Related papers: Molecular diversity as a biosignature
Motivation: ``Molecular signatures'' or ``gene-expression signatures'' are used to predict patients' characteristics using data from coexpressed genes. Signatures can enhance understanding about biological mechanisms and have diagnostic…
The vegetation's ``red edge'', an intensity bump in the Earth's spectrum near 700 $nm$ when sunlight is reflected from greenery, is often suggested as a tool in the search for life in terrestrial-like extrasolar planets. Here, through…
An important goal within the quest for detecting an Earth-like extrasolar planet, will be to identify atmospheric gaseous bio-signatures. Observations of the light transmitted through the Earth's atmosphere, as for an extrasolar planet,…
It is largely taken for granted that differential abundance analysis is, by default, the best first step when analyzing genomic data. We argue that this is not necessarily the case. In this article, we identify key limitations that are…
In a famous paper, Sagan et al.(1993) analyzed a spectrum of the Earth taken by the Galileo probe, searching for signatures of life. They concluded that the large amount of O2 and the simultaneous presence of CH4 traces are strongly…
Life has had a dramatic impact on the composition of Earth's atmosphere over time, which suggests that statistical studies of other inhabited planets' atmospheres could reveal how they co-evolve with life. While many evolutionary pathways…
The astrobiology is an interdisciplinary science, combining the methods and the means of physics, biology, chemistry and astronomy. Its main purpose is to find out if the exoplanets are habitable and if so, to confirm life on them. The…
Monitoring the distribution of microfossils in stratigraphic successions is an essential tool for biostratigraphic, evolutionary and paleoecologic/paleoceanographic studies. To estimate the relative abundance (%) of a given species, it is…
Small bodies, the unaccreted leftovers of planetary formation, are often mistaken for the leftovers of planetary science in the sense that they are everything else after the planets and their satellites (or sometimes just their regular…
Biological systems, unlike physical or chemical systems, are characterized by the very inhomogeneous distribution of their components. The immune system, in particular, is notable for self-organizing its structure. Classically, the dynamics…
Stars, and collections of stars, encode rich signatures of stellar physics and galaxy evolution. With properties influenced by both their environment and intrinsic nature, stars retain information about astrophysical phenomena that are not…
For the first time in human history, we will soon be able to apply the scientific method to the question "Are We Alone?" The rapid advance of exoplanet discovery, planetary systems science, and telescope technology will soon allow…
We use the critical step model to study the major transitions in evolution on Earth. We find that a total of five steps represents the most plausible estimate, in agreement with previous studies, and use the fossil record to identify the…
In the laboratory, the photo-and thermochemical evolution of ices, made of simple molecules of astrophysical relevance, always leads to the formation of semi-refractory water-soluble organic residues. Targeted searches for specific…
As oxygen is essential for respiration and metabolism for multicellular organisms on Earth, its presence may be crucial for the development of a complex biosphere on other planets. And because life itself, through photosynthesis,…
Can multicellular life be distinguished from single cellular life on an exoplanet? We hypothesize that abundant upright photosynthetic multicellular life (trees) will cast shadows at high sun angles that will distinguish them from single…
This paper deals with the derivation of a collective model of cell populations out of an individual-based description of the underlying physical particle system. By looking at the spatial distribution of cells in terms of time-evolving…
Understanding functional diversity, the range and variability of species' roles and actions within their communities, is key to predicting and preserving the functions that sustain both nature and human well-being. In this paper, we provide…
Biodiversity is essential to the viability of ecological systems. Species diversity in ecosystems is promoted by cyclic, non-hierarchical interactions among competing populations. Such non-transitive relations lead to an evolution with…
On the Earth, photosynthetic organisms are responsible for the production of virtually all of the oxygen in the atmosphere. On the land, vegetation reflects in the visible, leading to a red edge that developed about 450 Myr ago and has been…