Skip to main content

Unit information: Geobiology in 2023/24

Please note: It is possible that the information shown for future academic years may change due to developments in the relevant academic field. Optional unit availability varies depending on both staffing, student choice and timetabling constraints.

Unit name Geobiology
Unit code EASC20024
Credit points 10
Level of study I/5
Teaching block(s) Teaching Block 1A (weeks 1 - 6)
Unit director Professor. Donoghue
Open unit status Not open

Mandatory Year 1 units of an Environmental Geoscience, Geology or Palaeontology and Evolution degree programme at Bristol.



School/department School of Earth Sciences
Faculty Faculty of Science


Geobiology is the study of the interactions that occur between the biosphere (living organisms and their products) and the geosphere (the Earth and its atmosphere). Geobiology encompasses the fields of astrobiology, biogeochemistry, geomicrobiology, isotope geochemistry and palaeobiology.

The unit has the immodest aim of unraveling the majority of evolutionary history – from life’s origin, through LUCA (the Last Universal Common Ancestor), the emergence of unicellular ‘bacterial’ lineages that still dominate life on Earth, to the origin of eukaryotes and conclude with the origin of animals. This is the portion of evolutionary history that is not conventionally taught, because the evidence cannot be read simply from the fossil record, but encompasses disciplines as diverse as biogeochemistry, molecular biology and isotope geochemistry. Organised around the architecture of the Tree of Life, this unit will explore not only the multifarious lines of evidence for the evolutionary emergence of various groups, but also their consequence for shaping the biosphere, the evolution of biogeochemical cycles and global environmental change.

Intended learning outcomes

On successful completion of the unit you will be able to:

  • Describe how the branches in the tree of life are arranged, the evidence supporting their arrangement, and be able to exploit tree topologies for their predictions concerning the sequential order of lineage divergence
  • Critically evaluate competing hypotheses on the origin of life
  • Describe and explain the inter-relationships between life and geochemical processes at scales ranging from individual organic molecules
  • Assess the implications of isotopic and biogeochemical data for detecting life and its interactions with the abiotic environment
  • Describe and give examples of the effect that life has had on the Earth's geochemical cycles
  • Describe and give examples of the effect that life has had on the formation of various geological deposits of economic importance.
  • Critically evaluate the various methods employed in calibrating the tree of life to time.
  • Describe how molecular developmental genetics informs the processes underpinning the divergence of animal bodyplans

Teaching details

The unit will be taught through a combination of

  • asynchronous online materials and, if subsequently possible, synchronous face-to-face lectures
  • synchronous office hours
  • asynchronous directed individual formative activities and exercises
  • guided, structured reading
  • practical work in the laboratory

Students who either begin or continue their studies in an online mode may be required to complete practical work, or alternative activities in person, either during the academic year 2020/21 or subsequently, in order to meet the intended learning outcomes for the unit, prepare them for subsequent units or to satisfy accreditation requirements.

Assessment Details

Coursework 100% - comprising two reports in 'Biology Letters' journal format interpreting the results of laboratory exercises (2500 words each).

Report 1 is formative and Report 2 is worth 100%. Formative feedback will be provided on Report 1 in preparation for writing Report 2.


If this unit has a Resource List, you will normally find a link to it in the Blackboard area for the unit. Sometimes there will be a separate link for each weekly topic.

If you are unable to access a list through Blackboard, you can also find it via the Resource Lists homepage. Search for the list by the unit name or code (e.g. EASC20024).