stem cells/ adapting to new worlds/ still human?

[sunshaker]

After a previous thread got closed "Earth as a living organism", I thought I would look more into the beginning of life on earth.

 

 

The primordial soup theory suggests that life began in a pond or ocean as a result of the combination of metals, gases from the atmosphere and some form of energy, such as a lightning strike, to make the building blocks of proteins which would then evolve into all species.

The new research shows how small pockets of a cell - known as mitochondria - continue to perform similar reactions in our bodies today.

These reactions involve iron, sulfur and electro-chemistry and are still important for functions such as respiration in animals and photosynthesis in plants.

I see this "soup" proteins/rna/dna as earths stem cells, containing all the building blocks for life that was to come,

 

But there is also the theory that life began near heated sea vents

 

 

University College London. "We present the alternative that life arose from gases (H₂, CO₂, N₂, and H₂S) and that the energy for first life came from harnessing geochemical gradients created by mother Earth at a special kind of deep-sea hydrothermal vent -- one that is riddled with tiny interconnected compartments or pores."

It seems to be at the moment take your pick which you prefer,

 

 

Whichever one or neither still leaves us with life "evolved on earth", Can life adapt to new worlds?.

 

 

By analyzing the effects of weightlessness on the cellular level, scientists in Australia now believe they have pinpointed the roots of its harmful consequences. Microgravity apparently tampers with stem cells, which all other cells originate from. Stem cells normally act as a repair system for the body by replenishing its tissues. Stem cells showed vast differences on the molecular level, with 64 percent of their proteins differing from those grown under normal gravity. Specifically, these microgravity-exposed cells generated more proteins that degrade bone and fewer proteins with antioxidant effects. Antioxidants protect against reactive oxidants that can damage DNA.


Read more at: http://phys.org/news/2010-10-stem-cells.html#jCp

 

What I was thinking if we do start colonizing other planets,

And stem cells react differently to different gravities and environments from the word go, There will come a time when the human race will be as diverse as we already imagine aliens to be from us.

 

I can imagine there will be many deformities in the beginning, But over generations the stem cells will adapt/evolve to their new environments/planets.

So in billions of years from now the human race could populate the universe,

Earth would be forgotten, And none of these races would ever know they where once human.

 

 

I know we can trace back dna thousands perhaps millions of years if we had samples, But none of this dna has ever left earth, And been subjected to alien environments.

 

 

After these changes/time scales could their Dna still point to a common ancestor ? Or be changed beyond recognition?

 

Or would their dna evolve to match the life that may already be on these worlds?

Edited October 21, 2014 by sunshaker

[sunshaker]

I was reading how moving environments can effect genes/dna, Like this study done with bees.

Half european honey bees, Half african killer bees

They took about 250 of the youngest bees from each hive and placed them in the other hive, At the end of 6 weeks, the bees where collected and tested.

 

the results were stunning.” For the bees that had been kidnapped, life in a new home had indeed altered the activity of “whole sectors” of genes. When their gene expression data was viewed on the cards alongside the data for groups of bees raised among their own kin, a mere glance showed the dramatic change. Hundreds of genes had flipped colors. The move between hives didn’t just make the bees act differently. It made their genes work differently, and on a broad scale.

What’s more, the cards for the adopted bees of both species came to ever more resemble, as they moved through life, the cards of the bees they moved in with. With every passing day their genes acted more like those of their new hive mates (and less like those of their genetic siblings back home). Many of the genes that switched on or off are known to affect behavior; several are associated with aggression. The bees also acted differently. Their dispositions changed to match that of their hive mates. It seemed the genome, without changing its code, could transform an animal into something very like a different subspecies.http://www.psmag.com/navigation/health-and-behavior/the-social-life-of-genes-64616/

These changes happened within 6 weeks, I wonder if this is because the stem cells are more active in the young.

But if this can happen in bees in a few weeks, I wonder about the long term effects on humans when we leave earth.

Can evolution work faster than we think given the right circumstances/environments?

[Endy0816]

Code wise it probably already did switch once(RNA -> DNA). Though we still utilize RNA as well as DNA. If there was coding scheme before RNA though, we might indeed not recognize a species still employing it as being related.

 

As far as stem cells go, there is an alternative as you can create spin and simulate gravity that way. Radiation will likely be the biggest issue. Mostly depends on what happens in anticancer research.

 

The Bee article is an example of a phenotype change, rather than genotype.

 

You really do not want to have to rely on evolution to solve your problems. The application of your intelligence is often the better option. May not be as refined as what evolution could pull off, but you'll have a solution faster than evolution would allow and without the death and suffering.

Edited October 21, 2014 by Endy0816

[sunshaker]

Code wise it probably already did switch once(RNA -> DNA). Though we still utilize RNA as well as DNA. If there was coding scheme before RNA though, we might indeed not recognize a species still employing it as being related.

 

 

 

It is why i was wondering whether dna would change beyond recognition or still be able to be traced back to a common earth ancestor. Would there be something about earth that always remains some where in dna,

 

 

As far as stem cells go, there is an alternative as you can create spin and simulate gravity that way. Radiation will likely be the biggest issue. Mostly depends on what happens in anticancer research.

but colonizing planets I do not think simulating gravity will always be practical, It will be a case of adapting to each planets gravity/radiation, I suppose at first(generation or two) it will be done with bio engineering, but then left to natural means. Which would mean stem cells changing/adapting to new environment in turn changing the human form..

 

 

 

The Bee article is an example of a phenotype change, rather than genotype.

Natural selection affects the genetic structure of a population indirectly via the contribution of phenotypes. Without phenotypic variation, there would be no evolution by natural selection. Wiki.

which leads me to believe we can drastically speed up natural selection by sudden changes of environment.

 

 

You really do not want to have to rely on evolution to solve your problems. The application of your intelligence is often the better option. May not be as refined as what evolution could pull off, but you'll have a solution faster than evolution would allow and without the death and suffering.

I am thinking many thousands of years, even with the "application of intelligence" evolution will still take over in the long term,

 

Perhaps we are lost colonists (Mitochondrial Eve) from a race that done this millions of years ago, who wanted a simple way of life , and there are no missing links, just a missing craft that brought us here. And our dna adapted to earth to become what it is now.

 

Them little grey aliens that some believe are visiting us, may be our distant ancestors keeping a eye on us .

[Endy0816]

Anything you code in X language you can code in Y provided they are similar enough and a means of translation exists. We found retroviruses which can go RNA -> DNA. So we know translation is possible because they do it.

 

If we didn't have retroviruses or didn't know about the process we would only have guessing.

 

The mitochondria are widespread amongst the world's species and the mtDNA and nuclear DNA meshed together. Our relationship with plants is really what you would want to look into. Gives a good sense of the broad timeline of events.

 

If there was any sort of seeding it would have needed to have been in what we generally term the primordial soup period.

 

All your cells have the same DNA. Phenotypes are the result of expressing basically different parts of that DNA. The stem cells wouldn't be evolving themselves and this is a good thing as them evolving we call cancer. The DNA they and the rest of your cells use can evolve but the stem cell itself hopefully not.

 

Anyways gotta sleep sometime. Come to think of it I can blame evolution for that one too.