Life on other planets

[Nokton]

The snowball effect on our planet occured 600 mil years ago.
It has been suggested that without it, evolution not got a kickstart.
How many planets out there got a moon, and seen the same climate
change as ours. We are special, but nothing like us is in reason.
nokton

[Blue Fire]

Yes, I am inclined to think that life on earth is unique in that life on extra solar planets is not likely to be anything like what we are familiar with. On the other hand, I do think it is possible that if life is discovered on other planets in our own solar system (or other moons of those planets), it may indeed turn out to be relatively similar at least on the microbial scale. This may be a consequence of an increasingly popular theory that the "seeds" of life here on Earth may have come from asteroids, comets, and/or other Kuiper belt objects, etc., and thus similar seeds of life were sown elsewhere in our solar system and may have at least a common origin or starting point. I think that all bets are off though as far as lifeforms higher than microbes are concerned.

[Nokton]

Thanx Blue your response. Agree we have a unique set of circumstances
on our planet that has been favourable to life and to evolution, despite
our planets growling at it's interior. The growling caused so many extinctions, but life adapted and changed to cope with it.
It is not life on other planets that concerns me, more, it is the capacity
for it's evolution. Important parameters must be met, not least a hard
radiation block from the local sun, as we have in the ozone layer, orbital
stability provided by a moon such as ours, you know the rest.
But, with so many stars out there, who knows? And given our track record of one advanced race in contact with a less advanced one,
who knows, they may have laws about contact.........
Nokton

[Blue Fire]

Originally Posted by Nokton

. . . despite
our planets growling at it's interior. The growling caused so many extinctions, . . .

"growling"? What is this growling you speak of? There have been asteroid impacts, possibly in combination with volcano activity, that have been postulated as the cause for the two greatest mass extinctions. But this "growling" you say has caused so many extinctions has me confused. What do you mean by it? Can you be more specific regarding the particular "growling" you speak of and what specific extinctions you are referring to? Thanks!

[Nokton]

Hi Blue,
Am refering to the changing of the earth by continental
drift, volcanic activity, weather patterns and ice ages, hence my
description, a grumbling earth.
There is no evidence that co relates an asteroid impact with a mass extinction. The dinosaurs? The basalt flood plains spewed out so much toxic gas they were already doomed long before that struck.
Life, Blue, has always been about adaptation to a changing environment,
that environment has always been determined by a grumbling earth.
As an aside Blue, global warming. Once in time, the arctic and antarctic
were total forest, for millions of years. There must be vast reserves of oil
and gas, not to mention millions af acres of arable land free of perma frost, may be, global warming scenario just dealt with the downside......
Nokton

[Blue Fire]

Originally Posted by Nokton

. . .
There is no evidence that co relates an asteroid impact with a mass extinction. . . .

Actually, dear friend, There is a great deal of evidence for an asteroid impact being responsible for a couple of mass extinctions: SPACE.com -- The Five Worst Extinctions in Earth's History

Cretaceous-Tertiary extinction, about 65 million years ago, probably caused or aggravated by impact of several-mile-wide asteroid that created the Chicxulub crater now hidden on the Yucatan Peninsula and beneath the Gulf of Mexico.

As the article states, there are some that argue for other causes, but to my knowledge this asteroid impact is the most widely held reason for the extinction, perhaps aggravated by volcanic activity. Also keep in mind that this article is at least 7 years old. Note this fact for the quote below as well.

Permian-Triassic extinction, about 251 million years ago. Many scientists suspect a comet or asteroid impact, although direct evidence has not been found. Others believe the cause was flood volcanism from the Siberian Traps and related loss of oxygen in the seas. Still others believe the impact triggered the volcanism and also may have done so during the Cretaceous-Tertiary extinction. The Permian-Triassic catastrophe was Earths worst mass extinction, killing 95 percent of all species, 53 percent of marine families, 84 percent of marine genera and an estimated 70 percent of land species such as plants, insects and vertebrate animals.

However, recently there is evidence that an asteroid impact was a major player in this extinction - there is ongoing investigation into an impact zone in Australia that correlates with the time of this extinction. To my knowledge, this impact could very well have triggered much volcanism as well.

I should probably have done more supporting research, and I'm sure I could find much more updated info supporting the asteroid impact theory, but just now I am pressed for time and I'm being lazy.

[Nokton]

Hi Blue,
Thanx your reply. Conjecture is no substitute for truth and fact.
OK, mass extinctions occured at the end of the Palaeozoic era, but there is no substantive data as to why. Then the Permo-Triassic, and life made a comeback in a big way. My point was, and is, so far, life has a capacity for survival despite serious setbacks. What drives that, is what concerns me deeply. Am not a religious person Blue, I abhor religion. So looking at a theory of mine that involves a program embedded in the genetic code.
Nokton.