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Author | Topic: Question on evolutionary Rates | |||||||||||||||||||||||||||||||||
ICANT Member Posts: 6769 From: SSC Joined: Member Rating: 1.5 |
QUESTION:
If age of Earth = 4.6 billion years, Single cell life = 3.8 billion years ago, Multicellular life = 1.5 billion years ago, Using 200,000 years per speciation that would = 11,500 speciations to get from single cell to multicell life forms. Frank Stephenson writes:
...www.gly.fsu.edu.... Through dating analysis, he and his colleague have shown that the forams could produce a whole new species in as little as 200,000 years -- speedy by Darwinian standards. That leaves 7500 speciations to get to modern man, from Eukaryotic Cells. How is it possible for Modern man to evolve from Eukaryotic Cells in only 7500 speciations when it took 11,500 to go from single cell to Eukaryotic Cells? Edited by AdminNosy, : Taking the liberty of changing the thread title.
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AdminNosy Administrator Posts: 4754 From: Vancouver, BC, Canada Joined: |
Thread moved here from the Proposed New Topics forum.
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cavediver Member (Idle past 3643 days) Posts: 4129 From: UK Joined: |
Hi ICANT I must admit this is not my field - but I love the question so can't help but butt in before the experts arrive
I'm simply in awe of the fact that it took the best part of 2 billion years to go from Pro. to Eukaryotic cell... blows my mind. But it is a mistake to think it was the Pro.s evolving their way towards the Eu.s What was changing was the Earth - it was two billion years of 'terra'-forming the atmosphere from a carbon-dioxide rich environment to an oxygen-rich environment by the photo-synthesising prokaryotes. The oxygen was a blessing and a curse - it is highly toxic (something us divers are only too aware - killed my best friend!) and rising levels would have decimated the existing life... but some would have evolved to take advanatge of the huge energy benefit oxygen-use can bring leading the way to multi-cellular and Eurkarotic life. So primitive life itself paved the way for the more advanced life - work of genius if you ask me Anyway, I've embarressed myself enough here already. When you are ready to offer your questions on the beginnings of the universe, fine-tuning, and any other cosmological issues, come and find me. That's my field...
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RAZD Member (Idle past 1405 days) Posts: 20714 From: the other end of the sidewalk Joined: |
How is it possible for Modern man to evolve from Eukaryotic Cells in only 7500 speciations when it took 11,500 to go from single cell to Eukaryotic Cells? Not all Eukaryotic Cells life is multi-cellular. Eukaryotic Cells first evolved as single cell life forms, about 2 billion years ago (although it can be - and is - argued that this was developed by one cell being absorbed inside another to create a new kind of single cell). Then it only took 0.5 billion years to form the first mutlicellular life. But why is this (change over time) a problem? Look at those Eukaryotic Cells and see if there is any substantial difference between them: what is inside a single cell life cell is inside the multi-cell life cell. The change from original cell form to Eukaryotic Cells is actually much more significant, as this adds several features to make these "modern" cells. Think of the time it takes a child to learn to stack one block on top of another, and then the time needed to make a stack 3, 4, 5 blocks high. All multicellular life develops from single cells, it's just a matter of stacking the cells up to make a multicellular life. What you really need to look at is the formation of the basic body plan of an interactive multicellular life as opposed to one that is a group of similar function cells. Once you have a basic body plan then all you need is variations on a theme.
That leaves 7500 speciations to get to modern man, from Eukaryotic Cells. Don't confuse the existence of man with the need for man to be a result. Functionally man is no different than the first mammal, which is functionally no different than the first reptile, which is ... etc. And don't confuse a minimum with average or expect evidence from one example to apply to others: the evidence from the forams only applies to the forams that stayed forams (the data group of the study), so there could be undocumented speciation events where forams became no-longer-forams (perhaps they ditched their shells eh?). We also do not have any figures for speciation rates when sexual selection is a factor. The evidence from human history is that this can significantly alter the rate of mutation selection -- just the difference in fixed genes between man and chimps shows this. The more you break the development over time scale down the more you will see that only small steps are needed. Hope that helps. Enjoy. compare Fiocruz Genome and fight Muscular Dystrophy with Team EvC! (click) we are limited in our ability to understand by our ability to understand RebelAAmericanOZen[Deist ... to learn ... to think ... to live ... to laugh ... to share.
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Chiroptera Inactive Member |
quote: Actually, the meaning of "species" is pretty ill-defined for organisms that do not reproduce sexually. Where do you get the "200,000 years per speciation" from? -
quote: I dunno. How was it that it took the Hebrews 40 years to get from Egypt to Canaan, when the distance is less than a couple of hundred miles? Especially when someone can walk that distance in about a month. Actually, if their god makes better pancakes, I'm totally switching sides. -- Charley the Australopithecine
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crashfrog Member (Idle past 1467 days) Posts: 19762 From: Silver Spring, MD Joined: |
That leaves 7500 speciations to get to modern man, from Eukaryotic Cells. You're confusing exponential growth with linear growth. It's not one new species every 200,000 years; it's every species produces a new species every 200,000 years. (Assuming this model is correct. It's probably not accurate to apply conclusions from Foramanifera to all species.) Go back and do the math with the correct calculations - have the number of species double every 200,000 years over 3.8 billion years. I think you'll find it's way, way more than you could possibly imagine; and indeed, way, way more species than have been known to exist. (Because your model doesn't take into account extinction.)
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fallacycop Member (Idle past 5520 days) Posts: 692 From: Fortaleza-CE Brazil Joined: |
How is it possible for Modern man to evolve from Eukaryotic Cells in only 7500 speciations when it took 11,500 to go from single cell to Eukaryotic Cells? Since single cell Eukaryotic life forms are genetically closer to humans (and other eukariotic life forms) then they are to procariotic single cell life forms, You wouldn`t have a paradox even if you assumed a linear evolutionary rate through all evolutionary history, which in itself is already a shaky assumption to say the least Edited by fallacycop, : typo
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Chiroptera Inactive Member |
Heh. That is a good point. Biologically, there isn't much difference between a human and a worm, and not much more difference between a worm and a collar flagellate.
On the other hand, biochemically, a bacterium is very, very, different from a collar flagellate. Actually, if their god makes better pancakes, I'm totally switching sides. -- Charley the Australopithecine
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AdminNosy Administrator Posts: 4754 From: Vancouver, BC, Canada Joined: |
I should have changed the title at approval time. I hope you don't mind ICANT but a thread can not be a catch all for any "questions". Let's do this to help keep us focussed.
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RAZD Member (Idle past 1405 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Actually, the meaning of "species" is pretty ill-defined for organisms that do not reproduce sexually. Where do you get the "200,000 years per speciation" from? Foraminifers are sexual and asexual, but not conscious (so sexual selection not a factor). The rate comes fromarticle 8 quote: compare Fiocruz Genome and fight Muscular Dystrophy with Team EvC! (click) we are limited in our ability to understand by our ability to understand RebelAAmericanOZen[Deist ... to learn ... to think ... to live ... to laugh ... to share.
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Chiroptera Inactive Member |
quote: If MartinV starts polluting this thread, I will blame you. Actually, if their god makes better pancakes, I'm totally switching sides. -- Charley the Australopithecine
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ICANT Member Posts: 6769 From: SSC Joined: Member Rating: 1.5 |
Where do you get the "200,000 years per speciation" from? ...www.gly.fsu.edu.... I was using the fastest time the foraminiferan could produce a new species which was fast compared with Darwinian standards. There was one species that hadn't changed in 500,000 years. Should have taken 10 days to make the journey.
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ICANT Member Posts: 6769 From: SSC Joined: Member Rating: 1.5 |
No problem just as long as I can learn.
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ICANT Member Posts: 6769 From: SSC Joined: Member Rating: 1.5 |
so there could be undocumented speciations events where forams became no-longer-forams (perhaps they ditched their shells eh?). You mean to tell me that these young scientist did not look for forams that could have been used as gap fillers. Their research was at a real vocal point with YEC's, and other creationist. If they could have provided a detailed trail with the formas forking off and becoming some other family of creature they would have been heros.
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ICANT Member Posts: 6769 From: SSC Joined: Member Rating: 1.5 |
Hi crash,
It's not one new species every 200,000 years; it's every species produces a new species every 200,000 years. I know if you started with just one specie in 200,000 years you would have 2. In another 200,000 you would have 4 then 8 then 16 etc. What I am saying at the 200,000 year rate you could only have 7500 levels. Think of it as a set of door steps where you would have steps running off in all directions but you would only have 7500 levels of steps. I don't know but I think the rate would be slower as the species got more complicated. Then you had all the extinction events. Then when they started to mate you have the added problem of mating. Now you have a major problem you can't have all males or all females you have to have one of each. That problem had to be solved along the way somewhere. But if you say OK forget all those problems we had a new species every 200,000 years you would have the 7500 levels.
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