3 Oct 2022

The greatest animal radiation on Earth was promoted by a stable marine redox landscape

The greatest rise in marine biodiversity in all of Earth’s history surprisingly was not fuelled by ocean oxygenation. Instead, oceanic redox stability appears to have favoured increased ecosystem resilience and – ultimately – a massive rise in global biodiversity levels. Oxygen rise occurred later… PhD student Alvaro del Rey measured the uranium isotope composition of […]

4 Jul 2022

Talk 6/7-2022: Dahl colloquium at IPM, Hamburg University

July 6th, 2022 @ 17:15. Institut für Pflanzen und Mikrobiologie (IPM) is at Ohnhorststr. 18 in Klein Flottbek, a suburb of Hamburg. Tais will give a lecture for the Institute for Plants and Microbiology (IPM) at Hamburg University entitled: “Atmospheric oxygenation and climatic cooling during the early colonization of the terrestrial environment by plants”. The presentation will […]

5 May 2022

Telling actual time in the rock record

We have discovered a new method to tell time in the Geological record, using core scanning XRF analyses, which we have now applied to Cambrian and Ordovician rocks to refine the Geological Time Scale. The study, led by my PhD student Zhengfu Zhao, is now published in Nature Communications. The new method was first discovered […]

18 Oct 2021

Podcast: The Geobiological History of Earth

Danish Science journalist Lone Frank interviews Tais W. Dahl about his research. Her podcast series is called “24 Questions to the Professor” and runs in Danish. The podcast went from the formation of the Earth, through microbial evolution and into the world of animals and the colonization of land. What drove environmental evolution and Earth’s […]

14 Oct 2021

Tais is pitching a Science Slam in the Planetarium

On November 19, the Danish rapper Per Vers will orchestrate Science Slam in the Tycho Brahe Planetarium. The program is found here https://planetarium.dk/program/science-slam-faa-toptunet-din-viden-om-universet/. Tais will give a 7 minutes pitch from his research

23 Apr 2021

EarthTalks at GEOCENTER Denmark

The Section for Geobiology at GLOBE has helped organizing the spring season of EarthTalks 2021, and we welcome interested students and researchers to participate over Zoom (link below). The talks will not be recorded. Earth Talks Lecture Series – Spring 2021 Friday afternoons 14:00-15:00 DK time (sharp) 23/4 – Prof. Sigur∂ur Gislason, University of Iceland The […]

28 Mar 2021

Did land plants alter erosion rates on Earth?

A discussion arises from the recent review article in Chemical Geology, where Tais W. Dahl and Susanne Arens concluded that land plants did not forever increase the physical weathering rates of the continental crust. This conclusion was reached from the records of preserved sediment rock volume and the timing of plant-assisted weathering as recorded in […]

27 Jan 2021

The Carlsberg foundation supports field work in Siberia

The Carlsberg Foundation is sponsoring field work led by Tais W. Dahl to Arctic Siberia, where an important climate catastrophe is recorded in marine sedimentary rocks. The expedition will bring back data and samples deposited in the oceans during a climate event that caused sulfidic anoxia to suddenly expand in warming oceans and wipe out […]

12 Oct 2020

Press release: Early animals had a shorter day

In a brief story published in Danish on Videnskab.dk, Aske L. Sørensen and Tais W. Dahl explain one of the consequences of their latest EPSL paper: Earth was spinning faster 500 million years ago. The scientific paper entitled “Astronomically forced climate change in the Late Cambrian” documents Milankovitch-cycles in two drill cores through the Alum […]

4 Aug 2020

Tracing global ocean oxygenation from calcitic brachiopods

The uranium isotope composition of seawater provide insights to how much sediment burial occurs globally in anoxia settings. Therefore, it is desirable to measure uranium isotopes to track the oxygenation state of the oceans through geological time. However, there is currently no geological archive that can reliably record the composition of ancient seawater. Calcitic brachiopods […]