Evolution - Reality and Misconceptions
Discussion
Thought I'd start a thread here for those who want to discuss how evolution works i.e. what changes to an organism are due to biological evolution ( i.e. genetics) or other, sociological, factors.
There was a strand developing on this in the "Trump" thread in the news section which is really not appropriate in that forum.
There was a strand developing on this in the "Trump" thread in the news section which is really not appropriate in that forum.
It's nice to see a thread develop with genuine knowledge at its core. I don't have a huge amount of knowledge in this area but I have read lots of books on the history of life on earth (stemming from a life long interest in dinosaurs).
Has anybody read the books written by the late Jay Gould? I always found them interesting.
Has anybody read the books written by the late Jay Gould? I always found them interesting.
Toltec said:
The title does contain many of the same letters though so perhaps some ruling could be interpreted from that, just so believers could know what to think about them.
Then they could have endless discussions and schisms on whether all human propelled wheeled vehicles were covered, if only two wheels were canon or indeed if ebikes were anathema.
Sorry, you may think this is off topic, but blame evolution for giving me a brain that works this way not me.
I could suggest that your brain could be an indicator of an evolutionary dead end.Then they could have endless discussions and schisms on whether all human propelled wheeled vehicles were covered, if only two wheels were canon or indeed if ebikes were anathema.
Sorry, you may think this is off topic, but blame evolution for giving me a brain that works this way not me.
TwigtheWonderkid said:
The bible mentions nothing that wasn't know to Middle Eastern man 2000 years ago. Even stuff that was around, like glaciers, polar bears, armadillos and the Northern Lights don't get a look in. You could almost begin to think it was written by Middle Eastern man.
Amazing deduction.That is my understanding too. Indeed, in its early history, the earth's surface was far too hot for liquid water to be able to remain liquid.. Indeed, there may have been periods where heavy rainfall vapourised before it hit the surface.
The question as to where the earth's water originated is not fully understood. It is thought that it is a combination of water molecules and/or the constituents of water (hydrogen and oxygen) being chemically bound in the rocks that made up the early earth and latter "top-ups" being provided by cometary and asteroidal/meteoritic impacts.
Whatever the mechansim, no liquid water could be sustained until the earth's surface had cooled down to the point where vapourisation would no longer be a serious issue.
The question as to where the earth's water originated is not fully understood. It is thought that it is a combination of water molecules and/or the constituents of water (hydrogen and oxygen) being chemically bound in the rocks that made up the early earth and latter "top-ups" being provided by cometary and asteroidal/meteoritic impacts.
Whatever the mechansim, no liquid water could be sustained until the earth's surface had cooled down to the point where vapourisation would no longer be a serious issue.
Derek Smith said:
It's not universally accepted I think, unless I've missed the consensus. There are adherents for both camps. Whilst the great catastrophes gave rise to lots of new species and killed off any number, these are few and far between. The movement of the continents, on the other hand, is rather pedestrian - and that's over-rating it - so the changes that gave rise to are slower.
There is/was an argument that the dinosaurs, at least a number of them, were dying out due to climate change at the time of tunguska event. Their departure was hurried, like an unwelcome guest in the wee small hours after a party.
I've been reading a report in New Scientist, entitled Outsmarting evolution. I'll have to read it again as it takes a long while for things to sink in with me, but whilst its arguments are interesting and logical, come the next tunguska, all will be for nowt it seems to me.
Beating evolution is a bit like believing you are beating gravity by being in an aeroplane. Sooner or later it will have to come back down to Earth.
The Tunguska Event is a recent (fairly minor) impact - 1908 - and has nothing to do with dinosaur extinction.There is/was an argument that the dinosaurs, at least a number of them, were dying out due to climate change at the time of tunguska event. Their departure was hurried, like an unwelcome guest in the wee small hours after a party.
I've been reading a report in New Scientist, entitled Outsmarting evolution. I'll have to read it again as it takes a long while for things to sink in with me, but whilst its arguments are interesting and logical, come the next tunguska, all will be for nowt it seems to me.
Beating evolution is a bit like believing you are beating gravity by being in an aeroplane. Sooner or later it will have to come back down to Earth.
I presume you mean the Chixilub Event which happened 65 million years ago and seems to have been influential in the disappearance of the dinosaurs - as well as about 75% of other higher animal species that existed at that time.
There is no genuine evidence that it was the asteroid impact of 65 million years ago that actually caused dinosaur extinction - but dinosaurs do disappear from the geological record around 65 million years ago.
That's assuming you don't include birds as dinosaurs - which they increasingly seem to be. In that case, dinosaurs never really did become extinct as they are still around.
The fact that we know there already were obvious "birds" for quite a while before the asteroid impact does not mean that they were not just another type of dinosaur. The recognised first bird found (so far) is Archeoptryx - which is from 150 million years ago. Archeoptryx is really the first dinosaur we found that possessed feather. Because it had feathers, it was classified as a bird. In every other respect, it's a dinosaur. We now know many dinosaurs had feathers.
There is plenty of evidence that birds and dinosaurs are extremely close evolutionary speaking. Indeed, since the mid 1960s and the work of the late John Ostrom and many since, many paeleontoligists have come to the conclusion that there is not really a significant difference between certain dinosaurs and modern birds. Only last week there was a major news story that spoke about new genetic evidence that closens the links even more.
It must be remembered that "dinosaur" is actually a rather incorrect "catch all" name used for what was really a very wide variety of different lines. The two main groups of dinosaurs were the suarischia (lizard hipped) and the ornithisca (bird hipped).
It was spotted quite early on (mid 19th century) in the study of dinosaur physiology that there were two distinct groups which could be identified by their different types of hip structures. One group had a pelvis pretty much the same as modern birds. The other had hips closer to that of modern lizards. We now know that many dinosaurs had the following features -
bird type pelvises
feathers (which we can now see were pretty much identical to modern bird feathers)
hollow bones filled with air sacs
four chambered hearts (something associated with endothermic control of body temperatures - an avian characteristic)
lack of teeth
beaks
All of these characteristics are very typical of birds. Indeed, if some small dinosaurs were still around today, they would probably be classified as flightless birds. Every time I look at a blackbird darting across my lawn, it screams "dinosaur" at me.
I do agree that what caused the "extinction" of the dinosurs (notwithstanding that they aren't all extinct as per above) is attributable to multiple causes with an asteroid impact impact being just one factor rather than the only one.
There is plenty of evidence that birds and dinosaurs are extremely close evolutionary speaking. Indeed, since the mid 1960s and the work of the late John Ostrom and many since, many paeleontoligists have come to the conclusion that there is not really a significant difference between certain dinosaurs and modern birds. Only last week there was a major news story that spoke about new genetic evidence that closens the links even more.
It must be remembered that "dinosaur" is actually a rather incorrect "catch all" name used for what was really a very wide variety of different lines. The two main groups of dinosaurs were the suarischia (lizard hipped) and the ornithisca (bird hipped).
It was spotted quite early on (mid 19th century) in the study of dinosaur physiology that there were two distinct groups which could be identified by their different types of hip structures. One group had a pelvis pretty much the same as modern birds. The other had hips closer to that of modern lizards. We now know that many dinosaurs had the following features -
bird type pelvises
feathers (which we can now see were pretty much identical to modern bird feathers)
hollow bones filled with air sacs
four chambered hearts (something associated with endothermic control of body temperatures - an avian characteristic)
lack of teeth
beaks
All of these characteristics are very typical of birds. Indeed, if some small dinosaurs were still around today, they would probably be classified as flightless birds. Every time I look at a blackbird darting across my lawn, it screams "dinosaur" at me.
I do agree that what caused the "extinction" of the dinosurs (notwithstanding that they aren't all extinct as per above) is attributable to multiple causes with an asteroid impact impact being just one factor rather than the only one.
E34-3.2 said:
Moonhawk said:
Based on the distinct aroma of 'creationism' i'm getting off their posts, I suspect they are trying to conflate this one study with the biblical flood story.
Flood story in the Bible came after earth was populated, no before. Modern humans arrived on the scene very recently i.e. around 1 million years ago at most, so the state of the earth when homo sapiens arrived has nothing to do with how earth has been for most of its history - which goes back 4.5 billion years.
There is no evidence whatsoever that the earth was, at one time, an 100% ocean world.
There is a theory that there may have been at least one geological period where the earth was completely encased in ice (the "snowball earth" theory) which might have happened around the Permian Period about 300 million years ago to 250 million years ago. There is some evidence for this bit it is a bit sketchy and not something that all paeleogeoligists agree on.
There was a "Permian Extinction" event at the end of the Permian Period which was actually a lot more dramatic and devastating than the extinction event at the end of the Cretaceous. The further back in time you go, the more sketchy the geological record and teh fosil record becomes so the harder it is to read what the rocks tell us.
It is highly likely that Continental Drift i.e. the moving of continental plates, began pretty early on in earth's history, not long after the crust solidified.
There is no evidence whatsoever that the earth was, at one time, an 100% ocean world.
There is a theory that there may have been at least one geological period where the earth was completely encased in ice (the "snowball earth" theory) which might have happened around the Permian Period about 300 million years ago to 250 million years ago. There is some evidence for this bit it is a bit sketchy and not something that all paeleogeoligists agree on.
There was a "Permian Extinction" event at the end of the Permian Period which was actually a lot more dramatic and devastating than the extinction event at the end of the Cretaceous. The further back in time you go, the more sketchy the geological record and teh fosil record becomes so the harder it is to read what the rocks tell us.
It is highly likely that Continental Drift i.e. the moving of continental plates, began pretty early on in earth's history, not long after the crust solidified.
There is evidence that there may have been four or five mass extinctions - not just two.
As I said, the problem is that the geological and fossil record becomes harder to read the further back in time you go.
The earth is an extremely dynamic planet from a geological point of view. Convection currents in the mantle cause the mantle to circulate over time and this circulation does two main things - it creates new sea floor (sea floor spreading) and pushes the continental plates about. The plates slide around and crash into each other, creating mountains as they do, and the sea floor dives under the continental margins, where it decscends as part of the convection process, heats up and melts. This process destroys a lot of older rock and any fossil records that may be preserved there.
There are only a few known locations on earth where rocks older than about 3 billion years can be found - usually in the centre of large land masses such as North America, Australia and Africa. The fossil evidence for the oldest known life forms known to have evolved on earth are usually found in these locations.
As I said, the problem is that the geological and fossil record becomes harder to read the further back in time you go.
The earth is an extremely dynamic planet from a geological point of view. Convection currents in the mantle cause the mantle to circulate over time and this circulation does two main things - it creates new sea floor (sea floor spreading) and pushes the continental plates about. The plates slide around and crash into each other, creating mountains as they do, and the sea floor dives under the continental margins, where it decscends as part of the convection process, heats up and melts. This process destroys a lot of older rock and any fossil records that may be preserved there.
There are only a few known locations on earth where rocks older than about 3 billion years can be found - usually in the centre of large land masses such as North America, Australia and Africa. The fossil evidence for the oldest known life forms known to have evolved on earth are usually found in these locations.
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?"
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