Our knowledge of the early Earth offers a key constraint on hypotheses for the origins of life. Unfortunately, the overwhelming majority of the oldest rocks on Earth have been destroyed or altered by geological processes such as tectonic shift. Consequently, the geological record is extremely poor for the first billion years of Earth's 4.5-billion-year history.¹⁷ The earliest confirmed fossil organisms to have yet been discovered are 3.5 billion years old,¹⁸ and so all we know is that life arose during a 1-billion-year window — an enormous span of time, roughly twice as long as complex animals have existed.

Future Horizons:

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5-yearhorizon

Criteria for assessment of evidence for life is developed

Explicit criteria are developed for the assessment of purported evidence for early life on Earth.

10-yearhorizon

Earth's formation is better understood

We have an improved understanding of Earth's formation via study of exoplanets.

25-yearhorizon

Origin of Earth's water clarified

Greater clarity is achieved on the origin of Earth's water and the initial development of oceans and land.

Improvements in our understanding of the geological record will continue to narrow down when and how life may have formed. This may happen through discovery of hard evidence of life at an earlier date, through innovative synthetic biology and evolutionary systems biology tools that reconstruct ancient life,¹⁹ or through demonstrations that conditions before a certain point were unremittingly hostile to life.²⁰

There is currently limited geological evidence to illuminate conditions on the early Earth. New discoveries about the temperature range, the presence or absence of exposed land, and the chemical make-up of the oceans and atmosphere, as well as about the elemental composition, would all provide useful and significant information from which research could gain a better understanding of which scenarios of the origins of life are plausible.²¹ ²² ²³ These questions are bound up with fundamental problems in geology, notably the origin of modern plate tectonics.²⁴

The geological record - Anticipation Scores

The Anticipation Potential of a research field is determined by the capacity for impactful action in the present, considering possible future transformative breakthroughs in a field over a 25-year outlook. A field with a high Anticipation Potential, therefore, combines the potential range of future transformative possibilities engendered by a research area with a wide field of opportunities for action in the present. We asked researchers in the field to anticipate:

The uncertainty related to future science breakthroughs in the field
The transformative effect anticipated breakthroughs may have on research and society
The scope for action in the present in relation to anticipated breakthroughs.

This chart represents a summary of their responses to each of these elements, which when combined, provide the Anticipation Potential for the topic. See methodology for more information.