Refusal to Accept anything that might be directed

[Arete]

This too might be nitpicking but no one knows what this common ancestor was, what it looked like, and by that fact even if you did find a fossil you still would not know if it was our common ancestor.

 

Brainteaserfan suggested (whether intentionally or unintentionally - just to be certain there's no implications) that evolutionary theory had humans evolving from chimps, which is does not.

 

We actually have physical evidence of several common ancestors of extant hominids.

http://www.talkorigins.org/faqs/homs/species.html

http://www.science20.com/news_articles/meet_ardipithecus_ramidus_early_hominid_common_ancestor_was_neither_chimp_nor_human_says_study

 

Evolution is a continuum. Expecting a magic discovery of a specific, pinpointed "common ancestor" is to completely misinterpret evolutionary theory regarding speciation - it's a piece of supposed "evidence" that is not expected under theoretically supported prediction.

See coalescent theory, species trees and divergent selection.

http://en.wikipedia.org/wiki/Coalescent_theory

http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1000501

en.wikipedia.org/wiki/Divergent_evolution

[Brainteaserfan]

Brainteaserfan suggested (whether intentionally or unintentionally - just to be certain there's no implications) that evolutionary theory had humans evolving from chimps, which is does not.

 

We actually have physical evidence of several common ancestors of extant hominids.

http://www.talkorigi...ms/species.html

http://www.science20...uman_says_study

 

Evolution is a continuum. Expecting a magic discovery of a specific, pinpointed "common ancestor" is to completely misinterpret evolutionary theory regarding speciation - it's a piece of supposed "evidence" that is not expected under theoretically supported prediction.

See coalescent theory, species trees and divergent selection.

http://en.wikipedia....alescent_theory

http://www.ploscompb...al.pcbi.1000501

en.wikipedia.org/wiki/Divergent_evolution

Arete, I just wanted to let you know that I did find your post fascinating on the other page (hence the +1). I didn't think I had enough to say (that was well backed up) to warrant responding, that's all.

 

So what if that's not what your bible meant? What does the science of evolution have to do with that?

And you still don't get it, because we didn't come from a far different species, we only came from a slightly different species, who then came from a species slightly different to it, and that species came from a species slightly different to that, and etc.

But we would still end up a totally different species, and I believe that God had some level of adaption "built in."

 

 

 

In fact, there's already ways in which different parts of the human race has evolved even within 6,000 years. Have you ever heard of the Black Plague? Well only the Europeans who happened to have mutations containing strong immune systems survived it, and they passed that on.

Yes, but again, I believe that resistance already existed. In the same way, bacteria don't really evolve resistance to antibiotics, I believe that they gain it from other members of the same species. Or maybe I have a really scientifically screwed up view?

Edited November 3, 2011 by Brainteaserfan

[kitkat]

Brainteaserfan suggested (whether intentionally or unintentionally - just to be certain there's no implications) that evolutionary theory had humans evolving from chimps, which is does not.

 

We actually have physical evidence of several common ancestors of extant hominids.

http://www.talkorigins.org/faqs/homs/species.html

http://www.science20.com/news_articles/meet_ardipithecus_ramidus_early_hominid_common_ancestor_was_neither_chimp_nor_human_says_study

 

Evolution is a continuum. Expecting a magic discovery of a specific, pinpointed "common ancestor" is to completely misinterpret evolutionary theory regarding speciation - it's a piece of supposed "evidence" that is not expected under theoretically supported prediction.

See coalescent theory, species trees and divergent selection.

http://en.wikipedia.org/wiki/Coalescent_theory

http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1000501

en.wikipedia.org/wiki/Divergent_evolution

 

 

Your comment of expecting a magic discovery of a specific pinpointed "common ancestor" is to completely misinterpret evolutionary theory falls short when you look up the genome articles where you can plug in any (2) diff animals and it will provide you with the date they split from each other, the date meaning common ancestry. Dates don't seem to be a problem for genetic comparison but it is for actual fossil evidence to pinpoint ancestor. Come on this is hard to swallow with any doubt.

 

Please understand I don't have a problem with evolution theory, I do have a problem with agreeing with your evidence and how it is interpreted.

[questionposter]

But we would still end up a totally different species, and I believe that God had some level of adaption "built in."

 

Nope, we don't end up a totally different species because we didn't come from chimps, we came from something very very similar to us, like neandtherthals who had like 100 different ancestors the last of which being most similar to chimps. Your still not getting just how gradual evolution really is. We never came from anything drastically different that us, only very slightly, there's no possible way a chimp could give birth to a human.

 

 

 

Yes, but again, I believe that resistance already existed. In the same way, bacteria don't really evolve resistance to antibiotics, I believe that they gain it from other members of the same species. Or maybe I have a really scientifically screwed up view?

 

Yeah, bacteria gain resistance form other members who randomly had the mutation to survive and passed it on. Whether or not god wanted that to happen is something I can't answer.

Edited November 3, 2011 by questionposter

[Arete]

Your comment of expecting a magic discovery of a specific pinpointed "common ancestor" is to completely misinterpret evolutionary theory falls short when you look up the genome articles where you can plug in any (2) diff animals and it will provide you with the date they split from each other, the date meaning common ancestry.  Dates don't seem to be a problem for genetic comparison but it is for actual fossil evidence to pinpoint ancestor.  Come on this is hard to swallow with any doubt.

Please understand I don't have a problem with evolution theory, I do have a problem with agreeing with your evidence and how it is interpreted.

 

As a postdoc working in a phylogenetics lab, occasional lecturer and author of above-mentioned phylogenetic papers, I at least like to think that my basic knowledge of phylogenetic tree reconstruction methodology (I say methodology because at least, Bayesian tree reconstruction is founded on coalescent theory which I linked to in my last post) is reasonable.

 

1) We generally don't use entire genomes, as it is an assumption of most methods that loci are unlinked and accumulate mutations under a neutral model of selection.

2) Time calibrations for phylogenetic divergence estimation are generally based on fossils.

 

What you do is identify a fossil/multiple fossils which undoubtedly represents a common ancestor of some or all of the terminal taxa you are interested in. The estimated date of that fossil's formation represents a hard lower bound for the relevant node in the phylogeny (i.e. we know that the group of organisms in question is at least this old). By applying a lognormal prior distribution to that node, and a relaxed clock model to mutation rates across the tree, we can generate probabilistic ranges of divergence around each node in the tree - giving us an idea of the dates certain species split from each other.

 

Calibrated phylogenetic reconstruction is based on fossils, so the conundrum you seem to be posing cannot, by definition, exist - if the fossil evidence a tree is calibrated on is wrong so are the estimates of divergence.

 

If you're interested in how it works, grab some free nucleotide sequence data from Genbank, use free web based clustal to align it and have a play with the Beast software (it's free and probably to most user friendly as it has a GUI)

http://www.ncbi.nlm.nih.gov/genbank/

http://www.ebi.ac.uk.../msa/clustalw2/

http://beast.bio.ed.ac.uk/Main_Page

Edited November 3, 2011 by Arete

[Phi for All]

I believe that God created me -- I certainly don't think we evolved from chimps.

This is the one that really makes me sad. It's creationist 101, and it's been handed down since the Scope's trial. It really shows that the speaker has no interest in understanding how evolution works, and is content to repeat the ignorant catch phrases of others. No offense meant to you personally, Brainteaserfan. This is a strawman argument I've heard my whole life, it's inaccurate, it's dishonest and it pains me to see it still is used on the youth in this country.

[kitkat]

This is the one that really makes me sad. It's creationist 101, and it's been handed down since the Scope's trial. It really shows that the speaker has no interest in understanding how evolution works, and is content to repeat the ignorant catch phrases of others. No offense meant to you personally, Brainteaserfan. This is a strawman argument I've heard my whole life, it's inaccurate, it's dishonest and it pains me to see it still is used on the youth in this country.

 

I agree with you and religious beliefs are brainwashed into children's evolving belief system very early in life and that is why it is so hard to convince them of reality.

[Brainteaserfan]

This is the one that really makes me sad. It's creationist 101, and it's been handed down since the Scope's trial. It really shows that the speaker has no interest in understanding how evolution works, and is content to repeat the ignorant catch phrases of others. No offense meant to you personally, Brainteaserfan. This is a strawman argument I've heard my whole life, it's inaccurate, it's dishonest and it pains me to see it still is used on the youth in this country.

Phi, I do have a huge interest in learning about evolution, and learning about the evidence for it. How does the statement reflect no interest? I believe (for now) there is more evidence for a God and creationism.

 

I agree with you and religious beliefs are brainwashed into children's evolving belief system very early in life and that is why it is so hard to convince them of reality.

I am NOT brainwashed. My parents wouldn't require me to learn about evolution from secular books if they were trying to brainwash me.

[kitkat]

Phi, I do have a huge interest in learning about evolution, and learning about the evidence for it. How does the statement reflect no interest? I believe (for now) there is more evidence for a God and creationism.

 

 

I am NOT brainwashed. My parents wouldn't require me to learn about evolution from secular books if they were trying to brainwash me.

 

 

Were you being taught about evolution at the same time you learned about your religious views?

[questionposter]

Phi, I do have a huge interest in learning about evolution, and learning about the evidence for it. How does the statement reflect no interest? I believe (for now) there is more evidence for a God and creationism.

 

 

 

Well, evolution is pretty sound, I'm pretty sure I even saw it in my backyard, so how about that what God said wasn't properly interpreted? I mean it was also interpreted from creationism that mice were born from or created out of hay stacks, and boy was that wrong.

Edited November 3, 2011 by questionposter

[Brainteaserfan]

Well, evolution is pretty sound, I'm pretty sure I even saw it in my backyard, so how about that what God said wasn't properly interpreted? I mean it was also interpreted from creationism that mice were born from or created out of hay stacks, and boy was that wrong.

Ottomh, the same guy who came up with spontaneous generation donated many highly valued ideas to science.

 

Besides, that's the fallacy of saying that because something bad came from an idea, the idea is bad.

Edited November 3, 2011 by Brainteaserfan

[questionposter]

Ottomh, the same guy who came up with spontaneous generation donated many highly valued ideas to science.

 

Besides, that's the fallacy of saying that because something bad came from an idea, the idea is bad.

 

But the mouse coming from a haystack is the idea itself, and it's not good or bad, its just wrong. The idea of creationism at least in the way its currently interpreted has been proven to not be right in some cases, and in other cases it just can't be determinate if it's right or wrong.

 

Not only that, but I don't know who is "Ottomh" guy is, and changing the way you look at things and accepting new ideas that explain things better than old ideas is part of science anyway.

Edited November 3, 2011 by questionposter

[Ophiolite]

As a postdoc etc......

A very useful and interesting post. Thank you.

[Brainteaserfan]

But the mouse coming from a haystack is the idea itself, and it's not good or bad, its just wrong. The idea of creationism at least in the way its currently interpreted has been proven to not be right in some cases, and in other cases it just can't be determinate if it's right or wrong.

 

Not only that, but I don't know who is "Ottomh" guy is, and changing the way you look at things and accepting new ideas that explain things better than old ideas is part of science anyway.

Ottomh=off the top of my head.

Aristotle.

 

I'll put together a real reply when I get a chance.

Edited November 4, 2011 by Brainteaserfan

[Cap'n Refsmmat]

Phi, I do have a huge interest in learning about evolution, and learning about the evidence for it. How does the statement reflect no interest? I believe (for now) there is more evidence for a God and creationism.

It reflects no interest because no theory of evolution says humans evolved directly from chimps.

 

You might try perusing TalkOrigins:

 

http://talkorigins.org/faqs/faq-intro-to-biology.html

http://talkorigins.org/faqs/comdesc/

[jeskill]

What you do is identify a fossil/multiple fossils which undoubtedly represents a common ancestor of some or all of the terminal taxa you are interested in. The estimated date of that fossil's formation represents a hard lower bound for the relevant node in the phylogeny (i.e. we know that the group of organisms in question is at least this old). By applying a lognormal prior distribution to that node, and a relaxed clock model to mutation rates across the tree, we can generate probabilistic ranges of divergence around each node in the tree - giving us an idea of the dates certain species split from each other.

 

 

I think it makes intuitive sense why you'd use a lognormal prior, but my sleep-deprived brain can't quite figure out why. Why do you use a lognormal prior? A n00b to Bayesian statistics wants to know.

[questionposter]

Ottomh=off the top of my head.

Aristotle.

 

 

My bad, I thought you were using it to refer to a person, as in "person x, the person who said these things had this to say about science..."

Edited November 4, 2011 by questionposter

[Arete]

I think it makes intuitive sense why you'd use a lognormal prior, but my sleep-deprived brain can't quite figure out why. Why do you use a lognormal prior? A n00b to Bayesian statistics wants to know.

 

It's not so much a facet of Bayesian stats as evolutionary theory. A common ancestor fossil represents a hard "at least" date - the presence of a common ancestor demarks a point at which you can infer that the split had to occur after. Due to the fact speciation is an ongoing process, happens over a considerable time and it's conceptually hard to call exactly when it has occurred by, the absolute minimum date of a speciation event is much more squishy.

 

A lognormal distribution is a good way to reflect the hard maximum, squishy minimum nature of fossil calibrations

 

If you're using a vicariant event e.g. closing of the isthmus of Panama (I generally don't like them because of the huuuuge confidence intervals they require to be in any way realistic) A uniform or normal distribution around the prior might be more suitable.

Edited November 4, 2011 by Arete

[FrankQuietly]

The original post from kitkat is a thought provoking one, and I mean from a scientific perspective. Most of the replies have disagreed with kitkats intuition by describing the ability to evolve adaptability. What has been called the evolution of evolvability. So organisms over time evolve systems and processes that improve their ability to evolve to unknown future environmental changes.

 

Kitkat, if I understand your intuition to be that organisms appear to have a built-in ability to evolve in a certain direction, as if toward something. Or they appear to have some mechanisms that help them to adapt and evolve over time, then your intuition is actually a scientifically valid hypothesis, it is testable, and it makes predictions.

 

Prediction such as the directional changes that have been witnessed in evolution so far should continue in the same direction. For example, take the observation that the chemical complexity of organisms has increased over time, we could predict that it would continue to do so.

 

And as a supporting analogy, consider when a fertilised egg develops into a frog, it proceeds along a directed pathway from tadpole to the frog. This is mostly pre-determined by the fertilised egg's genetics with some environmental influence along the way. Now imagine that the universe itself proceeds along a directed pathway, i.e. the laws of the universe / physics are such that certain evolutionary pathways are to be expected. Then your intuition would be correct and there is a directing force to evolution that is outside the basic evolution system and any evolved evolvability.

 

So I genuinely believe Kitkat that your intuition is actually a scientific hypothesis and a very interesting and thought provoking one to investigate.

 

The trouble I fear you will have in developing arguments to support your hypothesis is that most of the evidence will be the same evidence that supports the currently accepted theories of evolvability etc. So you would really have to think outside the box to begin finding certain processes that seem to direct evolution but do not appear to be derived from evolution itself.

 

Frank

[CharonY]

For example, take the observation that the chemical complexity of organisms has increased over time, we could predict that it would continue to do so.

What is this assertion based on? Most chemical reactions that more complex organisms are capable of, can also found in larger variety in the prokaryotic realm for instance. And even if that was true it is easy to extrapolate or construct trends from complex data. However, it doe not mean that a trend really exists.

[FrankQuietly]

Hi CharonY,

 

Yes that assertion is not very precise or well worded. In fact the term chemical complexity is poorly chosen. But the intention behind it is that the evolution of compartmentalised cells, multicellularity and integrated ecosystems is an increase in complexity. Perhaps not chemical complexity, but complexity nonetheless.

 

What do you think?

[CharonY]

Here is the thing, once a certain level of complexity has reached, it allows for certain other features that are not successful otherwise (e.g. by gaining access to new niches). However, it does not mean that it will continue. If there was a continuous trend, all "simpler" lifeforms would eventually be replaced, which is certainly not the case. Furthermore, basing complexity on one certain feature (e.g. anatomy) is, in a way, cherry-picking. If I focus e.g. on metabolic abilities instead, a handful of bacteria would be far more complex than e.g. all animals taken together. Also the scaling is skewed, anatomical complexity is not directly represented on the genetical level. This is evidenced by the relatively moderate increase of genes from bacteria (~4k genes) to humans (~20k). Of course one could argue that regulation could be more complex, but then it depends on what element one focusses on. Developmental regulation is of course far more complex in multicellular organism. But then metabolic adaptations and stress responses are far more limited.

[FrankQuietly]

I appreciate that cherry picking and comparing certain aspects may be poor argument.

 

Do you think the evolutionary history on earth shows an increase in complexity?

 

What is your take on the complexity trend of biosphere in its totality?

 

And what about the idea that identifying a trend and predicting its future direction to continue is a potential argument for an in built tendency of the biosphere to increase in complexity, something not derived from evolution but a driving force of it?

[CharonY]

I tend not to think in terms of complexity as (I think) it is quite a loaded term. As mentioned in other discussion, biology has many imprecise, but useful definitions (such as species, for instance). I just do not feel that "complexity" is a useful term in this context. All organism that we observe today were subjected to evolutionary mechanisms for the same amount of time, as such assigning different level of complexity as a whole is not terribly helpful. If one focuses on only one element then one can clearly distinguish between levels of complexity, but it is not really a reflection of evolutionary reality. For instance, dinosaurs, as a whole, are not more or less complex than existing birds or reptiles. However, if only looking at the ability to fly, birds have improved quite a bit.

Also the biosphere is not striving towards increasing complexity. Evolution allows more and more niches to be filled, but as a side process of biological activity certain other niches may be destroyed.

 

One has to go back way, way, way back in time to find a situation where biodiversity was low and many niches unused. But at a certain level you will find changes rather than definite trends. Also, it is dangerous to argue from a post hoc position and draw a line towards where we are today, as with different random event outcome may change quite a bit (i.e. trends built from that perspective are not necessarily true, even if you could observe them).

[FrankQuietly]

I am tending to agree with you that complexity is not a good avenue to argue for direction in evolution as initially asked here.

 

Although I think it is blatantly obvious that complexity has increased over time, i.e. from no life to life, from simple ecosystems to complex ecosystems. And you could argue that once evolving systems begin they will tend to these more integrated ecosystems, but this is not a directed evolution as intended by the original poster.

 

The original post was a question about the teleological direction in evolution, as if it had an end it worked toward. So complexity is not something it would strive to be, but it may be an inevitable outcome.

 

I think the analogy of a pre determined plan, although a very religious concept that tends toward Paleys watchmaker and the argument from design, is still a valid scientific hypothesis.

 

I have never seen anything that even hints at accepting it as true, and many good arguments against it. But nonetheless it is conceivable that future science could uncover an inevitability to the evolution process that is present from the laws of nature and physics etc. Many would no doubt want human cognition to be at the pinnacle but I wouldnt want to give any special mention to us humans just yet. If it turns out us humans can develop a method of creating universes then I may pay more attention as this would suggest that an evolutionary / developmental model for our own universe is more valid.

 

Some people have explored this from a thermodynamic perspective developing theories based on the maximisation of energy dissipation as a direction to evolving systems. Seems a bit lame to me and just riding on the back of the universality of thermodynamic laws.

 

frank

Edited February 15, 2012 by FrankQuietly