Thousands of teeth tell the long history of sharks

I en ny studie har forskare från Uppsala universitet tillsammans med internationella kollegor undersökt vilka avtryck en torftig livsmiljö för suggor lämnar på nästa generation. Grisarna i studien föddes upp i Brasilien och hölls enligt uppfödningsstandard i landet. Suggornas obekväma och ostimulerande miljö förde med sig flera olika typer av förändringar i epigenomet hos avkomman.

Mikael Thollesson har medverkat i UppTalk Weekly och pratat om utforskning av okända svampdjur i havet. Se samtalet nedan.

Forskaren Grzegorz Niedzwiedzki har medverkat i en dokumentär som heter "Dinosauriejägaren" från Sveriges Radio P4.

Mikael Thollesson kommer att vara med i samtalsserien UppTalk weekly den 18 april mellan 12:00 och 12:30. Samtalet sänds live på Youtube. 

Madagascar has an enormous biodiversity, with most of the plant and animal species found nowhere else on earth. But the rich life on the island is in grave danger and governments and environmental organisations must help. This is claimed by a large number of researchers, including from Uppsala University, in the journal Science.

To improve understanding of mental health, today’s symptom-based diagnoses need to be complemented with biological criteria accounting for differences between individuals and the sexes. A major EU-funded research project, coordinated by Uppsala University, will pursue an interdisciplinary path towards better strategies to protect vulnerable individuals from mental illness.

Researchers at Uppsala University have discovered and characterised a DNA sequence found in jawed vertebrates, such as sharks and humans, but absent in jawless vertebrates, such as lampreys. This DNA is important for the shaping of the joint surfaces during embryo development.

Den mesta av en svamps genetiska variation uppkommer i de ganska kortlivade svampsporerna. I mycelet, som svampen tillbringar den absolut största delen av sin livscykel som, skapas inte alls lika mycket variation. Det visar forskare från Uppsala universitet i en ny studie som publiceras i den vetenskapliga tidskriften PNAS.

Roughly 200-million-year-old footprints of large predatory dinosaurs, along with the skeletons of other dinosaurs, animals and plant fossils, have been discovered in the Norra Albert clay pit in northern Skåne. The discoveries surprised the researchers, as they show that carnivorous dinosaurs of this size existed much earlier than previously known.

Following an exceptionally successful scientific expedition to Greenland, more than 200 kg of fossil material is on its way back to Uppsala. “The discoveries will revolutionize our understanding of the early evolution of land vertebrates” says Per Ahlberg, Professor of evolutionary Organismal Biology and leader of the expedition.

Most researchers can only guess how animals that lived hundreds of millions of years ago were built internally, given that innards disintegrate. However, researchers have now found extremely well-preserved hearts, stomachs, livers and intestines in 380-million-year-old placoderm fossils.

Tillgång till sötvatten är helt nödvändigt för vår överlevnad. Utan det lider vi brist på dricksvatten, fisk att äta och möjlighet att bevattna åkrar. Sjöar, floder och pölar är dessutom hem för otaliga arter. Men hur de här känsliga ekosystemen är uppbyggda är inte helt känt.

An international team led by Uppsala University researchers has uncovered that eukaryotes (organisms with a cellular nucleus) have made hundreds of big leaps from sea to soil and freshwater habitats, and vice versa, during their evolution. The results, published in Nature Ecology and Evolution, also provide insights into what the habitats of our ancient microbial ancestors looked like.

Idag kan avancerad dna-teknik hjälpa oss förstå hur människor och folkgrupper levde och interagerade för tusentals år sedan. Följ med in i Uppsala universitets Ancient DNA-laboratorium, som sätter ljus på forntida kvarlevor.

Coral species exhibit different temperature tolerances. This is in part due to the composition of their microalgae symbionts. With a new method, researchers from Uppsala University were able to predict how individual microalgae might behave under future temperature stress and identify more tolerant coral symbionts.

För knappt 400 miljoner år sedan kravlade en grupp fiskar upp på land och gav upphov till de fyrbenta ryggradsdjuren. Per Ahlberg, professor i evolutionär organismbiologi, har länge forskat om de här varelserna som kallas tetrapoder och är alla groddjurs, reptilers, fåglars och däggdjurs gemensamma förfäder.

Europeiska forskningsrådet (ERC) delar ut 313 nya ERC Consolidator Grants i 24 olika länder. Bland mottagarna finns två forskare vid Uppsala universitet: Maria Tenje och Fabien Burki. Dessutom delas ett ERC Starting Grant ut till Ingela Lanekoff.

An African man who lived just 350 years ago was buried in a prehistoric shell midden in Amoreira in Portugal. This was very surprising because Amoreira and other midden sites in the Muge region are well known by archaeologists for the cemeteries of the last hunter-gatherers living in the area 8 000 years-ago.

The asteroid which killed nearly all of the dinosaurs struck Earth during springtime. This conclusion was drawn by an international team of researchers after having examined thin sections, high-resolution synchrotron X-ray scans, and carbon isotope records of the bones of fishes that died less than 60 minutes after the asteroid impacted. The team presents its findings in the journal Nature.

By linking human population studies with experiments in cell and animal models, researchers have provided evidence that complex mixtures of endocrine disrupting chemicals impact children’s brain development and language acquisition. With their novel approach, the scientists show that up to 54 per cent of pregnant women were exposed to experimentally defined levels of concern.

In summer 2021, in an opencast clay mine in Borkowice, Poland, researchers found what may be Europe’s largest array of dinosaur tracks. Several hundred very well-preserved footprints from at least seven dinosaur species were discovered, and the scientists say far more remain to be found.

Thanks to an SEK 10 million donation from two private citizens, a new foundation will be established: The Lennart and Kerstin Holm Scholarship Fund for Mycological Research. This will have a significant impact on fungal research at Uppsala University, which examines systematics, ecology and evolutionary biology.

De äldsta kända fotspåren av förmänniskor har hittats på Medelhavsön Kreta och är minst sex miljoner år gamla, enligt ett internationellt team av forskare från Tyskland, Sverige, Grekland, Egypten och England. Studien har publicerats i tidskriften Scientific Reports och leds av leds av Uwe Kirscher och Madelaine Böhme vid universitetet i Tübingen.

Tillgången på byten och förmågan att anpassa sig till förändrade miljöer har haft avgörande betydelse i hajarnas utveckling. En studie där över 3 000 hajtänder analyserats ger ny inblick i hur dagens hajgrupper uppkom. Resultaten har publicerats i den vetenskapliga tidskriften Current Biology.

The Philippine ethnic group Ayta Magbukon has the highest proportion of genes from our extinct relatives, the Denisovans, a new study led by Uppsala University shows. Their Denisovan share far exceeds that of ethnic groups in Papua New Guinea, who previously held the record. The study is published in the scientific journal Current Biology.

Den kortbenta fladdermusfästingen är en ganska vanlig blodsugare på fladdermöss i Sverige och det händer ibland att den också biter människor. I en ny studie beskriver forskare från Uppsala universitet och Linköpings universitet hur de funnit en art av borrelia hos fladdermusfästingar som de misstänker framkallar sjukdom hos människa. Det här är första gången arten påträffats i Sverige.

The tiny beetle Triamyxa coprolithica is the first-ever insect to be described from fossil faeces. The animal the researchers have to thank for the excellent preservation was probably the dinosaur ancestor Silesaurus opolensis, which 230 million years ago ingested the small beetle in large numbers.

För första gången har man lyckats få fram hela genomet från de 35 000 år gamla skallbenen från kvinnan Peştera Muierii 1, i Rumänien. Nu har en forskargrupp, ledd av Mattias Jakobsson vid institutionen för organismbiologi, klarlagt hennes kompletta dna.

Plastkemikalien bisfenol F kan framkalla förändringar i en gen som är viktig för neurologisk utveckling. Det har forskare vid Uppsala universitet och Karlstads universitet upptäckt. Mekanismen kan förklara varför exponering för ämnet under fosterstadiet kan kopplas till lägre IQ vid sju års ålder, ett samband samma forskargrupp tidigare sett.

The European Research Council (ERC) has now distributed the grants in its 2020 ERC Advanced Grants call and Uppsala University is one of the recipients. The grant of EUR 2.4 million goes to Per Ahlberg, Professor of Evolutionary Organismal Biology, whose research seeks to reveal more about the origins of land animals by studying the tracks left by our more than 360 million-year-old ancestors – the ‘tetrapods’.

Over 50 millennia, at least five major immigration waves have successively populated the Philippines, the most comprehensive survey of genetic variations in the country to date shows. This Uppsala University study comprises 2.3 million DNA markers from some 1,000 individuals and suggests that climate change may have played a role in the mass movement of populations.

When and how bone marrow first originated in the limbs of early four-legged animals is disputed in evolutionary biology. With the help of powerful X-ray technology, an international research team, led by Uppsala University, has now discovered that this evolutionary adaptation most likely took place after the first tetrapods stepped ashore. The study is published in the scientific journal eLife.

The effects of the endocrine disruptor linuron on frogs are not limited to those exposed, but are passed on to their offspring and grand-offspring. First generation offspring have reduced body weight and decreased fertility, while second generation offspring have increased body weight and a disrupted metabolism. This is demonstrated by a new study conducted by researchers at Uppsala University and Stockholm University that has now been published in the journal Science of the Total Environment.

How can stress in animals be measured? Scientists from Uppsala University and elsewhere have now found that what are known as epigenetic biomarkers could be used to detect long-term exposure to stress in commercially raised chickens. This may, in time, lead to improved conditions in animal rearing. The study has been published in the journal Frontiers in Genetics.

Big tidal ranges some 400 million years ago may have initiated the evolution of bony fish and land vertebrates. This theory is now supported by researchers in the UK and at Uppsala University who, for the first time, have used established mathematical models to simulate tides on Earth during this period. The study has been published in Proceedings of the Royal Society A.

A team of scientists led from Uppsala University have described the earliest known example of dentary bone with two rows of cusps on molars and double-rooted teeth. The new findings offer insight into mammal tooth evolution, particularly the development of double-rooted teeth. The results are published in the scientific journal PNAS.

The great long-necked dinosaurs, or sauropods, of the Jurassic and Cretaceous periods were the largest animals ever to live on land. In a paper published in Current Biology, an international team of researchers including members from Uppsala University use cutting-edge imaging technology to give us a unique glimpse of the very beginning of a sauropod life: the face of an unhatched young inside an egg.

Ett internationellt forskarteam har kartlagt genomet hos tuataran, en sällsynt reptil som endast finns på Nya Zeeland. Arten, som också kallas bryggödla på svenska, bildade en egen evolutionär gren redan för 250 miljoner år sedan. I den nya studien har forskarna bland annat kunnat se att tuataran har fler gener som skyddar mot åldersrelaterade skador än något annat undersökt ryggradsdjur. Forskningen publiceras i tidskriften Nature.

Vilken sorts utbyte hade stenålderns olika kulturer med varandra? I en ny tvärvetenskaplig studie har forskare kombinerat arkeologisk och genetisk information för att bättre förstå kulturella influenser från stridsyxekultur som påträffats i gravar från den så kallade gropkeramiska kulturen. Resultaten publiceras i den vetenskapliga tidskriften American Journal of Physical Anthropology.

Forskare vid Uppsala universitet har, tillsammans med kollegor i Israel, lyckats utvinna DNA ur de över 2 000 år gamla Dödahavsrullarna. Informationen om djuren vars skinn använts till pergament gör det möjligt för historiker att dra slutsatser om vilka textfragment som hör ihop men också om hur pass representativa texterna verkligen är för judendomen vid den här tiden.

Sharks have roamed the earth’s oceans for around 450 million years. Although they survived the catastrophic extinction event that wiped out the dinosaurs, that event did alter the balance between two important shark groups. In his degree project, Mohamad Bazzi investigates which types of shark have been most successful during different periods.

On March 5 - 7, Uppsala University and SLU hosts the science festival Scifest at Fyrishov. Many scientists from the Department of Organismal Biology will be there.