Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Experimental and numerical modeling of liposome congregation in meteorite craters of Early Earth

Vladimir M. Subbotin, Benjamin A. Turner, Brian A. Davies, Alric G. Lopez, Gennady Fiksel

Abstract

This paper provides experimental and numerical evidence supporting the occurrence of liposome congregation at the floors of meteor craters on Early Earth. This work builds on our earlier research, which demonstrated that liposomes submerged in a shallow Archean pond are protected from harmful UV radiation. This protection allows them to survive long enough for autocatalytic replication of amphiphiles and for mutation and selection of assemblies that maximize membrane stability. For liposomes to fuse, grow, exchange contents and membranes, and divide, they need to establish a population, which means forming a dense conglomerate that enables close physical contact. The study demonstrates that such a congregation is feasible in bowl-shaped meteor craters on Early Earth, especially under periodic seismic disturbances.

Experimental and numerical modeling of liposome congregation in meteorite craters of Early Earth

Abstract

This paper provides experimental and numerical evidence supporting the occurrence of liposome congregation at the floors of meteor craters on Early Earth. This work builds on our earlier research, which demonstrated that liposomes submerged in a shallow Archean pond are protected from harmful UV radiation. This protection allows them to survive long enough for autocatalytic replication of amphiphiles and for mutation and selection of assemblies that maximize membrane stability. For liposomes to fuse, grow, exchange contents and membranes, and divide, they need to establish a population, which means forming a dense conglomerate that enables close physical contact. The study demonstrates that such a congregation is feasible in bowl-shaped meteor craters on Early Earth, especially under periodic seismic disturbances.
Paper Structure (8 sections, 3 equations, 7 figures)

This paper contains 8 sections, 3 equations, 7 figures.

Table of Contents

  1. Introduction
  2. Experiment
  3. Earthquake literature data
  4. Experimental setup
  5. Experimental results
  6. Numerical simulations
  7. Liposome protection against UV destruction in crater geometry
  8. Summary and conclusions

Figures (7)

  • Figure 1: A drawing of a crater model showing an overview and detail views.
  • Figure 2: Experimental setup. A stainless steel tray is connected to a stand with four springs. The crater model is mounted on a $\unit [2]{cm}$-thick wooden plate, which is placed on top of a $\unit [3]{cm}$-thick polyurethane foam layer resting within the tray. Two weights are dropped from $h = \unit [25] {cm}$.
  • Figure 3: Summary of particle dynamics. The top and bottom rows compare results for steel and aluminum rods, respectively, while the left and right columns show the initial and final stages. (b) Dropping steel rods leads to nearly complete particle collection at the center after N = 40 drops. (d) Dropping aluminum rods results in a profile that, although somewhat peaked, remains noticeably wide even after 80 drops.
  • Figure 4: A thousand particles, each with a diameter of $d = \unit [350]{\mu m}$ and density of $\rho = \unit [1.2]{g/cm^3}$ are submerged in water (colored in cyan) and are initially uniformly distributed across the curved bottom, as shown in the red circles. It is assumed that after the weights impact the crater, the crater descends and then rebounds, striking the particles and initiating their motion. Because of the concave shape of the bottom, the momentum transferred to the particles has both vertical and horizontal components, depending on their initial positions, as indicated by the arrows.
  • Figure 5: Particle distribution over the bottom of the cavity after 60 impacts at a rebound velocity of $\unit [0.5] {m/s}$.
  • ...and 2 more figures