Naturwissenschaften

Magnon, Valentin; Corbara, Bruno

doi: 10.1007/s00114-022-01814-9pmid: 35960360

Since Darwin’s theory of evolution, adaptationism is frequently invoked to explain cognition and cultural processes. Adaptationism can be described as a prescriptive view, as phenotypes that do not optimize fitness should not be selected by natural selection. From an epistemological perspective, the principle of a prescriptive definition of adaptation seems incompatible with recent advances in epigenetics, evolutionary developmental biology, ethology, and genomics. From these challenges, a proscriptive view of adaptation has emerged, postulating that phenotypes that are not deleterious will be evolutionary maintained. In this epistemological investigation, we examine how the shift from adaptationism to a proscriptive view changes our view of cognition and culture. We argue that, while adaptationism leads to cognitivism and a view of culture as strategies to optimize overall fitness, the proscriptive definition favors embodied theories of cognition and a view of culture as the cumulative diffusion of behaviors allowed by the constraints of reproduction.

Costa-Leonardo, Ana Maria; Janei, Vanelize; da Silva, Iago Bueno

doi: 10.1007/s00114-022-01815-8pmid: 35980473

Insects and fungi are abundant in many environments, in which facultative and/or obligate associations involving these groups have been established during evolution. In termites, mutualism with fungi is well reported for some termite lineages (e.g., Macrotermitinae). Within some subterranean termite species (Rhinotermitidae), egg-mimicking fungi, also referred to as “termite “balls”, are often harbored inside the nest, mixed to the egg piles. Such interaction seems to be advantageous for both partners since the fungi are protected inside the nest while they may serve as an additional food source and also provide cellulases which may be incorporated into the termite digestive process. Although such mutualism has been reported for seven species of Reticulitermes and Coptotermes formosanus, all the samplings were restricted to temperate regions. Here, we provide the first Neotropical record of this termite-fungus association, and the first report for Coptotermes gestroi. The morphological characters of the “termite balls” observed in a C. gestroi nest resemble those already reported for Reticulitermes spp. and the congeneric species C. formosanus. They include a color ranging from light to dark brown, spherical shape, and a reduced diameter (0.23–0.34 mm). Our findings provide new insights into the geographical distribution of the association between termites and sclerotium-forming fungi. Future genetic analyses will be valuable aiming to identify the egg-mimicking fungi associated with C. gestroi and shed light on the evolution of this fascinating symbiosis.

de Lima, Jessica Ferreira; Moreira, Ana Silvia Franco Pinheiro

doi: 10.1007/s00114-022-01816-7pmid: 35997846

The aerial environment appears to structurally modify roots, which frequently show specializations for absorbing water and nutrients. Among those specializations are the velamen, a multiseriate epidermis generally composed of dead mature cells, and greater degrees of lignification in the endodermis, exodermis, and pith. Vanilla phaeantha is a hemiepiphyte used here as a model of study to determine which root characteristics demonstrate the most plasticity in response to aerial and terrestrial environments. It produces roots growing under three conditions: (1) aerial and free, growing from the highest branches towards the ground; (2) aerial roots attached to the phorophyte; and (3) terrestrial. Samples taken 3 cm from the apices were used to prepare histological slides. The tissues and other anatomical structures were measured and histochemically characterized. The most plastic characteristics were the external periclinal thicknesses of the exodermis and the total area occupied by the aerenchyma lacunae. The free roots were the longest, did not evidence root hairs, and had the largest number of the aerenchyma lacunae; they also evidenced greater thicknesses of the exodermis in contact with the epidermis walls that helped maintain their shapes. Terrestrial roots had root hairs around the entire circumference and intense infestations of mycorrhiza, indicating their involvement in nutrient acquisition. The adhering roots evidenced free regions similar to those of aerial roots, as well as adhering regions showed characteristics similar to terrestrial roots (with root hairs and mycorrhiza infestations).

McCarren, Sam; Midgley, Jeremy J.; Johnson, Steven D.

doi: 10.1007/s00114-022-01817-6pmid: 36029364

The function of flower orientation is much debated, with adaptation to pollinator mouthparts being a particularly compelling explanation, but also one that has lacked empirical support from broad-scale comparative studies. The two families of long-proboscid fly pollinators show similar hovering behaviour while feeding on nectar but differ in the biomechanics of their proboscides which can be up to 80 mm in length: Tabanidae have a fixed forward-pointing proboscis while Nemestrinidae can swivel their proboscis downwards. We predicted that this difference has implications for the evolution of flower orientation. We established the flower angles of 156 South African plant species specialised for pollination by long-proboscid flies. Using a phylogenetically corrected analysis, we found that flowers pollinated by Tabanidae tend to be horizontally orientated, while those pollinated by Nemestrinidae tend to be more variable in orientation and more often vertically orientated. These results confirm the importance of pollinator biomechanics for the evolution of floral traits and highlight a potential mechanism of reproductive isolation between sympatric plant species pollinated by different long-proboscid fly families.

Furuichi, Sho; Kamimura, Yasuhiro; Suzuki, Masahiro; Yukami, Ryuji

doi: 10.1007/s00114-022-01819-4pmid: 36125549

Many small pelagic fishes obligately form schools; some of these schools reach remarkable sizes. Although the school is a fundamental and important ecological unit and is the site of biological interactions such as competition and predation, information on schooling processes in the field remains scarce. Here, we examined the quantitative relationships between population density and school size, the number of schools, and other school characteristics (i.e. packing density, volume, and cross-sectional area) in three species of small pelagic fishes: Japanese anchovy Engraulis japonicus, Japanese sardine Sardinops melanostictus, and chub mackerel Scomber japonicus. We found that school size increased almost linearly with population density, whereas the number of schools and other characteristics increased non-linearly with population density, whereby the rate of increase slowed radically as population density increased. These results indicate that, at low population densities, an increase in density causes an increase in both school size and the number of schools, whereas at higher population densities, an increase in density triggers the formation of larger schools rather than more schools. Furthermore, we found that the shapes of the relationships of all school characteristics with population density differed amongst species. Our results indicate that the schooling behaviour of small pelagic fishes is density-dependent, and responses to changes in density are species-specific. Our results provide insight into how biological interactions such as intra- and inter-specific competition and predator–prey interactions mediate the density-dependent processes that underlie the population dynamics and community structure of small pelagic fishes in marine ecosystems.

Kernan, Ciara E.; Yiambilis, A. N.; Searcy, Z. E.; Pulica, R. M.; Page, R. A.; Caldwell, M. S.

doi: 10.1007/s00114-022-01813-wpmid: 35969288

While foraging, eavesdropping predators home in on the signals of their prey. Many prey signal from aggregations, however, and predators already en route to attack one individual often encounter the signals of other prey. Few studies have examined whether eavesdropping predators update their foraging decisions by switching to target these more recently signaling prey. Switching could result in reduced localization errors and more current estimates of prey location. Conversely, assessing new cues while already in pursuit of another target might confuse or distract a predator. We tested whether fringed-lipped bats (Trachops cirrhosus) switch prey targets when presented with new cues mid-approach and examined how switching and the distance between simulated prey influence attack accuracy, latency, and prey capture success. During nearly 80% of attack flights, bats switched between túngara frog (Engystomops pustulosus) calls spaced 1 m apart, and switching resulted in lower localization errors. The switching rate was reduced, and the localization advantage disappeared for calls separated by 3 m. Regardless of whether bats switched targets, attacks were less accurate, took longer, and were less often successful when calls were spaced at larger distances, indicating a distraction effect. These results reveal that fringed-lipped bats attend to cues from non-targeted prey during attack flights and that the distance between prey alters the effectiveness of attacks, regardless of whether a bat switches targets. Understanding how eavesdropping predators integrate new signals from neighboring prey into their foraging decisions will lead to a fuller picture of the ways unintended receivers shape the evolution of signaling behavior.

Gueguen, Léa; Lerch, Noémie; Grandgeorge, Marine; Hausberger, Martine

doi: 10.1007/s00114-022-01811-ypmid: 35951112

Tactile perception is involved in a variety of contexts (adaptations to climatic conditions, protection of the body against external dangers…) and is as important as the other sensory modalities for the survival of an individual. This tactile modality has been particularly well studied in humans, revealing high individual variations modulated by a variety of intrinsic and extrinsic factors such as age, sex, pathological disorders, or temperament. Tactility is also involved in animals’ social lives, although there are disparities between species. For example, social tactile contact among horses is limited, but this does not mean that they do not react to tactile stimuli but rather with their very thin skin they are able to detect minute stimuli (although they respond more to larger stimuli). Despite a fairly large effort to characterize it, there are controversies concerning equine tactile sensitivity. In this review, we examine studies that have used the same tool (von Frey filaments) and try to disentangle what could explain the differences observed. It appears that many aspects are poorly known or controversial and that the procedures may be so different that the results of different studies cannot be compared. We went further by testing tactile reactivity of a population of unridden horses and found that four factors influenced their tactile reactivity (type of horse, filament size, body area, time of day). These results could explain some of the discrepancies observed in the literature and suggest, in particular, that more attention should be paid to the context of the test.

Schumm, Yvonne R.; Masello, Juan F.; Cohou, Valerie; Mourguiart, Philippe; Metzger, Benjamin; Rösner, Sascha; Quillfeldt, Petra

doi: 10.1007/s00114-022-01812-xpmid: 35976443

Migration is used by many species as a strategy to deal with a seasonally changing environment. For some species, migration patterns can vary across different or even within the same breeding area. The Common Woodpigeon Columba palumbus, an abundant and widespread Palearctic species, exhibits three migratory strategies (strictly migratory, partially migratory and resident) across its European breeding grounds. Based on ring recoveries and satellite tracking data, we investigated the migration and foraging behaviour of Woodpigeons breeding in Southwestern Europe (Portugal) and Central Europe (Germany). We found that individuals could be classified as residents (Portugal) or partial migrants (Germany), with migrating individuals following the European sector of the East Atlantic flyway, and mainly wintering in France. In addition to general data on migration phenology, we provide evidence for different migration strategies (migration of varying distances or resident behaviour), low wintering site fidelity and the use of multiple wintering sites. Furthermore, tracking data provided information on migratory behaviour in consecutive years, clearly showing that individuals may switch migratory strategies (resident vs. migrant) between years, i.e. are facultative partial migrants. While individuals from Portugal mainly stayed within a large park (‘green urban area’) year-round, Woodpigeons from the city of Giessen (Germany) regularly left the urban area to forage on surrounding farmland (with an average distance covered of 5.7 km), particularly from July to September. Overall, our results highlight the behavioural plasticity in Woodpigeons in terms of foraging and migration strategies within and amongst individuals as well as populations.

Vera, Bárbara; Folino, Micaela; Soechting, Walter; Böttcher, Nicole

doi: 10.1007/s00114-022-01810-zpmid: 35939154

Pyrotheria is one of the most peculiar orders of South American native ungulates, whose members evolved from the early? Eocene to the late Oligocene period when they became extinct. Here, we described the most complete specimen of Propyrotherium saxeum ever found, one of the lesser-known representatives of pyrotheres that characterized the middle-late Eocene period of Patagonia (Argentina). It includes a nearly complete mandible and a tusk-like tooth of the same individual, as well as other isolated upper and lower teeth. Propyrotherium saxeum has a dental formula that includes at least P2–M3 and i2?–p3–m3 (lack of p2). It is characterized by some peculiar features of the mandible (e.g., ascending ramus longer than high, hiding the m3 and straight incisura mandibular) and dentition (e.g., cristid obliqua in p3–m3, cristid between posterior lophid and distal cingulid in m1–m3, P3–M3 and p3–m3 bilophodont, P2 and p3–m3 bi-rooted, P3–M3 three-rooted, paraconid in p3). The phylogenetic analysis reveals that Propyrotherium is more closely related to Pyrotherium and Baguatherium, differing from the previous hypothesis, and supports the monophyly of Pyrotheriidae including Carolozittelia, Griphodon, Pyrotherium, Baguatherium, and Propyrotherium. The absolute age obtained through U–Pb zircon dating of the Sarmiento Formation at Cañadón Pelado, the fossil’s original locality, indicates that the fossil-bearing tuff would have been deposited between 39.65 and 40.41 Ma, with a weighted mean age of 40.03 ± 0.38 Ma (Bartonian). This implies a biochron much longer than previously thought for Propyrotherium and provides a chronological framework for the fauna of Cañadón Pelado.

Garvie, Laurence A. J.

doi: 10.1007/s00114-022-01818-5pmid: 36056972

Ikaite is the calcium carbonate hexahydrate (CaCO3·6H2O), which precipitates below ~ 7 °C, first identified from Ikka Fjord in southwest Greenland and subsequently more widely reported. Here is described the serendipitous discovery of ikaite on a tree (Populus fremontii) wound from the hot Sonoran Desert, which precipitates during short cold periods in the winter, whereas monohydrocalcite forms through most of the year. The tree wound consists of infected wood, called wetwood that exudes a nutrient-rich water on which a jelly-like slime flux forms. Ikaite, along with alpha sulfur, precipitates in and on the bacterial slime flux jelly. Each tree wound occurs as an island of mineralization: all the elements for the mineral formation are supplied through the xylem sap expressed from the wetwood infection. The P. fremontii wetwood is capped and surrounded by a hard mineralized zone dominated by ikaite/monohydrocalcite, alpha sulfur, and a range of carbonates and sulfates, on which the slime flux jelly occurs. Water oozing from the wetwood is modestly alkaline (pH = 8.34), with elevated concentrations of K+ (5554.7 ppm) and S as SO42− (1662.9 ppm), with Ca2+ (151.9 ppm) and Mg2+ (270.3 ppm). This water chemistry favors the precipitation of ikaite/monohydrocalcite, both within and below the jelly. The ikaite is temperature sensitive, though the laboratory results show that it can persist for several days at room temperature in the sulfur-rich jelly. The ikaite, and associated mineralization within and around the slime flux jelly, illustrates a new, and likely, global form of bio-mediated mineralization.