Evolution - Reality and Misconceptions
Discussion
Wiccan of Darkness said:
... a silicon based life form cannot exist as we as carbon based produce CO2 therefore a silicon based life form would produce SiO2 and why this assumption is fundamentally wrong; explore and rationalise how life could develop elsewhere in the universe and what form it might take. For example, there'll be life on mars if there's sulphur in the atmosphere, little green men CAN exist but would die on earth and so on.
That's a good one, I'll give it shot, though my chemistry is very rusty.Since it is oxidation it should still be exothermic, so I'd think possible from that perspective. Sugars are soluble in water, not sure about solvents for Silicon or Silicon compounds. I'd be concerned about would be liberated from the food and what to react it with. We'd need a simple life form or environmental process to make the food. The biggie is that SiO² is a solid not a gas, which rather makes respiration a problem, not impossible but certainly far more problematic for evolution than expelling a gas.
Just a random thought, could it work the other way around, the SiO² is the food. I don't think so because it would require the life to be endothermic, environmental heat maybe, which would make for pretty strange environment. Not really sure about this, but probably not. That about all I've got and were I'd look.
Could Silicon work with RNA/DNA, no idea, but perhaps there could be a facsimile, far beyond my chemistry.
Wiccan of Darkness said:
(Slightly o/t but I have a theory that Jupiter does have a solid core, and a liquid layer on top - but as it's all gas, the temperature and pressure would make it uninhabitable - but it would be due to the pressure and temperature created as gravity pulls the gas inwards source but we don't actually know the answer...)
I think we can be pretty certain that all the gas giants have something solid at the core as a hypothesis, we just need to prove it. I'm sure I've seen something recently about the results from the Juno or Cassini space probes pretty much confirming this for one of them. I'll have a did around and see what I can find.--- addition ---
Like evolution, it seems far more nuanced that it first appears. I think we might have quite a lot to learn about metallic hydrogen. It appear both have some kind of (semi) solid core, but not a 'rocky' molten iron core we might expect.
https://www.space.com/37005-jupiter-fuzzy-core-nas...
https://spaceflightnow.com/2017/10/19/cassini-resu...
Edited by 4x4Tyke on Friday 7th September 17:25
New Scientist have presented a few articles on Evolution in the last couple of weeks and I'll to outline some of the key points. It does keep calling it anti-evolution, in quotes, but I think that is rather a misnomer, if we think of it being fitnesses to the environment it is just evolution.
In our battle with antibiotic resistance we are seeing a return to a fundamental evolutionary thinking. One example that has been a big with virus and has driven this thinking is the triple drug therapy used very effectively against HIV. This is being carried over to bacterial infections, using combinations or alternating antibiotics against resistant strains. This approach is even seeing success with cancer, were some cancers can become resistant to one form of chemotherapy but still remain or become susceptible to combinations or alternating.
There was some really interesting stuff on using phages and CRISPR to break resistance to remove the genes for resistance. It stuck me this approach could also be used to make some infectious agents more benign by their genes that make them dangerous as sometimes happens naturally.
These are paywalled, but well worth the online subscription IMHO.
https://www.newscientist.com/article/mg23931930-20...
Another on the earlier topic of 'alien' life on earth
https://www.newscientist.com/article/mg23931940-40...
In our battle with antibiotic resistance we are seeing a return to a fundamental evolutionary thinking. One example that has been a big with virus and has driven this thinking is the triple drug therapy used very effectively against HIV. This is being carried over to bacterial infections, using combinations or alternating antibiotics against resistant strains. This approach is even seeing success with cancer, were some cancers can become resistant to one form of chemotherapy but still remain or become susceptible to combinations or alternating.
There was some really interesting stuff on using phages and CRISPR to break resistance to remove the genes for resistance. It stuck me this approach could also be used to make some infectious agents more benign by their genes that make them dangerous as sometimes happens naturally.
These are paywalled, but well worth the online subscription IMHO.
https://www.newscientist.com/article/mg23931930-20...
Another on the earlier topic of 'alien' life on earth
https://www.newscientist.com/article/mg23931940-40...
a slight aside but one i find interesting is how "we" didn't evolve more quickly than we have especially over the last 10-20 thousand years.
we have moved so fast over the last 100 years it seems almost inevitable that we will continue to do so.
my question is why did it take so long - point in question. the Pyramids in Egypt. massive, complex, technological constructions, yes labour intensive but no doubt huge feats of science and knowledge at the time.
I wonder why this wasn't a driver for more swift technology advancements and we would have got to where we are now but say a thousand years earlier?
what happened to that knowledge base and technological drive - did they finish the pyramids, sit back and say "right, lets have a wine, our work is done here?"
we have moved so fast over the last 100 years it seems almost inevitable that we will continue to do so.
my question is why did it take so long - point in question. the Pyramids in Egypt. massive, complex, technological constructions, yes labour intensive but no doubt huge feats of science and knowledge at the time.
I wonder why this wasn't a driver for more swift technology advancements and we would have got to where we are now but say a thousand years earlier?
what happened to that knowledge base and technological drive - did they finish the pyramids, sit back and say "right, lets have a wine, our work is done here?"
Nom de ploom said:
a slight aside but one i find interesting is how "we" didn't evolve more quickly than we have especially over the last 10-20 thousand years.
we have moved so fast over the last 100 years it seems almost inevitable that we will continue to do so.
my question is why did it take so long - point in question. the Pyramids in Egypt. massive, complex, technological constructions, yes labour intensive but no doubt huge feats of science and knowledge at the time.
I wonder why this wasn't a driver for more swift technology advancements and we would have got to where we are now but say a thousand years earlier?
what happened to that knowledge base and technological drive - did they finish the pyramids, sit back and say "right, lets have a wine, our work is done here?"
The drive to carry out such projects dissipates as culture and priorities change. We have seen this scenario repeat itself over and over again - whether it's pyramids in Ancient Egypt, great cathedral building in the Middle Ages or launching Saturn Vs to the moon in the 1960s and 70s.we have moved so fast over the last 100 years it seems almost inevitable that we will continue to do so.
my question is why did it take so long - point in question. the Pyramids in Egypt. massive, complex, technological constructions, yes labour intensive but no doubt huge feats of science and knowledge at the time.
I wonder why this wasn't a driver for more swift technology advancements and we would have got to where we are now but say a thousand years earlier?
what happened to that knowledge base and technological drive - did they finish the pyramids, sit back and say "right, lets have a wine, our work is done here?"
Eric Mc said:
The drive to carry out such projects dissipates as culture and priorities change. We have seen this scenario repeat itself over and over again - whether it's pyramids in Ancient Egypt, great cathedral building in the Middle Ages or launching Saturn Vs to the moon in the 1960s and 70s.
I think the motivation for building cathedrals was that the building process was seen as a worthwhile activity in itself, rather than just wanting a cathedral. Perhaps space exploration in general is a closer analogy.I've just finished reading Julian Jaynes Bicameral Mind and the Origin of Consciousnesses. I'm not sure I buy the bicameral mind hypothesis (consciousness through auditory hallucinations for example) , but I do wonder whether some elements of the hypothesis have got some legs, specifically the way psychological changes are needed to move from a small group way of living to larger societies.
Richard Dawkins said the Julian Jaynes work was either complete rubbish or a work of absolute genius.
Richard Dawkins said the Julian Jaynes work was either complete rubbish or a work of absolute genius.
ash73 said:
Nom de ploom said:
I wonder why this wasn't a driver for more swift technology advancements and we would have got to where we are now but say a thousand years earlier?
Slavery; the last thing the Romans wanted was a third of the population having more time on their hands.We sometimes hear the term Social Darwinism, but we need to be cautious not to conflate it with Darwinian Evolution.
While I do think the mechanisms are very similar and it does need to be studied, darwinism as a theory is proven in the context of the evolution of species we cannot say the same thing for social evolution.
What we see is a mechanism, of variation, selection and perhaps even periods of punctuated equilibrium as new idea distribute before leading to a step change.
In the context of the great Pyramids, these did require a degree of social development, division of Labour; food production, stone quarrying, transport, middle management and a visionary of sorts, be it a priest or aristocratic class.
While I do think the mechanisms are very similar and it does need to be studied, darwinism as a theory is proven in the context of the evolution of species we cannot say the same thing for social evolution.
What we see is a mechanism, of variation, selection and perhaps even periods of punctuated equilibrium as new idea distribute before leading to a step change.
In the context of the great Pyramids, these did require a degree of social development, division of Labour; food production, stone quarrying, transport, middle management and a visionary of sorts, be it a priest or aristocratic class.
4x4Tyke said:
Wiccan of Darkness said:
... a silicon based life form cannot exist as we as carbon based produce CO2 therefore a silicon based life form would produce SiO2 and why this assumption is fundamentally wrong; explore and rationalise how life could develop elsewhere in the universe and what form it might take. For example, there'll be life on mars if there's sulphur in the atmosphere, little green men CAN exist but would die on earth and so on.
That's a good one, I'll give it shot, though my chemistry is very rusty.Since it is oxidation it should still be exothermic, so I'd think possible from that perspective. Sugars are soluble in water, not sure about solvents for Silicon or Silicon compounds. I'd be concerned about would be liberated from the food and what to react it with. We'd need a simple life form or environmental process to make the food. The biggie is that SiO² is a solid not a gas, which rather makes respiration a problem, not impossible but certainly far more problematic for evolution than expelling a gas.
Just a random thought, could it work the other way around, the SiO² is the food. I don't think so because it would require the life to be endothermic, environmental heat maybe, which would make for pretty strange environment. Not really sure about this, but probably not. That about all I've got and were I'd look.
Could Silicon work with RNA/DNA, no idea, but perhaps there could be a facsimile, far beyond my chemistry.
otolith said:
Hmm, I'm not sure how feasible a silicon based life form would be in other respects, but it's worth keeping in mind that there are carbon based life forms on Earth which use various inorganic substrates for energy. A silicon based organism might not get its energy by oxidising silicon compounds.
I kind of alluded to that with endothermic comment but my (bio)chemistry is far too weak to really delve into it. It was interesting question and I hoped my poor response might trigger some interesting posts where I could learn something.4x4Tyke said:
otolith said:
Hmm, I'm not sure how feasible a silicon based life form would be in other respects, but it's worth keeping in mind that there are carbon based life forms on Earth which use various inorganic substrates for energy. A silicon based organism might not get its energy by oxidising silicon compounds.
I kind of alluded to that with endothermic comment but my (bio)chemistry is far too weak to really delve into it. It was interesting question and I hoped my poor response might trigger some interesting posts where I could learn something.Silicon based biochemistry is possible, it would probably be limited to very simple forms of life. It would also need to be in an environment that is much hotter than you would ordinarily find the liquid water also required for the chemistry. I guess you could imagine a high pressure very hot environment that could have the potential to produce silicon based lifeforms.
Ironically, as far as this thread goes, the greatest threat to silicon based lifeforms coming into existence would be natural selection itself. Carbon based life, either within the extreme environment, or within the wider biosphere would out compete the silicon based life forms.
Ironically, as far as this thread goes, the greatest threat to silicon based lifeforms coming into existence would be natural selection itself. Carbon based life, either within the extreme environment, or within the wider biosphere would out compete the silicon based life forms.
Wiccan of Darkness said:
I got in to a bit of a dispute with the alpaca club of GB some years back after I personally valued a "prize-winning" alpaca with a £40k price tag as being worth as much as a fart. I was met with the 'oh you don't know what you're talking about' attitude from some snotty woman who knew everything.
Anyhoo.... the planetary nebulus. One of the first assignments I give my students is about aliens. It gets them thinking about how life can evolve in different mediums. It's because as a sprout I saw an X files show where some guy had a silicon based fungus growing in his lungs and it left a load of sand; the purpose of the assignment is to explore the armchair trekkies view that a silicon based life form cannot exist as we as carbon based produce CO2 therefore a silicon based life form would produce SiO2 and why this assumption is fundamentally wrong; explore and rationalise how life could develop elsewhere in the universe and what form it might take. For example, there'll be life on mars if there's sulphur in the atmosphere, little green men CAN exist but would die on earth and so on.
Organisms are quite adept at retaining DNA they don't need. Pile up all your post from your life, and it'll have bank statements, mortgage statements, bills, receipts, work stuff, postcards etc. From all your post, I can determine who you are. But there's more junk mail than decent mail. It's the same with DNA. Yes, we have 46 chromosomes. A life time of mail. It has an awful lot of junk in there, too.
If we're this evolved, with 46 chromosomes, I want you all to imagine how "evolved" something is with, say, 80 chromosomes?
If a human is formed from 46 chromosomes, then what on earth do you get with 1260 chromosomes? Some giant mutant that communicates with brain waves and shoots lasers from its eyes?
Not quite.. A fern does, though
SOunds like one of those twits that goes to crufts.Anyhoo.... the planetary nebulus. One of the first assignments I give my students is about aliens. It gets them thinking about how life can evolve in different mediums. It's because as a sprout I saw an X files show where some guy had a silicon based fungus growing in his lungs and it left a load of sand; the purpose of the assignment is to explore the armchair trekkies view that a silicon based life form cannot exist as we as carbon based produce CO2 therefore a silicon based life form would produce SiO2 and why this assumption is fundamentally wrong; explore and rationalise how life could develop elsewhere in the universe and what form it might take. For example, there'll be life on mars if there's sulphur in the atmosphere, little green men CAN exist but would die on earth and so on.
Organisms are quite adept at retaining DNA they don't need. Pile up all your post from your life, and it'll have bank statements, mortgage statements, bills, receipts, work stuff, postcards etc. From all your post, I can determine who you are. But there's more junk mail than decent mail. It's the same with DNA. Yes, we have 46 chromosomes. A life time of mail. It has an awful lot of junk in there, too.
If we're this evolved, with 46 chromosomes, I want you all to imagine how "evolved" something is with, say, 80 chromosomes?
If a human is formed from 46 chromosomes, then what on earth do you get with 1260 chromosomes? Some giant mutant that communicates with brain waves and shoots lasers from its eyes?
Not quite.. A fern does, though
Have you read anything by Jack Cohen? He helps sci-fi writers design proper aliens for stories and things, not star trek stuff.
THe thing about chromosomes is interesting. I've read a few things that reckon the gut bacteria is what makes us who we are, we are our gut, and our gut is what we eat.
Now where's that gold.
Nimby said:
Try this, and the rest of the Wiki entry.
That was interesting, took me a while to get through it all and probably only digested 
a fraction of it.If we can go back to the discussion of chromosomes for a while, one thing I've wondered about, that is beyond my biology, though I know the basic theory of genetic probabilities.
Downs people have an extra chromosome, 47 in total. Now if two downs people have a child and given the normal way chromosomes combine. Does that mean they get a mixture of genes from the full 47 chromosome, so still downs, or does it mean genetically (if we gloss over spontaneous miscarriage risk for the moment) :
25% chance of 46 chromosome fetus
50% chance of 47 chromosomes fetus (25% from each parent)
25% chance of 48 chromosome fetus
ash73 said:
Interesting study by Stoeckle and Thaler
Would you adam 'n eve it:
https://www.dailymail.co.uk/news/article-6424407/E...
What it really means:
https://phys.org/news/2018-05-gene-survey-reveals-...
The actual paper:
https://phe.rockefeller.edu/news/wp-content/upload...
Isn't that just mitochondrial Eve? Hardly new.Would you adam 'n eve it:
https://www.dailymail.co.uk/news/article-6424407/E...
What it really means:
https://phys.org/news/2018-05-gene-survey-reveals-...
The actual paper:
https://phe.rockefeller.edu/news/wp-content/upload...
OK, a bit pop-science but I enjoyed this Joe Rogan / William von Hippel chat on human evolution - remember he's a phychologist, not an anthropologist per se.
https://www.youtube.com/watch?v=7Dtv8ibI1vk
https://www.youtube.com/watch?v=7Dtv8ibI1vk
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