protein in paleoproteomic studies, confirming the endogeneity of 1.78 Ma protein from rhino enamel from the Paleolithic site of Dmanisi ( 107 ) and demonstrating the enormous potential for the preserved protein in mammalian tooth enamel to provide evolutionary relationships on directly dated samples.…”
Despite the vast array of different geochronological tools available, dating the Paleolithic remains one of the discipline’s greatest challenges. This review focuses on two different dating approaches: trapped charge and amino acid geochronology. While differing in their fundamental principles, both exploit time-dependent changes in signals found within crystals to generate a chronology for the material dated and hence, the associated deposits. Within each method, there is a diverse range of signals that can be analyzed, each covering different time ranges, applicable to different materials and suitable for different paleoenvironmental and archaeological contexts. This multiplicity of signals can at first sight appear confusing, but it is a fundamental strength of the techniques, allowing internal checks for consistency and providing more information than simply a chronology. For each technique, we present an overview of the basis for the time-dependent signals and the types of material that can be analyzed, with examples of their archaeological application, as well as their future potential.
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