Ecology and Evolutionary Biology

NOSSO CENÁRIO

Vivemos a época do Holoceno que teve seu início com o fim da última era glacial principal, ou Idade do Gelo.

Em grego, Holoceno significa “tudo recente”, sendo a atual época, do período Quaternário que abrange os últimos 11.800 anos. Nesta época, que ocorreu o derretimento do gelo, causando a elevação do nível do mar em 35 metros - acima dos 120 metros de outra elevação ocorrida há 20 mil anos atrás.

Essas elevações do nível do mar fizeram com que Japão, Indonésia e Taiwan se separassem da Ásia, a Grã-Bretanha se separasse da Europa Continental, Nova Guiné e Tasmânia se separassem da Austrália. Além disto, formou-se o estreito de Bering, com 85 quilômetros de comprimento e 30 a 50 metros de profundidade o que havia sido uma ponte gelada durante a Idade do Gelo, por onde, possivelmente, o homem migrou para o continente americano. Acredita-se que a única espécie humana que tenha vivido no Holoceno seja o Homo sapiens que nos últimos 5.mil anos vem desenvolvendo agricultura, pecuária e criando grandes conglomerados urbanos. Posteriormante, desenvolveu a revolução industrial, e mais recentemente, a cibernética, causando modificações na estrutura e no funcionamento da superfície do planeta Terra, bem como o no nosso modo de produzir bens de consumo e conhecimento. A situação é tão peculiar que alguns cientistas adotaram o termo Antropoceno para designar a época geológica caracterizada pela irresponsável intervenção humana nos processos naturais ocorrida nos últimos 300 anos.

Entretanto, as alterações planetárias e a diversidade de ambientes e variações de ciclos climáticos foram e são bem mais extremadas do que vivemos nos dias de hoje, haja vista as alterações geológicas e as grades extinções em massa registradas nas camadas de rochas e nos depósitos de fósseis de animais, vegetais e microrganismos. Os frutos dessas alterações geológicas e climáticas são as variedades de ambientes e a grande biodiversidade em nosso planeta.


2 - AMBIENTES EXTREMADOS

Muitas vezes, as condições ambientais de certos lugares fogem ao padrão mediano, sendo, portanto, caracterizado como ambientes extremados. A seguir estão listados os locais mais extremados do planeta Terra em termos físicos e químicos:
a) O lugar mais quente da Terra é o Deserto de Lut, no Irã, onde foi registrada a temperatura máxima de 71⁰C.
b) O lugar mais frio e habitado é Oymyakon, na Rússia, onde foi registrada a temperatura - 72⁰C.
c) O ponto mais alto em relação ao centro da Terra é o Monte Chimborazo, no Equador, que dista em 6.384,4 quilômetros do centro da Terra superando o Everest com 6.382,6 quilômetros do centro da Terra, o que dá uma diferença de 1.811 metros.
d) A maior cachoeira do mundo fica em Santo Ángel, na Venezuela - começa a 984 metros de altura, com queda ininterrupta de 806 metros.
e) O lugar mais seco da Terra fica nos Vales da Morte, na Antártica, sem chuva há mais de dois bilhões de anos - e ventos de até 320 quilômetros por hora, evaporando toda a água existente, sendo o único local da Antártica que não possui gelo.
f) O lugar mais úmido fica em Lloro, na Colômbia: recebe a média de 12 mil metros cúbicos de chuva por ano. Entre agosto de 1860 e julho de 1861, o local teve um registro de chuva de 26 mil.milímetros
g) O lugar mais abaixo do nível do mar é o Mar Morto, na Jordânia. Fica a 422 metros abaixo do nível do mar.
h) O ponto mais profundo do planeta é a Fossa das Marianas: entre a Indonésia e o Japão. Possui 10.924 metros abaixo do nível do mar e que confere oito toneladas de pressão.
i) O lago mais quente do mundo é o Boling Lake que fica na República Dominica cuja a água atinge 90⁰C.
j) O lugar que possui a maior formação rochosa do mundo e a mais pontiagudas fica em “tsingy”, que, significa “lugar onde não se anda descalço” fica no parque chamdo Bemaraha National Park em Madagascar. Ele é composto por uma formação rochosa de pedras de 100 metros de altura e extremamente cortantes que forma moldadas por chuvas tropicais.

A contribuição humana para essa lista está na concentração de poluentes radioativos e químicos em diferentes partes do mundo devido a industrialização e produção de armamentos e nas exótica contrução do Jardim Veneniso de Alnwick que se encontra na Inglaterra localizado na propriedade da duquesa Jarry Percy que custou cerca de R$ 120 milhões e que congrega mais de 100 espécies de plantas venenosas ou possuidoras de narcótiocos que por vezes podem matar uma pessoa que simplesmente tocá-las.
A Cooperativa Química de Mailuu-Suu localizada no Quirguistão é um dos lugares mais poluídos do mundo, no qual a radiação não vem de bombas nucleares, mas da mineração de urânio em larga escala, bem como das atividades de processamento que foram realizadas na região onde existe quase 2 milhões de metros cúbicos de lixo poluente na área.
No Brasil foi possível verificar como uma população e toda a biota ao seu redor sobrevive às altas doses de radiação natural. O cenário estudado foi o Morro do Ferro localizado em Poços de Caldas no interior do Estado de Minas Gerais. Nesse lugar, a intensidade gerada pelo decaimento radioativo do Tório naturalmente acumulado em uma área de 30 mil metros quadrados atinge níveis de 100 a 300 vezes o limite natural e considerado normal. Além do Tório que soma cerca de 30 mil toneladas, esse lugar tem cerca de 100 toneladas de Urânio e 50 mil toneladas de elementos da séria química chamada de Terras Raras. Os efeitos biológicos dessas condições são mensuráveis na urina e fios de cabelos da população local através da dosagem de radionucídeos.
Como os organismos se encaixam nesses e em outros extremos? O que separa, em termos geológicos e biológicos, os microrganismos dos seres mais complexos como os mamíferos? Como os seres interagem entre si para acompanhar tantas mudanças e diversidades? Como aproveitam todas as infinitas possibilidades para co-evoluir e persistir?

Nesse contexto, propus à alguns colegas do Instituto de Biologia da Universidade Federal Fluminense, embargar a jornada de escrever um livro intitulado: Biologia quase ao extremo. Obra esssa que abordasse alguns dos muitos exemplos de “esquisitices biológicas”, isto é, existências, processos e organismos biológicos que “parecem” fugir do corriqueiro, mas que nem sempre chegam ao extremo.

Como é intrigante a existência de bactérias que são chamadas de termófilas porque que vivem em ambientes inóspitos para a grande maioria das espécies tais como ecossistemas no entorno de fendas vulcânicas e falhas nas crostas marinhas, resistindo a temperaturas entre 75⁰C e 100⁰C. Elas realizam quimiossíntese, utilizando compostos inorgânicos (ácido sulfídrico – H2S) para sintetizar matéria orgânica, obter energia e apresentam características peculiares em sua membrana.

Em ambientes extremamente anaeróbicos, isto é, sem oxigênio, as bactérias metanogênica utilizam o hidrogênio como cofator (substâncias orgânicas ou inorgânicas necessárias ao funcionamento das enzimas) que são responsáveis por reações que catabolizam o gás carbono (CO2) em metano (CH4).

Nos ambientes com altas concentrações de sal reinam as bactérias halófitas e existem plantas que suportam este tipo de condição como o caso de árvores de manguezais. A resistência à salinidade - por plantas halófitas - pode ocorrer através da acumulação de cloreto de sódio dentro do vacúolo ou por resistência à entrada de cloreto de sódio na célula e por diluição de cloreto de sódio após sua entrada na planta. Uma característica bioquímica da adaptação das plantas à salinidade é a acumulação de duas substâncias nitrogenadas chamadas de prolina e glicinobetaína.

Com relação à baixas temperaturas tem-se o peixe do gelo que produz proteínas anti-congelantes. Por outro lado, os insetos conseguem desenvolver tolerância a temperaturas abaixo de zero através da síntese de glicerina, que age como um anticongelante, da mesma forma que o etilenoglicol age no radiador dos carros resfriados a água.

Nas plantas superiores, a adaptação ao gelo parece ser bem mais complexa que nos peixes do gelo, mas sempre se faz uma correlação da tolerância ao frio com o aumento do teor de açúcar na seiva. A capacidade de resistir à geada pode ser induzida artificialmente em plantas com a injeção de solução com açúcares. Os açúcares encontrados nas plantas - que são naturalmente resistentes ao congelamento (glicose, frutose e sacarose) - variam de planta para planta dependendo da idade e espécie envolvida.

Nesse livro, a história do peixe do gelo encontra-se no Capítulo 7. Os seis capítulos que antecedem a esse tratam de temas sobre a importância biológica de espécies invasoras, de espécies de microrganismos que habita o corpo humano, de espécies de poliquetas que vivem em diferentes condições, de espécies canibais e de espécies de parasitos de crias, isto é que deixam seus ovos sob cuidado de outros pais.

"In January 2008 the world’s leading scientific journal, Nature, carried an editorial titled “Spread the Word: Evolution is a scientific fact, and every organization whose research depends on it should explain why”.  Speaking for the world of science, Nature publically established evolution as a fact, in black and white, and called on educators worldwide to teach it such.

This popular-science book will walk the reader through the evolutionary process, using plenty of real-world examples to make it crystal clear that evolution does indeed occur.

My focus is on dispelling the common conception of evolution as a sort of noun; a sort of ‘thing’ that produces finished life forms; a unified, intentional process with a kind of ‘itness’.

Rather, I show that evolution is a word we use to characterize the unintended consequences of three independent facts of the natural world; the fact that life forms come from parent generations (replication), the fact that offspring are not identical (variation), and the fact that not all offspring survive to pass their genes on to the next generation (selection).

With evolution characterized as the consequence of simple, observable natural processes, it can no longer be debated.

My previous popular-science title, "The Top Ten Myths About Evolution" (Prometheus 2006) has been endorsed by the National Center for Science Education, the American Association for the Advancement of Science and numerous well-regarded popular science writers including Ann Druyan, coauthor with Carl Sagan of the 'Cosmos' television series and several books. It is available in libraries and bookstores worldwide, has been translated into Italian, and is also available in a digital format.
"

BACKGROUND:
In spite of its indusrial usefulness and varied daily uses, lead (Pb) pollution is a widespread ecological problem that faces the humans in the 21th century. Pb was found to produces a wide range of toxic effects including neurotoxicity especially to the developing and young offspring. Recently, the utilization of herbal plants has received a significant attention where there has been rising awareness in their therapeutic use; among these is the garlic.
AIM OF THE WORK:
In light of the above, the current study is designed experimentally in female pregnant rats in order to investigate the beneficial role of garlic extract in the protection from the maternal and fetal cerebellar damage that produced by administration of different doses of Pb during pregnancy.
MATERIALS AND METHODS:
Positively pregnant female rats were divided into five groups; one control group, two Pb-treated groups (exposed to 160 and 320 mg/kg b.wt. of Pb, respectively) and two groups treated with both Pb and garlic (exposed to Pb as previous groups together with 250 mg/ kg b.wt. /day of garlic extract). Treatments started from day 1 till day 20 of pregnancy, where the mother rats of different experimental groups were sacrified to obtain the fetuses. Pb level in the maternal nd fetal blood and cerebellum was estimated by spectrophotometry. Specimens of the cerebellum of different mother and fetal groups were processed to histological and immunohistochemical staining for microscopic examination.
RESULTS:
The results showed that administration of Pb to pregnant rats resulted in a dose-dependent toxicity for both mothers and fetuses in the form of decrease of maternal weight gain, placental and fetal weights, brain weight and diminished fetal growth parameters, which were prominent in rat's group treated with larger dose of Pb. In Pb-treated rats, Pb level in blood and cerebellum was high when compared to the control. The histopathological examination of the cerebellum of treated dams and fetuses showed marked alterations mainly in the form of Purkinje cell degeneration and lack of deveopmet of fetal cerebellum. Co-treatment of garlic extract along with Pb resulted in a significant decrease in Pb levels as compared with those treated with Pb alone with improvement of the histopathological changes.
CONCLUSIONS:
This study was useful in evaluating the hazardous effects of uncontrolled use of Pb in general and in assessing the developmental and neurotoxicity of fetuses due to exposure during pregnancy in particular. Co-administration of garlic has beneficial effects in amelioration of Pb-induced neurotoxicity and reversing the histopathological changes of the cerebellum of mother rats and fetuses.
KEYWORDS:
garlic; glial fibrillary acidic protein; lead; purkinje cells

Objectives: Determining nutritional development in wild primates is difficult through observations because confirming dietary intake is challenging. Physiological measures are needed to determine the relative contributions of maternal milk and other foods at different ages, and time of weaning. We used fecal stable carbon and nitrogen isotopes (d 13 C, d 15 N) and fecal nitrogen concentrations (%N) from wild chimpanzees at Ngogo, Uganda, to derive physiological dietary indicators during the transition from total reliance on maternal milk to adult foods after weaning. Materials and Methods: We analyzed 560 fecal samples collected non-invasively from 48 infants, their mothers, and 6 juvenile siblings. Most infant and juvenile samples (90%) were matched to samples collected from mothers on the same day. Isotopic assessments were compared with observations of nursing and feeding.

The traditional terminology of 'scythe' or 'sickle' shaped is observed to be flawed as an effective descriptor for pectoral fin shape in pachycormids. The diversity of pachycormid pectoral fin shapes is assessed across the 14 recognised genera that preserve complete pectoral fins, and improved terms are defined to more effectively describe their form, supported by anatomical observation and aspect ratio analysis of individual fins, and corroborated by landmark analysis. Three clear and distinct pectoral fin structural morphotypes emerge (falceform, gladiform, falcataform), reflecting a diversity of pachycormid lifestyles throughout the Mesozoic, from agile pursuit predator to slow-cruising suspension feeder.

Todo mundo sabe desde criança o que é cocô ou fezes. Esses são
popularmente denominados como merda, bosta, “número 2”, “pupu”, “caquinha”
ou “presentinho da mãe”, entre muitos outros apelidos famosos ou restritos a
certos grupos familiares. Talvez a sua mãe tenha criado um termo só para você...
A relação da criança com o cocô é abordada em um dos capítulo deste livro.
Porém antes disso vamos tratar no presente capítulo e nos demais:
• Qual é a diferença entre Cropologia, Coprofilos e Coprofilia?
• Quais são os tipos de cocô e o que eles nos informam?
• Como eles podem nos ajudar a entender a natureza?

This project analyses a wide range of current literature concerning the origins and evolution
of language. A major focus is on constraining the time in which language evolved, covering
recent and gradual origins hypotheses. Included are models that interpret the foundations
of language as a sudden emergent property, as well as models that propose an accretionary
accrual of a modern suite of linguistic abilities. A ‘gesture-first’ model is presented in line
with the gradual evolution of language, and tool-making is suggested as a reinforcement
framework for language lateralization and even syntactical operations. Finally, the
supportive biological evidence (including the Kebara 2 hyoid bone and FOXP2) is determined
to reinforce the gradual and gestural models rather than emergent models of language
evolution. What we are left with is a model that posits that language cannot have originated
later than 100kya, could have gained prominence between then and 400,000 years ago and
was already subject to a functional cultural-ecological development prior to this.

There are two images of Sir. Patrick Geddes that have been received by subsequent generations, Geddes the Liberal and Geddes the Mystic. This paper examines the ways in which revived sensitivity to the wisdom and limitations of Geddes the Mystic may help facilitate the process of transforming human-nature relations and staving off the cultural and ecological genocide of Modernity.

The Western Hemisphere genus Pseudomorpha Kirby 1825 was last revised by Notman in 1925 based on only a few known species (22) and paltry few specimens (73); other authors have added an additional six species represented by 53 additional specimens since 1925. Baehr (1997) assigned three species from Australia to this genus, albeit in a new subgenus, Austropseudomorpha Baehr 1997. A recent study of collections from throughout the Americas (1757 specimens) has revealed numerous new species that can be arrayed across 19 species groups based on a suite of attributes,

Mangroves are known as the lungs of nature. Kerala once had over 70, 000 hectares of mangroves, fringing its unique estuarine systems. It is considered as the breeding ground of prawns species. There are many factors which facilitate the diversification and abundance of prawn in mangrove area. The detritus content, hiding area, mineral availability, temperature, pH etc. are some of those influential characters. Many prawn species are available in mangrove areas. They are either cultured or naturally occurring. Some of them were studied such as Fenneropenaeus indicus, Metapenaeus dobsoni, Metapenaeus affinis, Macrobranchium rosenbergi, Metapenaeus monoceros. The interview or enquiry method was used for the study.

The outstanding diversity and adaptive radiation of ctenophores in the homogeneous pelagic realm, where niche overlap is high and barriers to genetic exchange are diffuse, remains a mystery of the Plankton Paradox. This study aims to estimate the phylogenetic relationships between extant ctenophores, and develop a preliminary theory on their diversification mechanisms in the ocean.
Features of the natural history and anatomy of different ctenophores were extracted from the literature, and analyzed from videographic, photographic and fresh biological samples from ROV and blue-water SCUBA dives. Phylogenetic trees were built using phenotypic and 18S molecular data. The resulting trees were compared, and ancestral nodes were reconstructed using maximum parsimony.
Results show that many currently used taxonomic units are not monophyletic or inconsistent. Some monophyletic clades share similar feeding strategies, determined by characteristic trophic ecology, functional morphology, and behavior. The ancestor to all extant ctenophores was a deep sea cydippoid. The phylogenetic tree for ctenophores is highly unbalanced by terminal adaptive radiations. Morphological homoplasy correlates with niche similarity. Most of the basal evolution of extant ctenophores occurred in the deep sea.
In conclusion, morphology and molecular based phylogenies are complementary for assessing ctenophore evolution. The actual taxonomic classification for the phylum Ctenophora is inconsistent and should be thoroughly revised. The cladistic units described here could be used to guide a new classification. Phenotypical divergence does not correlate with phylogenetic distance. Adaptive radiation occurs through allopatric speciation in distinct water masses, driven by key adaptations to exploit new trophic resources.

Traditional homegardens in southwest Ethiopia is well-known land use practices playing important role in biodiversity conservation aspects. The objective of this study was to examine the contribution of homegardens towards of biodiversity conservation. Homegarden plant diversity assessment was done. A simple random sampling method was used to select 45 homegardens. Diversity indices were used for analysis. A total of 79 plant species belonging to 41 families were identified. Family Fabaceae and Rutaceae have a relatively higher number of species (6 species each). In terms of habit, (34%) of the species were herbs followed by trees (30%), shrubs (27%) and climbers (9%). Farmers manage both exotic (61%) and indigenous (39%), from which 57% were food and 43% nonfood plant species. The Shannon, Simpson and evenness diversity indexes were 3.27, 0.053 and 0.87 respectively. Coffea arabica was the most frequent (86.67%) species followed by Persea americana (68.89) and Catha edulis (64.44) ...

This research examines the current state of knowledge of Indigenous perspectives on extinction in Canada, with a view to pluralizing contemporary understandings of, and responses to, the Global Extinction Crisis. We worked collaboratively to conduct a systematic review of existing materials, specifically reading and analyzing materials for perspectives from plural Indigenous knowledge systems regarding the relationships between humans and non-humans in the context of extinction, loss, and withdrawal. This knowledge synthesis project reveals a number of key issues to address in decolonizing understandings of extinction in Canada, which will be crucial to address in developing meaningful and robust responses to the contemporary Global Extinction Crisis.

The article gives a comparative description of ecological communities of birds ecosystems that border each other. We studied the birds oak groves and fields around. The types involved in the exchange of individuals between the neighboring communities. The causes and consequences of this interaction.

[AMAZON LINK BELOW TO BOOK ITSELF -- TOC and book summary in downloadable .pdf] 

In the modern jungle of burgers, couches, and remote controls, obesity is an enormous and growing epidemic. Weight-loss books and diet gurus urge us to "listen to our bodies," but our instincts are designed for the African savannah, not food courts. The sugary and fatty foods that we, as hunter-gatherers, are programmed to forage used to be hard to come by. Now they're as close as the vending machine down the hall.

Radical changes are necessary and, fortunately, are biologically easier than small or gradual changes in diet. Barrett tells us how to reprogram our bodies, break food addictions, and ignore our attraction to "supernormal stimuli"—artificial creations that appeal to our instincts more than the natural objects they mimic. Barrett delves into scientific research—from animal ethology to evolution—to show the disastrous direction in which our instincts have led us, and how, using our intellect, we can get back on course.  . . . . . . . .An elegantly written and eye-opening analysis of what makes us fat. -- Steven Pinker, PhD, Johnstone Professor of Psychology, Harvard University, and author of How the Mind Works
. . . . . . .
In this cogent, clearly argued, and thought-provoking book, Barrett shows how we are paying the price for our own plenty. -- David Spiegel, M.D. Medical Director, Center for Integrative Medicine, Stanford University School of Medicine; author of Living Beyond Limits
. . . . . . . .
Offers us a way to understand the pandemic of obesity that we find ourselves in. -- John Ratey, M.D. Clinical Associate Professor of Psychiatry Harvard Medical School, co-author of Driven to Distraction

Interspecific brood parasitism occurs when the eggs of one species are laid in the nest of a different species, but evidence of this phenomenon is scarce. Facultative interspecific brood parasitism was described in Charadriiformes. To our knowledge, this is the first documentation of facultative interspecific brood parasitism in colonially breeding in the species studied here waterbirds.The factors affecting its frequency in relation to colony species composition, nest density, and period of the breeding season was analyzed. Between 2006 and 2012, we monitored 2,493 nests of 5 species: Northern Lapwing (Vanellus vanellus; n = 745), Common Redshank (Tringa totanus; n = 467), Black-tailed Godwit (Limosa limosa; n = 237), Black-headed Gull (Chroicocephalus ridibundus; n = 932 ) and Common Tern (Sterna hirundo; n = 112). Facultative interspecific brood parasitism was observed in 1.3% of all nests. Typically, a single egg was laid in a host nest (59.4%) and the maximum was four parasitic eggs in 3.1% of parasitized nests. The Common Redshank showed the highest frequency of facultative interspecific brood parasitism (59.4%), followed by Northern Lapwing (28.1%). Facultative interspecific brood parasitism occurred most frequently at the beginning of the breeding season – 62.5 % between the end of April and May10th, although the number of active nests peaked later than did the number of parasitized nests. Hatching success of broods containing parasitic eggs was 17.8% and lower than that of non-parasitized nests (23.1%). Interspecific brood parasitism may evolve from conspecific brood parasitism in colonies with high nest densities. Low, but constant frequencies of facultative interspecific brood parasitism may suggest either that this is a strategy to increase fecundity or non-adaptive behavior derived from failures to identify the nest due to the high nest density in the colony.

The traditional terminology of 'scythe' or 'sickle' shaped is observed to be flawed as an effective descriptor for pectoral fin shape in pachycormids. The diversity of pachycormid pectoral fin shapes is assessed across the 14 recognised genera that preserve complete pectoral fins, and improved terms are defined to more effectively describe their form, supported by anatomical observation and aspect ratio analysis of individual fins, and corroborated by landmark analysis. Three clear and distinct pectoral fin structural morphotypes emerge (falceform, gladiform, falcataform), reflecting a diversity of pachycormid lifestyles throughout the Mesozoic, from agile pursuit predator to slow-cruising suspension feeder.

To provide knowledge of scientific methods to farm owner for better management of their integrated farm. To study the habitability of the fish habitat i.e. physico–chemical characteristics of pond viz. Temperature , dissolve oxygen (D.O) , total alkalinity ( T.A) , hydrogen ion concentration (pH) and free carbon dioxide( FCO2).The result revealed that a slight variation occurs in certain physic chemical characteristics due to environmental factors and human activities.

Molecular replicators like viruses, transposons, viroids and so on have the feature that their gene products, or simply their templates, are available to other replicators.  This creates the Theatre for all possible ecological relationships, which we observe.

The extent of changes in basic physiological and
demographic traits associated with reproduction was investigated in the highly cultivated haploid–diploid red alga,
Gracilaria chilensis. Sixty individuals bearing vegetative and
reproductive fronds collected in the natural population of
Niebla (39°52′S, 73°23′W), in Chile, were cultivated under
controlled culture conditions. Our results demonstrated that
vegetative fronds have a higher survival rate and a better
growth rate than reproductive ones irrespective of the type of
individual analyzed (male gametophyte, female gametophyte,
and tetrasporophyte). Moreover, the reproductive fronds clearly
showed a decrease in photosynthetic activity compared to nonreproductive ones. In males and tetrasporophytes, the photosynthetic reduction in reproductive individuals could be
explained by a physical effect of reproductive structure development as well as spores release, disrupting the continuity of
the photosynthetic cortical tissues. Translocation of photoassimilates from nearby vegetative tissue or the previous accumulation of photosynthetic products seems to be a prerequisite for reproductive structure development in this species. Altogether, these results document for the first time in G.
chilensis that reproduction has a strong physiological effect
on male, female, and tetrasporophyte fronds. This trade-off
between reproduction, growth, and survival suggest the existence of reproductive costs in the life history of G. chilensis.

Cet article propose une analyse des différences épistémologiques infrastructurelles entre l’agronomie conventionnelle et les agroécologies, plus particulièrement dans leurs modes d’administration des variations, c’est-à-dire des dynamiques écologiques, évolutives et comportementales du vivant. À travers une synthèse des conditions historiques de l’émergence en France des sciences agronomiques, ce travail tente d’isoler plus précisément les postulats et les protocoles qui ont abouti à l’institutionnalisation d’une forme particulière de science agronomique comme modèle dominant. Nous examinerons également comment cette structuration historique autour d’un paradigme nomologico-prescriptif constitue la condition de possibilité d’une alliance objective entre cette agronomie et l’industrie. En parallèle de ce modèle dominant, cet article fait l’hypothèse que la forme d’enquête écologique historique et située autour de laquelle se structurent les différentes approches agroécologiques, et en particulier la permaculture, semble mieux à même d’informer des pratiques agricoles renouvelées, répondant conjointement à l’érosion politique et scientifique du modèle agronomique dominant et à la crise écologique systémique dont il est en partie responsable.

Autopentaploidy is a death sentence for vertebrate animals, which explains why none has ever been found outside of experimental laboratory settings. Allopentaplody appears to be somewhat better tolerated, with at least a few individuals able to make it past the embryonic stage and some to adulthood. Here, flow cytometry allows for documentation of the first known naturally occurring pentaploid vertebrate—a salamander with four sets of chromosomes from one species, and a single set from a related species.

The European common lizard, Zootoca vivipara, is the most widespread terrestrial reptile in the world. It occupies almost the entire Northern Eurasia and includes four viviparous and two oviparous lineages. We analysed how female snout-vent length (SVL), clutch size (CS), hatchling mass (HM), and relative clutch mass (RCM) is associated with the reproductive mode and climate throughout the species range and across the evolutionary lineages within Z. vivipara. The studied variables were scored for 1,280 females and over 3,000 hatchlings from 44 geographically distinct study samples. Across the species range, SVL of reproductive females tends to decrease in less continental climates, whereas CS corrected for female SVL and RCM tend to decrease in climates with cool summer. Both relationships are likely to indicate direct phenotypic responses to climate. For viviparous lineages, the pattern of co-variation between female SVL, CS and HM among populations is similar to that between individual females within populations. Consistent with the hypothesis that female reproductive output is constrained by her body volume, the oviparous clade with shortest retention of eggs in utero showed highest HM, the oviparous clade with longer egg retention showed lower HM, and clades with the longest egg retention (viviparous forms) had lowest HM. Viviparous populations exhibited distinctly lower HM than the other European lacertids of similar female SVL, many of them also displaying unusually high RCM. This pattern is consistent with Winkler and Wallin's model predicting a negative evolutionary link between the total reproductive investment and allocation to individual offspring.

Tetrapods possess up to five morphologically distinct vertebral series: cervical, thoracic, lumbar, sacral and caudal. The evolution of axial regionalization has been linked to derived Hox expression patterns during development and the demands of weight-bearing and walking on land. These evolutionary and functional explanations are supported by an absence of similar traits in fishes, living and extinct. Here, I show that, Tarrasius problematicus, a marine ray-finned fish from the Mississippian (Early Carboniferous; 359–318 Ma) of Scotland, is the first non-tetrapod known to possess tetrapod-like axial regionalization. Tarrasius exhibits five vertebral regions, including a seven-vertebrae ‘cervical’ series and a reinforced ‘sacrum’ over the pelvic area. Most vertebrae possess processes for intervertebral contact similar to tetrapod zygapophyses. The fully aquatic Tarrasius evolved these morphologies alongside other traits convergent with early tetrapods, including a naked trunk, and a single median continuous fin. Regional modifications in Tarrasius probably facilitated pelagic swimming, rather than a terrestrial lifestyle or walking gait, presenting an alternative scenario for the evolution of such traits in tetrapods. Axial regionalization in Tarrasius could indicate tetrapod-like Hox expression patterns, possibly representing the primitive state for jawed vertebrates. Alternately, it could signal a weaker relationship, or even a complete disconnect, between Hox expression domains and vertebrate axial plans.

There is accumulating evidence that macroevolutionary patterns of mammal evolution during the Cenozoic follow similar trajectories on different continents. This would suggest that such patterns are strongly determined by global abiotic factors, such as climate, or by basic eco-evolutionary processes such as filling of niches by specialization. The similarity of pattern would be expected to extend to the history of individual clades. Here, we investigate the temporal distribution of maximum size observed within individual orders globally and on separate continents. While the maximum size of individual orders of large land mammals show differences and comprise several families, the times at which orders reach their maximum size over time show strong congruence, peaking in the Middle Eocene, the Oligocene and the Plio-Pleistocene. The Eocene peak occurs when global temperature and land mammal diversity are high and is best explained as a result of niche expansion rather than abiotic fo...

The traditional terminology of ‘scythe’ or ‘sickle’ shaped is observed to be flawed as an effective descriptor for pectoral fin shape in pachycormids. The diversity of pachycormid pectoral fin shapes is assessed across the 14 recognised genera that preserve complete pectoral fins, and improved terms are defined to more effectively describe their form, supported by anatomical observation and aspect ratio analysis of individual fins, and corroborated by landmark analysis. Three clear and distinct pectoral fin structural morphotypes emerge (falceform, gladiform, falcataform), reflecting a diversity of pachycormid lifestyles throughout the Mesozoic, from agile pursuit predator to slow-cruising suspension feeder.