Disclaimer: due to the coronavirus pandemic, this course description might be subject to changes.
Disciplines: Biology, Paleontology, Geology, Geophysics, Geochemistry, Astronomy.
Topics: 1st Geology: setting the stage for life
Timescale, continents, sedimentary systems
2nd Young Earth, young life
Isotopes, origin of life, Exo life
3rd Crises and opportunities
Ediacara to Burgess Shale ; Mass extinctions in the Ordovician and Devonian
4th Tree of life
General outline of living organisms, stromatolites, Bauplans in life
5th Evolution towards land
Adaptations for life on land in plants, arthropods and chordates
Admission requirements:
This course is an (extracurricular) Honours Class: an elective course within the Honours College programme. Third year students who don’t participate in the Honours College, have the opportunity to apply for a Bachelor Honours Class. Students will be selected based on i.a. their motivation and average grade.
Description:
Life in all its diversity evolved in the marine environment. In this course taught at Leiden University and at the Marine Center of the University Marie et Pierre Curie, France, in Roscoff, we teach aspects of the Tree of Life, we focus on the transition from mono-cellular life to animal life conquering the continents in the early Paleozoic, and we address Earth history from the time of the origin of life to the adaptations that made the emergence of land life possible.
We bring together a multi-disciplinary team of marine biologists, ecologists, physicists and geophysicists, isotope geochemists, paleontologists and geologists to teach a course in geo-biology with special interest in the Tree of Life, the origin of life, and the environments in which life evolved.
There is some consensus that the origin of life dates back to the earliest Archean or late Hadean. The earliest sediments in the rock record contain banded iron formation lithologies, taken as indicative for oxygen production, and hence photosynthesis. At least as enigmatic is the emergence of multi-cellular life in the late Proterozoic. Was the increased oxygen partial pressure in the atmosphere necessary or environmental stress caused by the (perhaps first) ice ages in the late Proterozoic? And how was the development of skeletal elements related to the Cambrian explosion, in which we recognize all of the modern phyla.
Understanding early life starts with the study of recent communities. Though some phyla from the beginning of the Phanerozoic have disappeared, all recent phyla have their earliest representatives in the Paleozoic or even the Proterozoic. Basic knowledge of the Tree of Life is necessary to understand the early evolution. In combination with the geological record, we can link this to the adaptations required at various stages in the evolution of life.
Course objectives:
After completion of the course the students will be able to:
Identify key fossils from the Paleozoic era.
Identify marine organisms as can be found along the coast of Normandy near Roscoff.
Recognize geological structures in the field.
Read a geological map.
Identify a range of sedimentary and magmatic rocks.
After completion of the course the students will know:
The evolution of continents since the early Archean era.
The radiation of life in the Eocambrian and early Phanerozoic.
Adaptation of life to living on land in the Paleozoic era.
The major Bauplans of marine organisms.
The basic structure of the Tree of Life.
Students will have an understanding of the relation of land forms and underlying geological structures.
Students will have an understanding of different taxa of the Tree of life, both in the paleontological record and in the modern marine environment.
Students will develop a holistic view of earth processes occurring at the earth surface through time from geophysical and geochemical view points on the origin and evolution of life.
Programme and timetable:
Lecture series week 23 and week 24.
Theme 1: Geology: setting the stage for life
Lecture 1: From planetary accretion to continents. Earth history in the early stages of the earth.
Lecture 2: Timescales in Geology. From isotopic dating techniques to division of Earth history into different periods.
Lecture 3: The origin and significance of the earth’s magnetic shield.
Lecture 4: The composition of the early atmosphere, the oceans, and the sea floor, how this composition changed with time, and its relevance for the origin of life on earth.
Theme 2: Young Earth, young life
Lecture 5: Stable isotope systems as tracers of life:
Si and Fe isotopes as indicators of metabolism in the Archean.
13C/12C fractionation through time, biological and inorganic causes.
Lecture 6: Exo Life.
Lecture 7: Origin of Life: The history of theories on the origin of life or biogenesis. Comparison of chemical and physical approaches to biogenetic theories. Biogenesis will be placed within the ecological framework of a development of reducing oxidising conditions.
Lecture 8: The thermodynamics of photosynthesis and its role in the development of the biosphere and its import on the atmosphere.
Theme 3: Crises and opportunities
Lecture 9: Proterozoic – Cambrian transition. The first fossils of multicellular organisms, known as the Ediacara fauna, represent life forms very different of anything living today. After the Cambrian explosion, fossils show more familiar Bauplans. However, deposits like the Burgess shale revealed that in that period too, organisms thrived in the oceans unlike anything living today.
Lecture 10: Crises and opportunities. During the Palaeozoic, two mass extinctions occurred. The third major extinction wave, the largest ever recorded, signified the end of the era. About the possible causes of the various mass extinctions, the devastation they caused, and the opportunities provided during the aftermath.
Theme 4: Tree of life
Lecture 11: Genealogy of living organisms. From single cell to higher organisms.
Lecture 12: Stromatolites, a singular visual portal into deep time on earth, the emergence of life, and the evolving of the beautiful forms of life of modern time
Lecture 13: Modelling gene-regulation and cell-movement in early development of the sea anemone Nematostella vectensis and the scleractinian coral Acropora mellipora.
Theme 5: Evolution towards land
Lecture 14: A Tree of Plants: From a blue to a green planet
Lecture 15: on the emergence of insects from crustaceans
Lecture 16: Evolution of Chordata: there is something fishy about us.
Lecture 17: To boldly go where no vertebrate has gone before. During the Devonian the vertebrates started exploring and exploiting the land. A massive change, leading to a number of adaptation to deal with the hostile environment outside the water.
Excursion: Saturday, July 3 - Saturday, July 17
Day 1: Travel + Sediments Paris Basin near Etretat, Normandy France
Day 2: May-sur-Laize: geology of Paleozoic and Late Proterozoic sediments; travel to Roscoff.
Day 3: Tree of Life (+ plankton?) sampling I.
Day 4: Crozon Paloeozoic sediments excursion;
Day 5: Trebeurden, Ile de Milliau; Early Proterozoic gneisses, Granite intrusion
Day 6: Crozon profile: geology assignment.
Day 7: Sampling by boat in the estuary, sampling sea floor; Report profile Crozon due
Day 8: Fish market; fish anatomy practical; BBQ
Day 9: reporting; excursion to Le Conquet, metamorphic rocks.
Day 10: Tree of Life sampling II
Day 11: Lab day, reporting planktn project.
Day 12: Les Sept Iles excursie (Perros-Guirec); afternoon: mud flats of Molaix
Day 13: Bio reports due; student symposium.
Day 14: Travel back to Leiden
The course schedule will be made available prior to starting of the course.
Location:
Huygens Lab for teaching the course on Mondays / Thursdays in week 24.
Please note: due to the corona pandemic it is still unclear if it will be possible to travel abroad as part of this Honours Class.
Reading list:
Marine biology, Jeffrey S. Levinton, Oxford University Press, 3rd edition, 2008, ISBN13: 978-0-19-532694-9
An Introduction to the Earth-Life System, edited by Charles Cockell (schrijvers, Charles Cockell, Richard Corfield, Neil Edwards, en Nigel Harris). ISBN: 9870521729536 (paperback versie), jaar van uitgave 2007.
The world’s beaches. A global guide to the science of the shoreline, O.H. Pilkey, W.J. Neal, J.T. Kelley and J.A.G. Cooper. University of California Press, 2011. ISBN 978-0-520-26872-2.
Excursion guides.
Library books, covering the various aspects of the excursion, will be made available during the field course.
Course load and teaching method:
This course is worth 5 ECTS, which means the total course load equals 140 hours.
Seminars: 24 hours (mandatory)
Excursions: 1 excursion à 116 hours (mandatory) See assessment.
Assessment methods:
1
Learning aim: Interactive engagement with course material
Assessment: Active in-class participation
Percentage: 5%
Deadline: None
2
Learning aim: Understanding of course content
Assessment: Blog-reports of each lecture via Brightspace (100 – 200 words)
Percentage: 10%
Deadline: Weeks 23 - 24
3
Learning aim: Individual engagement with course material
Assessment: Oral reports in the form of a class room presentation. Topics per excursion day (groups of 2, 15 min. max. each)
Percentage: 5%
Deadline: Week 34 - 35
4
Learning aim: Expression of holistic understanding of the course
Assessment: Final reports on excursion assignments:
1. Marine Biology. (30%)
2. DNA Laboratory experiment (20%)
3. Geology (30%)
Percentage: 80%
Deadline: Week 35,
Submission: final day of the excursion
Students can only pass this course after successful completion of all partial exams.
The assessment methods will be further explained in the first session of the class.
Brightspace and uSis:
Brightspace will not be used in this course. Students will be invited to join a shared folder prior to the start of the coursee.
Please note: students are not required to register through uSis for the Bachelor Honours Classes. Your registration will be done centrally.
Registration process:
UPDATE 29-10:
Registration will be possible from Monday 9 November 2020 up to and including Thursday 19 November 2020 through the Honours Academy website.
Contact:
Professor dr. J.R. Wijbrans j.r.wijbrans@science.leidenuniv.nl