Evolution?

[Job 33:6]

And the above post doesnt mean that many proto zebras didnt die as a result of bad joints and poor mutations. It just means that the ones alive today have benefited, else they would be dead as others have become.

But peoples poor decisions and selfishness is really a whole other topic. Us hunting them for sport doesnt directly hurt our own personal fitness, and so you might see species going extinct as a product of our success, but this should not be conflated with the idea that bad joints are what is leading species to extinction. Bad joints would be a product of detrimental mutations. Predation is a product of our beneficial mutations and success. Which just so happens to also be tied in with our selfishness and lack of care for others that arent as fit as we are.

 

[stevevw]

Earth really has what is in a practical sense, an infinite amount of resources. We simply have made poor decisions in managing those resources as a result of our own imperfections.

Renewable energy for example, is available to us. Solar energy in a practical sense, is infinite. Its use would theoretically eliminate things like running out of coal produced electricity and oil produced gasoline.

We simply have to make that decision. But because many of us, the wealthy of us, aren't directly under threat (i can just hangout on my couch and watch tv comfortably), we dont strive to change, so we accept the loss of others lives, while as societies we benefit. Unfortunately.

But ultimately, the loss of say...starving children in africa, does not equate to the idea that our increased intellect and use of fuel oil and agriculture, is detrimental to our fitness. We, the wealthy, are living longer than ever, and are healthy and fit enough to enjoy said long life. We do not actually lose anything as a result of our personal mutations, in the grand scheme of things. Other societies may, but we are in power and we do not, therefore, our fitness is not threatened.

As far as evolution is concerned it is humans ability to play God and mess with nature that is causing the problem. Our ability to defy death and prolong life through technology and medicines may end up having the opposite effect of causing us to become extinct. It is our tampering with the genetic code of life and change the natural setup that may introduce changes that have far worse consequences than we realize in the end. That is why I say that life was already functioning good and there is evidence that this is the case from the beginning or at least from a very early stage in the history of life and now things are being change and are degrading one way or another.

 

[Job 33:6]

As far as evolution is concerned it is humans ability to play God and mess with nature that is causing the problem. Our ability to defy death and prolong life through technology and medicines may end up having the opposite effect of causing us to become extinct. It is our tampering with the genetic code of life and change the natural setup that may introduce changes that have far worse consequences than we realize in the end. That is why I say that life was already functioning good and there is evidence that this is the case from the beginning or at least from a very early stage in the history of life and now things are being change and are degrading one way or another.

I agree that we could end up killing ourselves, say with nuclear warfare or something along those lines. But i dont think this means that...all mutations are detrimental to us.

Its easier to not look at humanity as an example, as our intelligence is really artificially changing natural selection and even as you have pointed out, our genetics through things like genetic manipulation.

To remove the shroud of artificial manipulation, really we should just look at the animal kingdom beyond mankind to understand how mutations are operating in the lives of living things, without intellectual manipulation.

 

[stevevw]

also, youre jumping between ideas. One idea being that fish had the dna for legs (or whatever youre getting at) and the other idea being that the increased fitness as a result of mutations might actually come at a cost of life (greater than the benefit to life), which is contradictory. If it were the case that bad joints decreased fitness, moreso than the zebras speed and agility increased fitness, then the zebra wouldnt exist because it would die as a result of bad joints.

Why is it contradictory. All life having similar development programs that produce similar features more or less can have those programs switched on or off. That means there can be a loss or gain of features. But it also does not mean that there are mutations that can degrade genetic info as well.

 

[stevevw]

I agree that we could end up killing ourselves, say with nuclear warfare or something along those lines. But i dont think this means that...all mutations are detrimental to us.

Its easier to not look at humanity as an example, as our intelligence is really artificially changing natural selection and even as you have pointed out, our genetics through things like genetic manipulation.

To remove the shroud of artificial manipulation, really we should just look at the animal kingdom beyond mankind to understand how mutations are operating in the lives of living things, without intellectual manipulation.

But for me, I think that the human example shows that there are many ways that evolution can be undermined and shown to not be a good way to measure how life developed and changes. How do we know that there is a similar way in which animals do that to each other and have done all along? It seems in one way or another natural selection can be sidetracked, overpowered and directed by other forces and therefore too much emphasis has been given to Neo-Darwinism as the only mechanism driving all life to change. I have mentioned some of the other processes that undermine and direct natural selection or produce variations besides random mutations such as in the EES or through other non-adaptive forces.

 

[Job 33:6]

"
But then those qualities are only good for that situation and may not be good over all. The Zebras that run faster and jump high may be developing weak joints from them subjecting those joints to constant pounding.


"

You asked why this is contradictory. Well, it sounds like youre suggesting that the zebras mutation which resulted in the increasing in speed and agility, actually decreased their fitness overall. Which is a direct contradiction.

Like I said before, if it were true that weak joints outweighted the benefits of increased speed and agility, the zebras would not be alive today because theyd all have died due to bad joints.

 

[Job 33:6]

But for me, I think that the human example shows that there are many ways that evolution can be undermined and shown to not be a good way to measure how life developed and changes. How do we know that there is a similar way in which animals do that to each other and have done all along? It seems in one way or another natural selection can be sidetracked, overpowered and directed by other forces and therefore too much emphasis has been given to Neo-Darwinism as the only mechanism driving all life to change. I have mentioned some of the other processes that undermine and direct natural selection or produce variations besides random mutations such as in the EES or through other non-adaptive forces.

I wouldnt say that natural selection has been overpowered. It is just less apparent and has taken on different forms because mankind has become so prosperous.

We no longer have to deal (in most cases) with being eaten by predators. We rely on more of an intellectual fitness than a physical fitness these days.

But realistically, for the past 600 million years, fitness hasnt been with relation to intelligence. Fish arent going to catch a plane to the other side of the planet to interbreed with other fish either, so you had more isolated populations.

So your interests seem to be more in relation to the evolution of mankind in particular, as opposed to with life as it otherwise commonly exists or has existed in the past.

And, i dont see anything wrong with arguing that many factors weight into the evolution of mankind during this age of industrialization. But id say this is really another topic and shouldnt be confused with questions of whether or not mutations can be beneficial to a species fitness.

 

[sfs]

What about the 99% of other species in the past that have gone extinct through the accumulation of mutations.

Where did you get the idea that 99% of species have gone extinct because of accumulated mutations? It's an idea that has no connection to actual evolutionary biology. If it were to consistently happen to species, then all life would be extinct, since all existing species descend from those earlier extinct species.

How can we tell whether there are no current species going down the same path?

Look, you were the one who posted studies about the maximum tolerable rate of mutation, a rate that is much, much higher than the actual rate. So you've already answered your own question.

Don’t we lose 1,000’s of species every year

Quite possibly.

and some of these are because of harmful mutations?

That's something you made up.

When you say the measured mutation rate is tolerable, isn’t this really saying that mutations have to be tolerated and therefore mutations are slightly harmful.

I'm saying what I said: the actual mutation rate is such that we should have no problem maintaining our current fitness.

As Michael Lynch in his paper states that all complex life suffers from higher deleterious mutations and extinction rates because they experience reduced recombination rates which diminish the power of natural selection.

Which is a different argument than the one you're making. He's saying it's harder for complex organisms to adapt via positive selection.

Considering that most vertebrates have smaller populations, often separate into smaller populations to develop new species and had to have begun as smaller populations throughout the history of evolution it seems inevitable that many species have experienced the harmful effects of mutations and continue to do so.

Seems inevitable to whom? You have presented zero evidence to support this claim.

As stated in the paper I posted earlier scientists are discovering harmful mutations that have been hidden in the genome.

Yes, you did post that earlier. And I pointed out that the paper was talking about somatic mutations, which by definition have nothing whatever to do with mutations that accumulate across generations. So why are you bringing it up again?

Then why do humans, for example, have so many diseases and disorders caused by mutations.

Because deleterious mutations do occur, and are weeded out by natural selection. The diseases and disorder you're talking about are natural selection in operation.

As stated in the video I linked in the previous post some mutations are non-random and target specific sites in the DNA to make changes that allow creatures to adapt to their environments.

That may be what the video says, but if so the video is wrong.

Actually it is the fast-increasing population that is causing the increase in mutations and with this the increase in harmful mutations. The accumulation of mutations is more to do with the high rate of mutations in human and the speed in which they happen. This along with the lifestyle of modern humans and the improvements in technology to allow people to live longer is making it hard for natural selection to weed out these harmful mutations. Hence, we are seeing over 250 new genetic disorders happening every year and increasing.

Again, this has no connection to actual human genetics -- a subject I spent quite a few years studying and publishing in. Look, I don't have time to tell you over and over again why what you're arguing is wrong, especially since you don't seem to care and just post the same links again. This stuff is what I do for a living. The claims you're making are simply not supported by the papers you're citing.

 

[stevevw]

"
But then those qualities are only good for that situation and may not be good over all. The Zebras that run faster and jump high may be developing weak joints from them subjecting those joints to constant pounding.

You asked why this is contradictory. Well, it sounds like youre suggesting that the zebras mutation which resulted in the increasing in speed and agility, actually decreased their fitness overall. Which is a direct contradiction.

Like I said before, if it were true that weak joints outweighted the benefits of increased speed and agility, the zebras would not be alive today because they all have died due to bad joints.

I am merely pointing out how basing the evolution of features, traits and behaviours in living things only on adaptive evolution is silly as it cannot account for all the different situations that creatures are subject to and the evidence does not support this. You have assumed that the ability for the Zebra to run fast is the result of random mutations in the first place so there is no contradiction on my part as I am not looking at things that way.

I am just saying there are many different circumstances that can affect creatures and there are other ways they can change besides adaptive evolution. If you only see things in adaptive terms then there are always going to be contradictions becuase this does not fit the evidence. The ability of a Zebra to run fast was not the result of random mutations but rather was something the Zebra could already do.

The vast majority of biologists engaged in evolutionary studies interpret virtually every aspect of biodiversity in adaptive terms. This narrow view of evolution has become untenable in light of recent observations from genomic sequencing and population-genetic theory.
The frailty of adaptive hypotheses for the origins of organismal complexity

Charles Darwin conceived of evolution by natural selection without knowing that genes exist. Now mainstream evolutionary theory has come to focus almost exclusively on genetic inheritance and processes that change gene frequencies. Yet new data pouring out of adjacent fields are starting to undermine this narrow stance. An alternative vision of evolution is beginning to crystallize, in which the processes by which organisms grow and develop are recognized as causes of evolution.
Does evolutionary theory need a rethink?

 

[Job 33:6]

I am merely pointing out how basing the evolution of features, traits and behaviours in living things only on adaptive evolution is silly as it cannot account for all the different situations that creatures are subject to and the evidence does not support this. You have assumed that the ability for the Zebra to run fast is the result of random mutations in the first place so there is no contradiction on my part as I am not looking at things that way.

I am just saying there are many different circumstances that can affect creatures and there are other ways they can change besides adaptive evolution. If you only see things in adaptive terms then there are always going to be contradictions becuase this does not fit the evidence. The ability of a Zebra to run fast was not the result of random mutations but rather was something the Zebra could already do.

The vast majority of biologists engaged in evolutionary studies interpret virtually every aspect of biodiversity in adaptive terms. This narrow view of evolution has become untenable in light of recent observations from genomic sequencing and population-genetic theory.
The frailty of adaptive hypotheses for the origins of organismal complexity

Charles Darwin conceived of evolution by natural selection without knowing that genes exist. Now mainstream evolutionary theory has come to focus almost exclusively on genetic inheritance and processes that change gene frequencies. Yet new data pouring out of adjacent fields are starting to undermine this narrow stance. An alternative vision of evolution is beginning to crystallize, in which the processes by which organisms grow and develop are recognized as causes of evolution.
Does evolutionary theory need a rethink?

Seems like you're making stuff up to me.

If the zebra could already run fast and jump high, then so could the fish further back in it's lineage.

A lot of what you're saying sounds speculative and contradictory as well.

For example, you suggested that poor joints might our weight the fitness benefits of increased speed and agility. But obviously this isn't the case, else the zebra wouldn't be alive.

You mentioned countless species dying as a result of being overloaded with deleterious mutations, but when inquired about this, you switched over to a discussion about human influenced extinctions.

You never clarified on these points.

You also mentioned something about species being originally more fit than they are now, but never clarified on what said original species was.

If you can formulate a clear and coherent case, I'll listen, but thus far you have been vague and all over the place.

 

[stevevw]

I wouldn't say that natural selection has been overpowered. It is just less apparent and has taken on different forms because mankind has become so prosperous.

Actually it has been diminished when it comes to human evolution. Human mutation rate is happening too fast and many genetic disorders are being maintained because modern technology and medicine are allowing those with disorders to survive and remain in the population. According to evolution by natural selection, the weak and afflicted would be weeded out of the population but they are now being allowed to survive into the population and this is rendering natural selection unable to get rid of these mutations out of the population.

But this is only one way Natural selection can be diminished. Natural selection can be deminished in small populations in general and also diminished or even disabled through other forces that dictate what natural selection can and cannot do. For example, if variations are the result of developmental bias the features are specific and well suited so therefore it won’t need to be sifted and selected as it is already a benefit. That diminishes or even eliminates the role of natural selection. Development bias will produce some features more readily than others.

If most of what we see today are the result of developmental programs, then there are very little roles for random mutations and selection because all the features stemming from those development programs have already been determined as the best possible body plans for living things to use. Taking this view then random mutations are actually undermining the pre-existing genetic information that supports those body plans and natural selection is continually trying to maintain those pre-existing body plans by ridding them of any random mutational changes that try to sabotage them.

The point I am making is that many people attribute too much creative power to natural selection when there are other forces involved that also help creatures change and adapt. Neo-Darwinism takes an adaptive and gene-centric view of how living things can evolve and this does not explain many anomalies that do not fit this picture.

The Modern Synthesis will explain any anomalies away as being trivial or come up with additional idea like convergent evolution to explain similarities in distantly related creatures when this may be the result of developmental programs using existing genetic info or phenotypic changes that are not even the result of genes (developmental plasticity) which therefore won't fit the gradualist view of transitional evolution.

Because Neo-Darwinism takes the adaptive view it has to explain how creatures adapt to environments to get their features, ie (the fastest zebras survive by adapting to environmental situations) but it cannot account for when animals have similar features in different environments. Or how species have different features in similar environments (i.e. different trees and leaves in the same environment or the cichlid fish example below). Whereas processes like developmental bias and plasticity as covered in the EES explain all of this much better i.e.

Developmental bias may also contribute to the many examples of convergence across the tree of life. For example, cichlid fishes from Lakes Malawi and Tanganyika exhibit striking similarities in body shape, despite being more closely related to species from their own lake than to those from the other lake [17,33]. Such repeated parallel evolution is generally attributed to convergent selection. However, inherent features of development may have channelled morphology along specific pathways, thereby facilitating the evolution of parallel forms in the two lakes [17,33]. If so, then the diversity of organismal form is only partly a consequence of natural selection—the particular evolutionary trajectories taken also depend on features of development.
http://rspb.royalsocietypublishing.org/content/282/1813/20151019


The Standard Evolutionary Theory (SET) explains such parallels as convergent evolution: similar environmental conditions select for random genetic variation with equivalent results. This account requires extraordinary coincidence to explain the multiple parallel forms that evolved independently in each lake. A more succinct hypothesis is that developmental bias and natural selection work together4, 5. Rather than selection being free to traverse across any physical possibility, it is guided along specific routes opened up by the processes of development5, 6.
Does evolutionary theory need a rethink?

Also, Niche construction can allow living things to control their own destiny by changing their environments which therefore diminishes the role of natural selection because living things are doing the selecting and therefore deminishing the need for natural selection.

‘Niche construction’ refers to the process whereby the metabolism, activities and choices of organisms modify or stabilize environmental states, and thereby affect selection acting on themselves and other species [71–73].


The EES proposes that variation is more predictable and selection pressures less exogenous than hitherto thought.
http://rspb.royalsocietypublishing.org/content/282/1813/20151019

 

[stevevw]

Seems like you're making stuff up to me.

If the zebra could already run fast and jump high, then so could the fish further back in its lineage.

A lot of what you're saying sounds speculative and contradictory as well.

It is not made up or speculative as I have linked the scientific support for what I have posted. The only contradiction is how the ideas of the EES can contradict what the Modern Synthesis is saying when it claims all variation and change is the result of random mutation and natural selection. Variation and change can also stem from developmental bias, plasticity, niche construction and extra genetic inheritance. Also, rather than the evolution of complex genetic networks being the result of adaptations, it is more associated with non-adaptive forces under a weak influence from natural selection.

There is no consistent tendency of evolution towards increased genomic complexity, and when complexity increases, this appears to be a non-adaptive consequence of evolution under weak purifying selection rather than an adaptation.
Darwinian evolution in the light of genomics

Any fish further back in the evolutionary lineage would also be evolved from pre-existing genetic info such as from developmental programs that could produce phenotypic variations by switching on or on those developmental programs.

For example, you suggested that poor joints might our weight the fitness benefits of increased speed and agility. But obviously this isn't the case, else the zebra wouldn't be alive.

I was merely pointing out how the adaptive view can be subject to many possible different situations that can produce many possible consequences so therefore can also be subject to a lot of speculation. That what may be attributed to adaptive reasons may also be the result of other processes such as those proposed by the EES including developmental processes, niche construction, plasticity and extra genetic inheritance. The ability of the zebra to run fast is not the result of adaptive evolution but because zebras already had the ability to run fast. Natural selection may explain the survival of the fittest, but it does not explain the arrival of the fittest.

You mentioned countless species dying as a result of being overloaded with deleterious mutations, but when inquired about this, you switched over to a discussion about human-influenced extinctions.

The human example is just one example of how mutations can affect populations. It is well acknowledged through the many scientific papers that small populations are susceptible to higher rates of harmful mutations. Logic tells us if most vertebrates had small populations when they were first evolving and branching off into new species then they must have also been subject to higher rates of harmful mutations.

You never clarified on these points.

You only have to join the dots as mentioned above by using logic.

You also mentioned something about species being originally more fit than they are now but never clarified on what said original species was.

I think you will find, I did. I said that complex creatures which are primarily vertebrates which must have had small populations in the past must have been more susceptible to higher rates of harmful mutations in the past if you believe the science on how small populations are affected by the accumulation of harmful mutations.

Apart from major extinction events how else could creatures have gone extinct? Like Neanderthals, for example, they dwindled in population which must have caused them to accumulate harmful mutations and eventually die out. But any new population being established will start out as small populations (which all vertebrates did as they diverged into new species) and therefore must be vulnerable as well.

If you can formulate a clear and coherent case, I'll listen, but thus far you have been vague and all over the place.

I think the above argument is pretty coherent and logical.

 

[Job 33:6]

Your ideas still aren't making sense to me.

"Any fish further back in the evolutionary lineage would also be evolved from pre-existing genetic info such as from developmental programs that could produce phenotypic variations by switching on or on those developmental programs. "

This is somewhat vague. If we keep going back, then you're interests in...developmental programs would end up going back into the precambrian days of evolution. Which seems irrelevant as it pertains to other forms of life that we have been discussing, such as zebras and people.

"Apart from major extinction events how else could creatures have gone extinct? Like Neanderthals, for example, they dwindled in population which must have caused them to accumulate harmful mutations and eventually die out."

The Neanderthal extinction was likely influenced by the presence of mankind. Much like many other extinctions in recent times. To some extent, they were probably out-competed. In which case again, it would reflect superior fitness and exceptional predation and influence by something more fit, moreso than the extinction would necessarily be driven by something like the accumulation of deleterious mutations. Some suggest that climate-change also weighted in to their outcome.

Neanderthal extinction - Wikipedia

Hypotheses on the fate of the Neanderthals include violence from encroaching anatomically modern humans,[3] parasites and pathogens, competitive replacement, competitive exclusion, extinction by interbreeding with early modern human populations,[4] and failure or inability to adapt to climate change. It is unlikely that any one of these hypotheses is sufficient on its own; rather, multiple factors probably contributed to the demise of an already widely-dispersed population.[5][6]

 

[Job 33:6]

" Logic tells us if most vertebrates had small populations when they were first evolving and branching off into new species then they must have also been subject to higher rates of harmful mutations."

To demonstrate this idea, you would need two papers. One to suggest a particular population size in which species would likely go extinct due to deleterious mutations, and you would need another paper discussing population sizes of early vertebrates. Neither of which have I seen posted in this discussion.

 

[stevevw]

Your ideas still aren't making sense to me.

"Any fish further back in the evolutionary lineage would also be evolved from pre-existing genetic info such as from developmental programs that could produce phenotypic variations by switching on or on those developmental programs. "

As we know the sudden appearance of most if not all phylum and basic body plans occurred in the Cambrian period. Did the instructions for these body plans come from nowhere or were there some sort of code that produces these. Despite the differences in form from the modern animals like Zebras to the Cambrian creatures, the Zebras basic body plan stems from the body plans that first appeared in the Cambrian period. So the developmental programs for these body plans must have been around from a very early time with the first creatures.

Perhaps it has been a case of the switching on and off of the particular genetic info for all body plan features to produce the different life forms ie limbs are similar despite whether they are fins of legs/arms so it is a case of a variation of the same basic body plan. As noted in embryology all life seems to develop along similar lines as though cast from the same mould and then will change in their fetus development according to that particular creature. This must have been in place from the start of when the first aquatic type creature existed and also before this if these body plans were produced relatively sudden in evolutionary terms in the Cambrian explosion.

According to this model, (a) the Universal Genome that encodes all major developmental programs essential for various phyla of Metazoa emerged in a unicellular or a primitive multicellular organism shortly before the Cambrian period; (b) The Metazoan phyla, all having similar genomes, are nonetheless so distinct because they utilize specific combinations of developmental programs. This model has two major predictions, first that a significant fraction of genetic information in lower taxons must be functionally useless but becomes useful in higher taxons, and second that one should be able to turn on in lower taxons some of the complex latent developmental programs, e.g. a program of eye development or antibody synthesis in sea urchin. An example of natural turning on of a complex latent program in a lower taxon is discussed.
http://www.tandfonline.com/doi/abs/10.4161/cc.6.15.4557#.VaEEzbUoTfc

This is somewhat vague. If we keep going back, then you're interests in...developmental programs would end up going back into the precambrian days of evolution. Which seems irrelevant as it pertains to other forms of life that we have been discussing, such as zebras and people.

Please refer to the above answer

The Neanderthal extinction was likely influenced by the presence of mankind. Much like many other extinctions in recent times. To some extent, they were probably out-competed. In which case again, it would reflect superior fitness and exceptional predation and influence by something more fit, more than the extinction would necessarily be driven by something like the accumulation of deleterious mutations. Some suggest that climate-change also weighted in to their outcome.

Yet funny enough some say it was the Neanderthals that were stronger and more fit than modern humans. Anyway, I would have thought that even a smaller group could have survived and repopulated. But nevertheless, as many have shown small populations are more susceptible to the accumulation of harmful mutations and this perhaps caused their downfall in the end otherwise they could have replenished the population with time. They probably got many diseases and died out.

Hypotheses on the fate of the Neanderthals include violence from encroaching anatomically modern humans,[3] parasites and pathogens, competitive replacement, competitive exclusion, extinction by interbreeding with early modern human populations,[4] and failure or inability to adapt to climate change. It is unlikely that any one of these hypotheses is sufficient on its own; rather, multiple factors probably contributed to the demise of an already widely-dispersed population.[5][6]

Yes, there is a lot of speculation in that article but it also mentions that Neanderthals suffered from diseases.

According to one study Neanderthals did carry harmful mutations and passed these on to modern humans when they interbred and we are still being affected by these though many have been eradicated out of the population. So this was probably a sign that Neanderthals were slowly dying out through many diseases as well due to their smaller populations and inbreeding.

The Neanderthal genome included harmful mutations that made the hominids around 40 percent less reproductively fit than modern humans, according to new estimates. Non-African humans inherited some of this genetic burden when they interbred with Neanderthals, though much of it has been lost over time. The results suggest that these harmful gene variants continue to reduce the fitness of some populations today.
Inbred Neanderthals left humans a genetic burden: Non-African human populations today have marginally lower fitness thanks to Neanderthal inheritance

 

[stevevw]

" Logic tells us if most vertebrates had small populations when they were first evolving and branching off into new species then they must have also been subject to higher rates of harmful mutations."

To demonstrate this idea, you would need two papers. One to suggest a particular population size in which species would likely go extinct due to deleterious mutations, and you would need another paper discussing population sizes of early vertebrates. Neither of which have I seen posted in this discussion.

I think if you go back through the numourous papers I have linked you will find support for this. It is common knowledged that smaller populations and especially complex creatures (vertebrates) are more supceptable to the effects of harmful mutations. Just doing a quick check I found one.

Multicellular species experience reduced population sizes, reduced recombination rates, and increased deleterious mutation rates, all of which diminish the efficiency of selection (13). It may be no coincidence that such species also have substantially higher extinction rates than do unicellular taxa (47, 48).
http://www.pnas.org/content/pnas/104/suppl_1/8597.full.pdf

But here are some more that I found in doing some research.
With a small effective population size, random genetic drift is more important than selection in determining the fate of new alleles. Small populations therefore accumulate deleterious mutations.
https://onlinelibrary.wiley.com/doi/abs/10.1111/j.0014-3820.2000.tb01232.x

A population with relatively fewer individuals, however, will have lower fitness on average, not only because fewer beneficial mutations arise, but also because deleterious mutations are more likely to reach high frequencies through random genetic drift. This shift in the balance between fixation of beneficial and deleterious mutations can result in a decline in the fitness of individuals in a small
population and, ultimately, may lead to the extinction of that population.
http://pure.iiasa.ac.at/id/eprint/7385/1/IR-04-064.pdf

These patterns are consistent with the view that most mutations are deleterious, adaptive
substitutions are rare, and that smaller populations experience elevated rates of slightly
deleterious substitution than larger populations as a result of genetic drift.
http://robertlanfear.com/publications/assets/Lanfear_etal_TREE_2014.pdf

Most notably, empirical evidence indicates that mutation rates are elevated in multicellular species relative to unicellular eukaryotes and prokaryotes, even on a per-cell division basis, despite the need for the avoidance of somatic damage and the accumulation of germline mutations. Here it is suggested that multicellularity discourages selection against weak mutator alleles for reasons associated with both the cellular and the population-genetic environments, thereby magnifying the vulnerability to somatic mutations (cancer) and increasing the risk of extinction from the accumulation of germline mutations.

Third, an apparently unavoidable impediment to the evolution of low mutation rates in multicellular species is simply the general reduction in effective population size (Ne) in organisms with large somas (Lynch 2007), which will necessarily magnify the vulnerability of mutator alleles to fixation by random genetic drift.
The Cellular, Developmental and Population-Genetic Determinants of Mutation-Rate Evolution

As most multicellular life have smaller populations and vertebrates are multicellular life it stands to reason that vertebrates experience higher rates of harmful mutations.

 

[Job 33:6]

As we know the sudden appearance of most if not all phylum and basic body plans occurred in the Cambrian period. Did the instructions for these body plans come from nowhere or were there some sort of code that produces these. Despite the differences in form from the modern animals like Zebras to the Cambrian creatures, the Zebras basic body plan stems from the body plans that first appeared in the Cambrian period. So the developmental programs for these body plans must have been around from a very early time with the first creatures.

Perhaps it has been a case of the switching on and off of the particular genetic info for all body plan features to produce the different life forms ie limbs are similar despite whether they are fins of legs/arms so it is a case of a variation of the same basic body plan. As noted in embryology all life seems to develop along similar lines as though cast from the same mould and then will change in their fetus development according to that particular creature. This must have been in place from the start of when the first aquatic type creature existed and also before this if these body plans were produced relatively sudden in evolutionary terms in the Cambrian explosion.

According to this model, (a) the Universal Genome that encodes all major developmental programs essential for various phyla of Metazoa emerged in a unicellular or a primitive multicellular organism shortly before the Cambrian period; (b) The Metazoan phyla, all having similar genomes, are nonetheless so distinct because they utilize specific combinations of developmental programs. This model has two major predictions, first that a significant fraction of genetic information in lower taxons must be functionally useless but becomes useful in higher taxons, and second that one should be able to turn on in lower taxons some of the complex latent developmental programs, e.g. a program of eye development or antibody synthesis in sea urchin. An example of natural turning on of a complex latent program in a lower taxon is discussed.
http://www.tandfonline.com/doi/abs/10.4161/cc.6.15.4557#.VaEEzbUoTfc

Please refer to the above answer

Yet funny enough some say it was the Neanderthals that were stronger and more fit than modern humans. Anyway, I would have thought that even a smaller group could have survived and repopulated. But nevertheless, as many have shown small populations are more susceptible to the accumulation of harmful mutations and this perhaps caused their downfall in the end otherwise they could have replenished the population with time. They probably got many diseases and died out.

Yes, there is a lot of speculation in that article but it also mentions that Neanderthals suffered from diseases.

According to one study Neanderthals did carry harmful mutations and passed these on to modern humans when they interbred and we are still being affected by these though many have been eradicated out of the population. So this was probably a sign that Neanderthals were slowly dying out through many diseases as well due to their smaller populations and inbreeding.

The Neanderthal genome included harmful mutations that made the hominids around 40 percent less reproductively fit than modern humans, according to new estimates. Non-African humans inherited some of this genetic burden when they interbred with Neanderthals, though much of it has been lost over time. The results suggest that these harmful gene variants continue to reduce the fitness of some populations today.
Inbred Neanderthals left humans a genetic burden: Non-African human populations today have marginally lower fitness thanks to Neanderthal inheritance

Regarding the first section, It still sounds like youre opening up discussions about evolution as it pertains to pre-cambrian organisms. This seems like it is worth a different discussion than the evolution of things like zebras or neanderthals.

Regarding your second point, youre still being vague. You aren't really providing any information which suggests detrimental mutations as the driver of extinction of neanderthals.

 

[Job 33:6]

I think if you go back through the numourous papers I have linked you will find support for this. It is common knowledged that smaller populations and especially complex creatures (vertebrates) are more supceptable to the effects of harmful mutations. Just doing a quick check I found one.

Multicellular species experience reduced population sizes, reduced recombination rates, and increased deleterious mutation rates, all of which diminish the efficiency of selection (13). It may be no coincidence that such species also have substantially higher extinction rates than do unicellular taxa (47, 48).
http://www.pnas.org/content/pnas/104/suppl_1/8597.full.pdf

Well, just looking at your first paper here,

Here is my post
"a particular population size in which species would likely go extinct due to deleterious mutations, and you would need another paper discussing population sizes of early vertebrates. "

The paper you're referring to doesn't say anything about what population sizes would likely go extinct due to deleterious mutations. Nor does it state anything about...population sizes in early vertebrates that would fall under such a population size.


If we actually look at sources 47 and 48, both sources really dont have anything to do with deleterious mutations as a driver of extinction at all.

 

[stevevw]

Regarding the first section, It still sounds like you're opening up discussions about evolution as it pertains to pre-cambrian organisms. This seems like it is worth a different discussion than the evolution of things like zebras or neanderthals.

I was only responding to you mentioning life being traced back to the pre-Cambrian period. I am just answering that by saying that whatever the life was in that period it seems to have had all the genetic info for the Cambrian period which produced all the known phylum and today's body plans relatively quick in evolutionary terms. So whether we are talking about Zebras or fish they seem to have been the result of variations of the same developmental programs.

Any ability for the zebra and fish to develop limbs to be quick were the result of pre-existing developmental programs and not some random mutation. Natural selection did not have to select for these limbs as they were the best and only choice being produced. Random mutations try to undermine what has been determined as best with these limbs and other features from development and natural selection just maintain the current status. There is no evidence of any experimentation of vertebrates having 5, 6 or 8 limbs to be faster. All complex life was created with 4 limbs and that was the first and only choice which points to the code of life being pre-determined and specific and not the result of random gradualism.

Regarding your second point, you're still being vague. You aren't really providing any information which suggests detrimental mutations as the driver of extinction of neanderthals.

I think I have. I have provided support showing small populations suffer from detrimental mutations and I have shown that vertebrates which include Neanderthals experience small populations. I have provided support showing one of the causes for the downfall of Neanderthals was disease which they passed onto modern humans which effect fitness levels. So Neanderthals were suffering from harmful mutations which they passed onto humans before they went extinct.

Nevertheless, I will spell it out further. Here is some further support which seems to verify the logic.

The Neanderthal genome included harmful mutations that made the hominids around 40 percent less reproductively fit than modern humans, according to new estimates.
In small populations, like the Neanderthals', natural selection is less effective and chance has an outsized influence. This allows weakly harmful mutations to persist, rather than being weeded out over the generations.
The results also have implications for conserving endangered species. Many vulnerable populations in fragmented habitats face similar genetic problems to the Neanderthals: inbreeding, low genetic diversity, and accumulation of harmful mutations.
Inbred Neanderthals left humans a genetic burden: Non-African human populations today have marginally lower fitness thanks to Neanderthal inheritance

So due to the accumulation of harmful mutations because of small populations, Neanderthals were 40% less reproductively fit. That equates to even smaller populations, more inbreeding, more harmful mutations and eventually extinction. That is the premise of evolution theory which is to survive to reproduce. Neanderthals were not surviving to reproduce.

The above article is also stating that not only do Neanderthals suffer the consequences of accumulated slightly harmful mutations because of smaller populations but so do many other endangered species who are cut off or diverged into smaller populations. Endangered implying that they will inevitably die out.

We find that the bulk of purifying selection against Neanderthal ancestry is best understood as acting on many weakly deleterious alleles. We propose that the majority of these alleles were effectively neutral—and segregating at high frequency—in Neanderthals, but became selected against after entering human populations of much larger effective size. While individually of small effect, these alleles potentially imposed a heavy genetic load on the early-generation human-Neanderthal hybrids. This work suggests that differences in effective population size may play a far more important role in shaping levels of introgression than previously thought.
The Strength of Selection against Neanderthal Introgression

So it seems that Neanderthals experienced harmful mutations and passed them on to modern humans but the difference in the two populations was that because humans had larger populations natural selection was able to select against these slightly deleterious mutations. As Neanderthals had smaller populations they were not able to do the same and therefore suffered as a consequence.

 

[stevevw]

Well, just looking at your first paper here,

Here is my post
"a particular population size in which species would likely go extinct due to deleterious mutations, and you would need another paper discussing population sizes of early vertebrates. "

The paper you're referring to doesn't say anything about what population sizes would likely go extinct due to deleterious mutations. Nor does it state anything about...population sizes in early vertebrates that would fall under such a population size.


If we actually look at sources 47 and 48, both sources really dont have anything to do with deleterious mutations as a driver of extinction at all.

And the other 4 papers, do they meet the requirement. The first paper still states clearly that multicellular life experiences smaller populations, higher deleterious mutation rates and extinction rates. And this is supported by the papers of 47 and 48 regardless of what the overall paper is about.

Besides the point is probably being over stated now. Whether it is extinction or harm I am just making the point that mutations are more likley to cause harm in evolution and that natural selection is more likley to maintain existing genetic info by purging out any harmful mutations that undermine it.