Remarkably well-preserved 18,000-year-old puppy found frozen in Siberia

[Speedwell]

No it isn't. Evolution is random. Selective breeding is intentional and purposeful not random. They are nothing alike. Humans being part of the environment is irrelevant to the point. Organisms do not evolve to fit the environment. Organisms randomly evolve and sometimes those evolved traits are beneficial for survival in the environment. Sometimes they are not. Sometimes they are harmful to survival.

Emphasis added. To be correct you would have to substitute "vary" and "varied" for "evolve" and "evolved." Evolution is a consequence of variation and selection
Which is the same whether the selection criteria are being determined by the environment or by the human breeder. The only difference is that the human breeder will also often intervene in mate selection.

 

[Speedwell]

Random is the opposite of intentional. So they are as alike as opposites can be.

Only in popular speech. Used in scientific discourse, including evolutionary biology, the term "random" has a much stricter definition. It means "unpredictable." Used by scientists, the term "random" carries no implications whatever about intention or purpose.

 

[grasping the after wind]

Emphasis added. To be correct you would have to substitute "vary" and "varied" for "evolve" and "evolved." Evolution is a consequence of variation and selection
Which is the same whether the selection criteria are being determined by the environment or by the human breeder. The only difference is that the human breeder will also often intervene in mate selection.

No vary and varied would not be accurate. Of course organism vary and the various traits that those various organisms possess will make a difference in survival. However, that is not what I was attempting to say as that is too general a statement. We are speaking of individual species being bred for traits vs individual species acquiring random traits not of the whole spectrum of variation in nature. If you prefer the words mutate or mutation to evolve or evolution then substitute that but not vary and varied as general variation in traits is not what I am speaking of. In any case, evolution and selective breeding are nothing alike. One is random and the other is not. Selective breeding is simply the encouragement of already known traits that are attractive to humans. With evolution, random mutations cause new traits to appear that may or may not be beneficial to the survival of the organism.

 

[grasping the after wind]

Only in popular speech. Used in scientific discourse, including evolutionary biology, the term "random" has a much stricter definition. It means "unpredictable." Used by scientists, the term "random" carries no implications whatever about intention or purpose.

How does scientific discourse differ from popular speech in that regard ? Do you contend that in popular speech people speak of random as intention or purpose?

 

[essentialsaltes]

If you prefer the words mutate or mutation to evolve or evolution then substitute that but not vary and varied as general variation in traits is not what I am speaking of.

Too bad, because that's what Darwin talked a lot about, and is firmly a part of evolution.

CHAPTER II. VARIATION UNDER NATURE.

 

[Speedwell]

How does scientific discourse differ from popular speech in that regard ? Do you contend that in popular speech people speak of random as intention or purpose?

You said:

Random is the opposite of intentional. So they are as alike as opposites can be.

What I am telling you is that in science the opposite of "random" is "predictable," not "intentional." In science, the term "random" says nothing whatever about intention or purpose, one way or the other. In fact, in some engineering applications, random processes exactly like those in evolution are employed. Nobody would say they were unintentional.

 

[pitabread]

Evolution is random. If you don't believe that ask Darwin.

Darwin's been dead for a few years. Might be difficult asking his opinion at this juncture.

Regardless, I'm talking about selective pressures and the fact that it is possible to predict shifts in allele frequencies over time.

Do you understanding that selection (whether natural or artificial) is merely a part of the process of evolution? Do understand what allele frequencies are and how different selective pressures might influence them?

If you really want I can start citing textbooks on the subject, but I want to make sure you understand what I'm talking about first.

 

[stevevw]

Its a Pupsicle

 

[stevevw]

Domestication has led to changes in gene frequencies. It is artificial selection rather than natural selection, but the result is evolution.

If thats the case then despite all the artificial selection we have done with dogs there seems to be a limit as to how far we can change them. We can alter a dogs size, hair color and length, eyes, snout etc but we cannot add features that were not there in the first place. There are limits and in fact the further we try to alter away from the original dogs genetic makeup the more we introduce diseases and changes that affect the dogs fitness.

 

[JackRT]

Starting about 60 years ago the Russians started a still on going experimentation in the domestication of the blue fox. Domestication has led to evolution. The domesticated foxes have lost vertebrae in their tails and they now curl up rather than down, the ears no longer stand up and their coats are becoming piebald to name a few.

 

[Speedwell]

If thats the case then despite all the artificial selection we have done with dogs there seems to be a limit as to how far we can change them. We can alter a dogs size, hair color and length, eyes, snout etc but we cannot add features that were not there in the first place. There are limits and in fact the further we try to alter away from the original dogs genetic makeup the more we introduce diseases and changes that affect the dogs fitness.

Which is exactly what the theory of evolution predicts. The forced selection of intentional breeding depletes the information content of the gene pool faster than natural selection--faster than it can be replenished by natural means, so the random variation on which both evolution and intentional breeding depend becomes erratic and gradually ceases, preventing further change.

 

[stevevw]

Which is exactly what the theory of evolution predicts. The forced selection of intentional breeding depletes the information content of the gene pool faster than natural selection--faster than it can be replenished by natural means, so the random variation on which both evolution and intentional breeding depend becomes erratic and gradually ceases, preventing further change.

The point I was making was doesn't that mean despite breeders trying to add a new trait that is not there to begin with they cannot. They can only manipulate existing features. Therefore they could never create a dog the size of a cow or a dog with antlers. Artificial breeding can als show the limits of evolution in the wild. No amount of wild breeding will produce anything but a dog.

 

[pitabread]

The point I was making was doesn't that mean despite breeders trying to add a new trait that is not there to begin with they cannot. They can only manipulate existing features.

Except new traits do appear. This has been documented in analysis of canine lineages, for example, where alleles have been identified specific to domesticated dogs.

Therefore they could never create a dog the size of a cow or a dog with antlers.

Taxanomically speaking any descendants of modern dogs will still be dogs. Organisms can't escape their own ancestry in that respect.

At the same time there is nothing in principle preventing future descendants from evolving to become larger or developing antler-like structures.

 

[Speedwell]

The point I was making was doesn't that mean despite breeders trying to add a new trait that is not there to begin with they cannot. They can only manipulate existing features. Therefore they could never create a dog the size of a cow or a dog with antlers. Artificial breeding can als show the limits of evolution in the wild. No amount of wild breeding will produce anything but a dog.

It might produce a dog the size of a cow or a dog with antler like structures, but whatever it was it would still be a dog. And no, artificial breeding does not show the limits of evolution. All it shows is what happens when you deplete the information content of the gene pool faster than it can replenish itself.

 

[FrumiousBandersnatch]

No amount of wild breeding will produce anything but a dog.

The same applies to captive breeding. That's true of all evolution. When two breeding populations of the same species become sufficiently different, e.g. they no longer interbreed, we will call them separate species - they're still both sub-species of the original species. We label the historical tree of such branchings (the 'Tree of Life') retrospectively with taxonomic names at various levels, so we can talk about particular branches at all levels without confusion.

 

[stevevw]

Starting about 60 years ago the Russians started a still on going experimentation in the domestication of the blue fox. Domestication has led to evolution. The domesticated foxes have lost vertebrae in their tails and they now curl up rather than down, the ears no longer stand up and their coats are becoming piebald to name a few.

I would assume that the loss of vertebrates in the tail would be the result evolution because of dogs not using their tail as much. The same as dog ears becoming floppy. But for me this points to a creature being affected by their environment rather than randomly mutating new variation to fit an environment. More like an epigentetic response where the environmental pressure influences genetic expression. So the lack of use of a feature affects the muscles, tissues and cells around that body part and this can influence/activate the genetic makeup for that part of the body in future generations. In this sense it is not due to Ne-Darwinism which randomly produces a variation that happens to be suitable for the environment.

 

[Speedwell]

I would assume that the loss of vertebrates in the tail would be the result evolution because of dogs not using their tail as much. The same as dog ears becoming floppy. But for me this points to a creature being affected by their environment rather than randomly mutating new variation to fit an environment. More like an epigentetic response where the environmental pressure influences genetic expression. So the lack of use of a feature affects the muscles, tissues and cells around that body part and this can influence/activate the genetic makeup for that part of the body in future generations. In this sense it is not due to Ne-Darwinism which randomly produces a variation that happens to be suitable for the environment.

I'm not sure what you mean by "randomly mutating new variation." Random variation is constant, occurring with each generation. It's called "random" because it is randomly distributed (think "bell curve."). Mutation contributes to variation, but is not the sole cause of it.

 

[pitabread]

I would assume that the loss of vertebrates in the tail would be the result evolution because of dogs not using their tail as much. The same as dog ears becoming floppy. But for me this points to a creature being affected by their environment rather than randomly mutating new variation to fit an environment. More like an epigentetic response where the environmental pressure influences genetic expression. So the lack of use of a feature affects the muscles, tissues and cells around that body part and this can influence/activate the genetic makeup for that part of the body in future generations.

[citation needed]

 

[stevevw]

I'm not sure what you mean by "randomly mutating new variation." Random variation is constant, occurring with each generation. It's called "random" because it is randomly distributed (think "bell curve."). Mutation contributes to variation, but is not the sole cause of it.

As far as I understand mutations are random because they do not produce a feature that may be needed for an environment. They just happen and anything that proves useful is preserved by natural selection. So if an offspring needed white fur to camouflage itself in snow country from predators that may or may not happen. It comes down to chance that a mutation will produce that feature. Though random mutation is constant it may not produce the right type of feature needed because it is blind to what is needed.

 

[stevevw]

[citation needed]

Yes no problems. There are a number of mechanisms that can allow living organisms to acquire phenotype changes as posted below. The extended evolutionary synthesis does not see an organism in isolation but something that interacts with other creatures and the environment to be able to share genetic information. The pressures living things experience affect the way they live and respond and how genetic info is expressed.

Evolutionary developmental biology
Some work on developmental bias suggests that phenotypic variation can be channeled and directed towards functional types by the processes of development [27,28]. The rationale is that development relies on highly robust ‘core processes’, from microtubule formation and signal transduction pathways to organogenesis, which at the same time exhibit ‘exploratory behaviour’ [28], allowing them to stabilize and select certain states over others. Exploratory behaviour followed by somatic selection enables core processes to be responsive to changes in genetic and environmental input, while their robustness and conservation maintain their ability to generate functional (i.e. well integrated) outcomes in the face of perturbations. This phenomenon, known as facilitated variation [28,34], provides a mechanistic explanation for how small, genetic changes can sometimes elicit substantial, non-random, well-integrated and apparently adaptive innovations in the phenotype.

Developmental plasticity
Developmental, or phenotypic, plasticity is the capacity of an organism to change its phenotype in response to the environment. Particularly contentious is the contribution of plasticity to evolution through phenotypic and genetic accommodation [27,48,49]. Phenotypic accommodation refers to the mutual and often functional adjustment of parts of an organism during development that typically does not involve genetic mutation [27].

It has long been argued that phenotypic accommodation could promote genetic accommodation if environmentally induced phenotypes are subsequently stabilized and fine-tuned across generations by selection of standing genetic variation, previously cryptic genetic variation or newly arising mutations [27,47,50,51]. From this viewpoint, developmental processes play a critical role in determining which genetic variants will produce selectable phenotypic differences, and which will not. Genetic accommodation may provide a mechanism for rapid adaptation to novel environments, as those environments simultaneously induce and select for alternative phenotypes [47,52,53].

Constructive development
Constructive development refers to the ability of an organism to shape its own developmental trajectory by constantly responding to, and altering, internal and external states [34,71,102–105]. Constructive development goes beyond the quantitative-genetic concept of gene–environment interaction by attending to the mechanisms of development, and emphasizing how gene (expression) and environment are interdependent. As a consequence, the developing organism cannot be reduced to separable components, one of which (e.g. the genome) exerts exclusive control over the other (e.g. the phenotype). Rather, causation also flows back from ‘higher’ (i.e. more complex) levels of organismal organization to the genes (e.g. tissue-specific regulation of gene expression) (figure 1). Constructive development does not assume a relatively simple mapping between genotype and phenotype, nor does it assign causal privilege to genes in individual development. Instead, the developmental system responds flexibly to internal and external inputs, most obviously through condition-dependent gene expression, but also through physical properties of cells and tissues and ‘exploratory behavior’ among micro-tubular, neural, muscular and vascular systems.

For example, there is no predetermined map for the distribution of blood vessels in the body; rather, the vascular system expands to regions with insufficient oxygen supply. Such exploratory processes, commonplace throughout development, are powerful agents of phenotype construction, as they enable highly diverse functional responses that need not have been pre-screened by earlier selection [28,34,106,107].

Within evolutionary biology, development has been traditionally viewed as under the direction of a genetic program (e.g. ‘all of the directions, controls and constraints of the developmental machinery are laid down in the blueprint of the DNA genotype as instructions or potentialities' [108, p. 126]). While the terminology of contemporary biologists is typically more nuanced, Moczek [109] shows that genetic ‘blueprint’, ‘program’ or ‘instructions' metaphors remain widespread in evolutionary biology texts. By contrast, the EES regards the genome as a sub-system of the cell designed by evolution to sense and respond to the signals that impinge on it [8]. Organisms are not built from genetic ‘instructions’ alone, but rather self-assemble using a broad variety of inter-dependent resources. Even where there is a history of selection for plasticity, the constructive development perspective entails that prior selection under-determines the phenotype response to the environment.

Reciprocal causation
By contrast, the Extended Evolutionary Synthesis (EES) views reciprocal causation to be a typical, perhaps even universal, feature of evolving and developing systems, characterizing both the developmental origin of phenotypic variation and its evolution in response to changeable features of its environment [27,71,73]. This clearly differs from Mayr's [89] strict separation of proximate and ultimate causation, and his corollary that ontogenetic processes are relevant only to proximate causation [90].

Inclusive inheritance
In addition, recent research reveals that vertical and horizontal social transmission is widespread in both vertebrates and invertebrates, and can both initiate population divergence and trigger speciation [66]. Under this broader notion of heredity, inheritance can occur from germ cell to germ cell, from soma to germ cell, from soma to soma, and from soma to soma via the external environment [63], which may provide opportunities for some acquired characteristics to be inherited.
https://royalsocietypublishing.org/doi/full/10.1098/rspb.2015.1019#ref-25