Naked Science Forum

Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: jeffreyH on 15/07/2017 12:23:30

Title: Will something like Tardigrades be found on other worlds?
Post by: jeffreyH on 15/07/2017 12:23:30
This may be very likely if they can evolve within such environments.
https://en.m.wikipedia.org/wiki/Tardigrade
What do you think?
Title: Re: Will something like Tardigrades be found on other worlds?
Post by: chiralSPO on 15/07/2017 21:59:53
...or if they can survive the journey between worlds!

http://www.popularmechanics.com/space/a11137/secrets-of-the-water-bear-the-only-animal-that-can-survive-in-space-17069978/
Title: Re: Will something like Tardigrades be found on other worlds?
Post by: Kryptid on 15/07/2017 22:45:00
Tardigrades can survive extreme conditions, but they cannot thrive or reproduce in them. They enter stasis when confronted with extraordinary environments. They still need liquid water, breathable oxygen and food in order for a breeding population to be maintained. This could allow them (or something like them) to survive on worlds with eccentric orbits which causes the weather to oscillate between freezing conditions one part of the year and temperate conditions during the other part. The same could be said of wood frogs.
Title: Re: Will something like Tardigrades be found on other worlds?
Post by: puppypower on 16/07/2017 13:26:59
An interesting way to look at Tardigrades is they have evolved capacities for survival, that exceeds normal earth environmental parameters. This suggests the Tardigrades are not exactly part of the traditional natural selection process, since they have evolved capacities that have little need to be selected, under earth conditions. They developed the capacity to withstand pressure many times more than generated by the deepest oceans. Why select something that will never be needed and then allow this to persist? It would be like selecting longer legged animals in anticipation of a flood millions of year away.

Most of evolution is assumed to involve selection based on tangible and changing earth parameters and not abstractions of possible extreme conditions that may or may not ever occur. This suggests there is a secondary internal potential to evolve that acts separate from the traditional environmental potentials of Darwinian evolution. I would guess this is driven by increasing chemical stability, which would, by default, allow extreme adaptation skills to be approached and acquired.

This also suggest that evolution has goals and milestones; main curve, with the environment acting to place bumps in the main curve. The Tardigrades have made it to the top of their inner curve. This can be explained with water being the main component of life; organics need to lower the potential with the water.