The Atheist Delusion (new Christian movie)
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04-11-2016, 12:45 PM
RE: The Atheist Delusion (new Christian movie)
Okay, now that I've got a sense of where that 1-per-year figure is coming from...

... let's talk about what speciation actually is. (And I'm not an expert. If RS jumps in and disagrees with anything I say, listen to him, not me.)

First, that site's hardly a peer-reviewed journal. But that calculation is sensible enough to think that it's within a few orders of magnitude of being correct. (Maybe one per day or one per century.) It's a very rough estimate with a lot of complicating factors unaccounted for, but it's SOMETHING. I'm also not confident in your numbers or sources, but I'll play along.

Even then, there are some challenges.

First, speciation is not an instantaneous result. It's never the case that there is a single species one minute and then, poof, two species the next. It's a long process of gradual differentiation and gray borders that is measured in thousands of generations. When a species is divided into different, isolated pools, they begin to diverge, becoming less homogenous relative to each other. If there are significant environmental pressures, they may diverge more rapidly. Somewhere along the line, the divergence is sufficient that the two populations can no longer viably reproduce. At that point, they are now two distinct species. Speciation is not about growing new features like wings or legs or scales, though some of that (most likely on a smaller scale) can be part of the divergence or part of how the two species can be told apart, and also a consequence of isolation in regions with different survival pressures. It's simply a matter of two populations no longer physically able to interbreed.

So, how do we observe this? Let's say an arachnologist comes across a new type of spider in the Amazon, one that is very similar to other types of spider in the area but lives on a higher level of the rainforest canopy. No one has documented this spider before, which is great news, professionally, for the arachnologist.

But is it a new species, distinct from similar ones lower down in the canopy?

It might have some distinct traits, such as greater tolerance for direct sunlight and a web-weaving style that is more tolerant of winds but less tolerant of falling debris. But these differences do not make it a new species. Such variances exist in the single species of humanity, after all. The question is, can it produce viable offspring with the spiders below?

Well, it doesn't, because they don't mix. But if they did....

... well maybe they wouldn't be attracted to each other. Perhaps web design is part of how they recognize potential mates, perhaps even part of their courtship displays, and the differences in web design keep them from mating. Yet it's entirely possible for web designs to be learned behavior rather than something innate. (I think. I don't actually know if spider brains allow this. But there are certainly similar cases with birdsong and nestbuilding, so it still illustrates the point.) That doesn't make them different species, just standoffish in a cultural way.

Okay, so let's say that two of these spiders try to mate but don't produce viable offspring. What then? Is it just those two spiders that are infertile?

What if only one in a hundred pairings produce viable offspirng, and many of those have severe deformities but could possibly reproduce themselves?

There's no clear, solid line between the state of "one species with two population pools" and "two species". There are clear cases of "it's just one species" and clear cases of "they're two different species", but the area in between is pretty darn vague. And this vague boundary is crossed over thousands of generations, which would mean centuries or millenia for spiders. Pinning down "hey, here's a new species all of a sudden" would be impossible.

So that's the first obstacle in noticing new species evolving: Not having a clear point where the two species are distinct.

But okay, let's say that this newly-discovered spider is, for sure, a new species. Close cousins to the ones a level down in the canopy, sure, but definitely a new species. Is it just newly-discovered, or is it also newly-evolved? How would we tell? Fossils could be too similar to tell the difference between species and wouldn't go far enough back to have fossilized anyway if they were newly evolved... and because fossils are rare, NOT finding fossils could just be evidence of having not looked hard enough, rather than the species being new.

So that's the second obstacle: Not having a way of firmly telling whether a new species is merely newly-discovered or also newly-evolved.

Then there's the problem that most species of life to have lived on Earth, including in the present, are microorganisms. Invisible to the naked eye. Most of them we haven't discovered, and most of the rest we aren't monitoring closely. If we go with your one-per-year number, we'd have a hard time registering most newly-evolved species simply because they're too small to see. There's number 3.

#4: Scientists aren't omniscient. To register each instance of speciation would require continuous (or at least very frequent) monitoring not just of some members of the species, but of ALL population groups of ALL species. This is an impossible task.

#5: Scientists are pretty cautious and may not have called out their observations yet. For example, there appears to have been speciation among a variety of flies that started out as infesting hawthorn trees, but then branched out (no pun intended) to apple trees and then other varieties of fruit trees back in the 19th century. Each variety prefers their own trees and do not appear to interbreed, and this seems like a case of new species. However, the papers on the subject are filled with a cautious attitude. Just because they aren't interbreeding, doesn't mean they CAN'T, and scientists are very, very hesitant to prematurely declare that they can't. And this is a case where there likely HAS been speciation that HAS been observed.

And I'm sure there are more reasons than this as well.

It should be noted that evolutionary science does NOT use observable emergence of new species as a testable prediction of the theory, for many of these reasons. There's just no practical way to go about it.
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04-11-2016, 03:03 PM (This post was last modified: 04-11-2016 03:08 PM by RocketSurgeon76.)
RE: The Atheist Delusion (new Christian movie)
Sorry, I've been working and out running errands all day. Just getting back online.

Well done, Reltzik. Every time I started thinking of an objection, you covered it immediately afterward.

For all the scientific "smart talk" on that website you listed, Dimaniac, it's clear that the author has no good grasp of biology but wants to cherry-pick and make it sound like he does have a good grasp.

As I mentioned and Reltzik explained in detail, speciation does not work in the manner you (and the website) seem to be suggesting. At all. To the point that anyone trying to say we should "expect to see" speciation at that rate is just pulling your chain-- either because they don't know any better or because they think you don't. I won't cover the parts about speciation because Reltzik did a pretty good job.

What the site proposed is an overall calculated average rate of species appearance, based on the rates of change we observe over time. As noted, the old idea (of biology a century ago-- actually, of geology, but biology and geology are closely linked because of fossils), before we had the modern ability to conduct better tests, was that the earth's environment was relatively uniform and stable, and that species evolved gradually into new forms. Thus, if you figured out the rates of change observed and the dates of the rocks those fossils that change are found, you can calculate an average rate of the "appearance" of new forms in the timeline. But it's just a broad average, and does not say anything about the rate at which we should expect things to pop somehow into existence. It ignores that the environment and the earth in general are NOT stable, and that speciation can occur fairly rapidly in cases of founder events, genetic bottlenecks, and a host of other factors related to a disturbance in the equilibrium... that's why researchers eventually coined the term "Punctuated (i.e. interrupted) Equilibria". Even a few of these punctuations in the environmental status quo would be enough to render the average figure useless, in terms of "what we expect to observe". Your dishonest Creationist website neglects to explain any of that-- again, either because they don't understand it or they expect you not to.

The famous "Cambrian Explosion" was not instant, as often depicted, except as compared to the much more stable periods before and after it. You still would have had to wait thousands of years for any visible change to appear in populations, during the most rapid periods of change, and it is only an "explosion" on a geological timescale where what might have taken ten million years in a stable period can now occur in ten thousand years-- that's 1000 times as fast, but still glacially slow by our "observe it happening" (as meant by the website) timescale.

This is one of many dishonest tactics employed by Creationists to cast doubt upon evolution: they propose things that sound reasonable to laypersons but which are simply not how it really works, and then try to fault evolutionary biologists for not producing proof of something they have never claimed happens (or can happen) in the first place.

"Theology made no provision for evolution. The biblical authors had missed the most important revelation of all! Could it be that they were not really privy to the thoughts of God?" - E. O. Wilson
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04-11-2016, 03:07 PM (This post was last modified: 04-11-2016 03:12 PM by RocketSurgeon76.)
RE: The Atheist Delusion (new Christian movie)
When talking about new species "appearing in the record", it might help you if you imagine fossils as a single image from a movie that's running. Out of ten thousand slides that make up the movie, you pick up slides #4321 and #8272... you can see that the protagonist has grown old in between those two slides, but don't have all the intervening slides to show when he aged. We could express this as "the old man appears sometime around the middle of the film", but that doesn't mean that one day the old man woke up and was old.

"Theology made no provision for evolution. The biblical authors had missed the most important revelation of all! Could it be that they were not really privy to the thoughts of God?" - E. O. Wilson
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04-11-2016, 10:03 PM
RE: The Atheist Delusion (new Christian movie)







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16-11-2016, 01:06 PM
RE: The Atheist Delusion (new Christian movie)
(04-11-2016 11:01 AM)Chas Wrote:  
Quote:Also most speciation happenned after cambrian explosion so average rate should be much higher.
Citation required.
I couldn't find exact numbers but here's a nice chart [Image: 271D39425448DD7A2F8F7C]
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16-11-2016, 01:41 PM
RE: The Atheist Delusion (new Christian movie)
(16-11-2016 01:06 PM)dimaniac Wrote:  
(04-11-2016 11:01 AM)Chas Wrote:  Citation required.
I couldn't find exact numbers but here's a nice chart [Image: 271D39425448DD7A2F8F7C]

It isn't true that the Cambrian was a period of higher speciation than any other time:
from this publication by Richard K. Bambach, Andrew H. Knoll, Steve C. Wang published in Paleobiology (http://www.bioone.org/doi/full/10.1666/0...0.CO%3B2): "As a side issue, but one related to proportional diversity change and its timing, it is interesting to note that the only times when proportional increase of diversity exceeds 13.5% are during the Cambrian Explosion, the Ordovician Radiation (just ending in the early Caradocian at the start of Fig. 2), in the immediate aftermath of each of the five “mass depletions” of diversity, and briefly (single intervals only) in the Late Cretaceous (Turonian) and Neogene (early Miocene) (Fig. 2)."

Their figure 2:    

Their figure 6:    
The apparently high origination rate at the very beginning of the Cambrian is a boundary condition most likely. It represents the appearance of hard-bodied taxa in the fossil record, it does not meant that the speciation rate was higher.

As Bambach et al. note, there are multiple periods where the rate of origination balanced by the rate of extinction are elevated throughout the Phanerozoic. This is why when you look at graphs (like the one below from Sepkoski) showing the total diversity of life throughout the Phanerozoic, they show a gradual increase forward in time with different intervals showing increases in total biodiversity (such as the Cambrian Explosion, the Ordovician Radiation, the Mesozoic and Cenozoic Marine Revolutions). The Paleozoic plateau is also interesting, probably because the Paleozoic fauna had more or less reached peak diversity.
   

It also depends on how you sample and analyze the fossil data too. Below is the same Sepkoski curve on the left, and Alroy's on the right. In either case, what it would mean for the Cambrian to have higher speciation rates than the rest of the Phanerozoic would be a very steep slope in diversity during the Cambrian.
   

The phylogenetic tree you've linked to doesn't substantiate your assertion that the Cambrian had higher rates of origination. What it shows is that crown groups all have ancestors that first appear in the fossil record by the early Cambrian.

But there is no reason to believe that origination rates in a blanket sense were higher in the Cambrian than any other period in Earth's history. What is true is that taxa with hard parts diversified "quickly" during the Cambrian, resulting in an apparent "explosion" in life. The reality is that this diversification occurred over tens of millions of years. It is also true that the Cambrian fauna was quite unique from the rest of the Paleozoic (the reason why the Sepkoski curves break it up into Cm for Cambrian fauna, Pz for Paleozoic, and Md for modern). The Cambrian fauna diversified early in the Cambrian, but not at rates that are abnormal when looking at the rest of the Phanerozoic. It somewhat appears that way only because it was a diversification of hard-bodied organisms, so there was an apparent sudden appearance of fossils but that is a preservational signal.

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16-11-2016, 01:47 PM
RE: The Atheist Delusion (new Christian movie)
ITT: diamanic learns a new word: speciation. That's something, anyway. I really don't know how anybody gets past the intro of "produced by Ray Comfort," as objected to in the first reply. Guy's a total fucking lizard.

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16-11-2016, 02:39 PM
RE: The Atheist Delusion (new Christian movie)
(04-11-2016 10:57 AM)dimaniac Wrote:  
(04-11-2016 10:44 AM)Commonsensei Wrote:  Am I do that math right?
The way i did it:
https://en.wikipedia.org/wiki/Biodiversity
Quote:More than 99 percent of all species, amounting to over five billion species,[12] that ever lived on Earth are estimated to be extinct.
https://en.wikipedia.org/wiki/Abiogenesis
Quote: life arising from non-living matter, such as simple organic compounds. It is thought to have occurred on Earth between 3.8 and 4.1 billion years ago
5 billion species/4 billion years = 1 specie/year.
Also most speciation happenned after cambrian explosion so average rate should be much higher.

Even if Ray Comfort has a valid point, this wouldn't disprove evolution.

Even if evolution is a "fairy tale for adults" it doesn't mean your; or Ray Comfort's fairy tale, is the correct one. Drinking Beverage

Guess what you would need to establish the scientific validity of another theory to replace evolution?

Something Christian creationist fairy tales never have- evidence.

Gods derive their power from post-hoc rationalizations. -The Inquisition

Using the supernatural to explain events in your life is a failure of the intellect to comprehend the world around you. -The Inquisition
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22-11-2016, 09:21 AM
RE: The Atheist Delusion (new Christian movie)
(16-11-2016 01:06 PM)dimaniac Wrote:  
(04-11-2016 11:01 AM)Chas Wrote:  Citation required.
I couldn't find exact numbers but here's a nice chart [Image: 271D39425448DD7A2F8F7C]

No rebuttal? Consider

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