Evolution conflict and division

[The Barbarian]

This reminds me of the 'lumpers and splitters' in taxonomy. Lumpers see any variation as within the species and splitters will see variations as a new species.

Good observation. If there were no evolution, we would see nice, discrete species with no in-between cases. But as Darwin pointed out, evolution would result in all sorts of intermediate cases. It's one of the reasons scientists accept Darwin's theory.

 

[The Barbarian]

Evolution theory is less an empirical science than an historiographical one.

Let's take a look. Darwin's theory:
1. More are born than can survive long enough to reproduce.
2. Every individual is slightly different than its parents.
3. Some of these differences affect likelihood of surviving to reproduce.
4. The useful differences tend to be retained in the population and the harmful ones tend to be removed, and this sometimes
leads to speciation.

Which of these are not observed? Right. Again, I suspect confusion between evolution and common descent.

Apparently you do not understand the principle. Common descent is not the issue that violates this principle: only devolution is possible, a loss of functionality.

Would you like to learn about a directly observed evolution of a new function? Even most YECs no longer deny that fact.

 

[stevevw]

Good observation. If there were no evolution, we would see nice, discrete species with no in-between cases. But as Darwin pointed out, evolution would result in all sorts of intermediate cases. It's one of the reasons scientists accept Darwin's theory.

I agree with the observations but not necessarily with how they came about. For example we can say a creature may end up evolving by adaptations to an environment but it not necessarily being from beneficial random mutations and natural selection.

But rather may primarily be the result of non random changes and the creations selection rather than natural selection. As though the creature itself was the director of its own evolution. Either through its own natural knowledge of nature and how to change environments to suit them.

Or through developmental bias and plasticity where pre existing genetic info is able to produce coordination and adaptable changes that are designed to help them adapt.

 

[The Barbarian]

I agree with the observations but not necessarily with how they came about. For example we can say a creature may end up evolving by adaptations to an environment but it not necessarily being from beneficial random mutations and natural selection.

There may be some lucky hits, but adaptation usually requires a number of changes in genome. As observations of the evolution of complex adaptions has shown, both random mutation and natural selection are involved.

Evolution on a Petri Dish

Several years ago I began a project whose major goal was to understand the variety of ways by which an organism can evolve new physiologic functions. How does an organism which is already well adapted to its environment evolve a new function to cope with an altered...

link.springer.com

And evolution happens to populations, not individuals. So a mutation, like the EPAS1 allele that allows Tibetans to survive at high altitudes, must then undergo natural selection in order for it to become fixed or widely established in a population. Darwin's great discovery was the way such adaptations become established in a population.

 

[stevevw]

There may be some lucky hits, but adaptation usually requires a number of changes in genome. As observations of the evolution of complex adaptions has shown, both random mutation and natural selection are involved.

Evolution on a Petri Dish

Several years ago I began a project whose major goal was to understand the variety of ways by which an organism can evolve new physiologic functions. How does an organism which is already well adapted to its environment evolve a new function to cope with an altered...

link.springer.com

I don't think they are lucky hits. I think evolution involves a holistic approach where just about everything that happens is within a broader connected web of influences that all have some effect on how evolution happens.

So I am not sure if there really is completely random mutations in the sense that they were not the result of something unrelated to the creature and its environment. The environmental pressures effect bodies which effect or perhaps activate responses which can trigger genetic changes.

I think a bit like epigenetics but within the regulatory genes. Basically I think all the genetic info is already there. Or rather the developmental mechanisms are capable of crafting well suited responses to enviromental conditions.

A holistic approach assumes that creatures and enviroments are not disconnected and work together. As well as working with other creatures in a web of evolution. But all the ingredients for sustaining life and allowing life to adapt or live together is already in the mix waiting to be utilised.

And evolution happens to populations, not individuals.

Yes but I don't think this explains the unique and different ways creatures can exist within those populations. I think populations genetics is too broad an understanding. It misses a lot of the ways life is its own director of evolution.

So a mutation, like the EPAS1 allele that allows Tibetans to survive at high altitudes, must then undergo natural selection in order for it to become fixed or widely established in a population. Darwin's great discovery was the way such adaptations become established in a population.

Yes and in some ways NS is a cold hard stat. Whatever lives on, lives on.

But I don't think its as simple as NS being some independent force that is doing the selecting. Or even a force that is just left to fate or nature. Its not that simple.

I think at least part of why the mutation that allows someone to adapt to high altitudes or any change that allows someone to adapt to the new envionment is not just a random mistake that happened again and again and theres all these variations of breathability.

I think the environmental pressure such as the difficulty to breath is the trigger for the beginning of the genome to be throwing up solutions for the creature to adapt to said environment.

And I think its specific to that pressure and this acts on the genome in a way that its targeting adaptive changes to that enviroment. Its not luck but a holistic evolution between creatures and environments organically.

You also have the idea that creatures also change environments rather than being changed to the environment. Also genetic plasticity where phenotype can change without genetic change. Then later the genome adapts to that change.

But for the most part genetic changes are the product of existing genetic info. Or the ability of the machinery to generate new responses. Like there is a fair degree of flexibility for creatures of adapt. Or rather the ability of whatever it is that gives life its life. Its not a rigid mathmatical equation but an organic evolution of life.

But much of this is supported with good research.

The extended evolutionary synthesis: its structure, assumptions and predictions

The extended evolutionary synthesis: its structure, assumptions and predictions - PubMed

Scientific activities take place within the structured sets of ideas and assumptions that define a field and its practices. The conceptual framework of evolutionary biology emerged with the Modern Synthesis in the early twentieth century and has since expanded into a highly successful research...

pubmed.ncbi.nlm.nih.gov

By the way I am not a biologist so this is just my take.

 

[The Barbarian]

So I am not sure if there really is are such as the difficulty to breath is the trigger for the beginning of the genome to be throwing up solutions for the creature to adapt to said environment.

That's the idea behind genetic algorithms, used by engineers to solve extremely complex problems. Toss up random changes, and keep whatever works better. The key is that there's more than one mutation in human populations for high-altitude adaptation. Some work better than others.

One of the things people miss (and I think this is what you're talking about) is that populations aren't just passive recepients of the changes of natural seletion. Populations also "push back" and modify environments in ways that affect natural selection.

But for the most part genetic changes are the product of existing genetic info. Or the ability of the machinery to generate new responses.

Right. For example, it would be great to have a second pair of arms. But the basic tetrapod configuration just won't allow the necessary useful transitional forms that would be required to evolve them.

You also have the idea that creatures also change environments rather than being changed to the environment. Also genetic plasticity where phenotype can change without genetic change. Then later the genome adapts to that change.

Yes. It's a complex interaction.