Macroevolution:

[tevans9129]

How do you explain thousands of fossils, in chronolgical order, that show a clear gradual development from Eohippus to the modern horse?

Adaptation...possibly, or, an extinct and separate animal. Is Eohippus considered to be in the "horse" family? What species did the Eohippus evolve from, something that can be proven?

 

[lesliedellow]

Thanks. Let's go from there. How do molecules rearrange themselves to accomplish evolution?

I would suggest asking a biologist, such as sfs, if you really want to know how and why mistakes are made in copying the DNA molecule during reproduction.

 

[OldWiseGuy]

As for a "macro change", that is by definition the result of a set of changes, since macro is the accumulation of micro over the generations.

So a "set" of changes contains more than 1. It is the individual changes that I'm interested in, much like the small changes to a vehicle as it travels down an assembly line. I also want to know where the parts came from, and the material for those parts, how they got there, etc.

 

[DogmaHunter]

They are still "horses" just like a wolf and a chiwawa are still "dogs".

If horses would produce non-horses, evolution theory would be falsified.

Learn the theory you are insisting on arguing against. For the upteenth time.

 

[DogmaHunter]

So a "set" of changes is more than 1.

Yes, but changing the goalposts like this, doesn't invalidate my answers.

You didn't ask about MACRO changes. You asked about mere change in an organ, tissue, cells, etc. You made no mention of any "macro" stuff. And if you would, I'ld ask you to define it first.

A single mutation demonstrably has at least the potential to bring about change in a multitude of ways and that's a perfectly valid answer to the question that you DID ask.

The effects of mutations

 

[OldWiseGuy]

Yes, but changing the goalposts like this, doesn't invalidate my answers.

You didn't ask about MACRO changes. You asked about mere change in an organ, tissue, cells, etc. You made no mention of any "macro" stuff. And if you would, I'ld ask you to define it first.

A single mutation demonstrably has at least the potential to bring about change in a multitude of ways and that's a perfectly valid answer to the question that you DID ask.

The effects of mutations

My questions, however clumsy, ask the same thing. What causes change?

 

[Jimmy D]

Speculations, conjecture, most likely, it is believed, artistic renderings of what might have been, is that provable fact?

We have thousands of skeletons showing, chronologically, the development from eohippus to modern horse, they are not "artistic renderings".

Horse Evolution Over 55 Million Years

[The eohippus is an extinct prehistoric animal that is known as the “dawn horse.” It lived in the early Eocene era, about 50 million years ago. It probably looked like a miniature, spotted, cloven horse and was bigger than a fox. It was probably the size of a small dog, with a small thin tail. It lived in swamp-like forests, hid from predators in the shadows, and lived off the leaves of bushes and short trees. As time went by, eohippus changed. But for 20 million years, it didn’t change that much, evolutionarily speaking. Flash forward in time to a moment slightly before ours. There now exist paleobiologists. For many decades, they considered Eohippus to be the linear ancestor of Equus, the modern day horse.

For many decades, scientists considered Eohippus the ancestor of the modern-day horse.

Then new science replaces old science, and this idea changes. New science explains that the evolution of the horse is non-linear, like a many-branched tree. Equus happens to be the only branch of the horse now in existence. Eohippus is still considered an ancestor of Equus, but in a less linear way. For some reason, scientists seem to know more about the evolutionary lineage of the horse than any other animal.

Extinct equids. True to scale.

Also, there is now the idea that Equus is not the goal, or the crowning jewel, of a naturally-selected lineage.

As part of this many-branched tree, the indigenous horse died out in North America about 12,000 years ago. The Spanish brought domestic horses to the New world at the end of the 1400s. Therefore, if you encounter wild horses in the United States, they are feral.]

In what way does that poorly worded opinion piece, address what I posted about the evolution of the horse? If anything it confirms what I posted.

Do you agree with the article that the evolution of the horse is non linear and multi-branched? That Eohippus is the ancestor of the modern horse?

They are still "horses" just like a wolf and a chiwawa are still "dogs".

Eohippus is not a horse any more than a tapir is.

 

[tevans9129]

Fine, ask away.

I did, what good did it do?

"I do not understand your, "a particular set of unknown restraints", comment, do you see a request for both parties to answer all questions they may be asked as "restraints"? Am I asking someone to agree to something that I am not willing to agree to?"

Should I provide the definition of "all" that I am using?

 

[Jimmy D]

Adaptation...possibly, or, an extinct and separate animal. Is Eohippus considered to be in the "horse" family? What species did the Eohippus evolve from, something that can be proven?

Is there a difference between adaptation and evolution?

I don't know what came before Eohippus.

 

[DogmaHunter]

My questions, however clumsy, ask the same thing. What causes change?

The causes of mutations
What is a gene mutation and how do mutations occur?

 

[OldWiseGuy]

The causes of mutations
What is a gene mutation and how do mutations occur?

When did organisms first start making genetic copies of themselves?

 

[Jimmy D]

I did, what good did it do?

"I do not understand your, "a particular set of unknown restraints", comment, do you see a request for both parties to answer all questions they may be asked as "restraints"? Am I asking someone to agree to something that I am not willing to agree to?"

Should I provide the definition of "all" that I am using?

Whatever floats your boat mate.

 

[tevans9129]

Is there a difference between adaptation and evolution?

I don't know what came before Eohippus.

"Is Eohippus considered to be in the "horse" family?"

Now, do you see why I ask people to agree to answer all questions in any serious discussion of a subject" Some questions may be a little inconvenient to answer so they are ignored, deflected from or just spinned until the one asked becomes dizzy and forgets the qustion.

My definition in common English terms...

Adaptation - changes to one's environment within in the same species for survival purposes.

Evolution - one species changing into a totally different species.

Transition - depends on the context.

Speciation - one species to a distinctly different species...evolution.

Care to share your definitions?

 

[tevans9129]

Whatever floats your boat mate.

Not the least bit surprised with that response, I have read billllllions of like species.

 

[Jimmy D]

"Is Eohippus considered to be in the "horse" family?"

Now, do you see why I ask people to agree to answer all questions in any serious discussion of a subject" Some questions may be a little inconvenient to answer so they are ignored, deflected from or just spinned until the one asked becomes dizzy and forgets the qustion.

Oh ok, no problem.

In answer to your question it is in the taxonomic grouping equidae. They are however in a different genus.

My definition in common English terms...

Adaptation - changes to one's environment within in the same species for survival purposes.

Evolution - one species changing into a totally different species.

Transition - depends on the context.

Speciation - one species to a distinctly different species...evolution.

Care to share your definitions?

I asked because I don't really understand what arbitary line you are drawing between "adaptation" and "evolution". If two populations become isolated from one another and are exposed to different selective pressures could they not adapt enough to become different species given enough time?

 

[Jimmy D]

Adaptation...possibly, or, an extinct and separate animal. Is Eohippus considered to be in the "horse" family? What species did the Eohippus evolve from, something that can be proven?

We now have enough fossils of enough species in enough genera to examine subtle details of evolutionary change, such as modes of speciation.

• 
  
  
  • Tracing a line of descent from Hyracotherium to Equus reveals several apparant trends: reduction of toe number, increase in size of cheek teeth, lengthening of the face, increase in body size. But these trends are not seen in all of the horse lines. On the whole, horses got larger, but some horses (Archeohippus, Calippus) then got smaller again. Many recent horses evolved complex facial pits, and then some of their descendants lost them again. Most of the recent (5-10 My) horses were three-toed, not one-toed, and we see a "trend" to one toe only because all the three-toed lines have recently become extinct.
    
    Additionally, these traits do not necessarily evolve together, or at a steady rate. The various morphological characters each evolved in fits and starts, and did not evolve as a suite of characters. For example, throughout the Eocene, the feet changed little, and only the teeth evolved. Throughout the Miocene, both feet and teeth evolved rapidly. Rates of evolution depend on the ecological pressures facing the species.
    
    The "direction" of evolution depends on the ecological challenges facing the individuals of a species and on the variation in that species, not on an inherent "evolutionary trend".

• 
  
  
  • New species can arise through several different evolutionary mechanisms.
    
    Sometimes, new species split off suddenly from their ancestors (e.g., Miohippus from Mesohippus) and then co-existed with those ancestors. Other species came into being through anagenetic transformation of the ancestor, until the ancestor had changed appearance enough to be given a new name (e.g. Equus from Dinohippus). Sometimes only one or a few species arose; sometimes there were long periods of stasis (e.g. Hyracotherium throughout the early Eocene); and sometimes there were enormous bursts of evolution, when new ecological opportunities arose (the merychippine radiation). Again, evolution proceeds according to the ecological pressures facing the individuals of a species and on the variation present within that species. Evolution takes place in the real world, with diverse rates and modes, and cannot be reduced to a single, simple process.

2My Old & New World Equus
\ | /
\ | /
4My Hippidion Equus Stylohipparion
| | Neohipparion Hipparion Cormohipparion
| | Astrohippus | | |
| | Pliohippus ---------------------------
12My Dinohippus Calippus \ | /
| | Pseudhipparion \ | /
| | | |
------------------------------------------- Sinohippus
15My \ | / |
\ | / Megahippus |
17My Merychippus | |
| Anchitherium Hypohippus
| | |
23My Parahippus Anchitherium Archeohippus
| | |
(Kalobatippus?)-----------------------------------------
25My \ | /
\ | /
|
35My |
Miohippus Mesohippus
| |
40My Mesohippus
|
|
|
45My Paleotherium |
| Epihippus
| |
Propalaeotherium | Haplohippus
| | |
50My Pachynolophus | Orohippus
| | |
| | |
------------------------------
\ | /
\ | /
55My Hyracotherium

Horse Evolution

...............................................

I'm curious as to why you think that these hundreds of species may have arisen separately, we can clearly observe many species of Equidae appearing in the fossil record with slight differences to preceding species chronolgically. All those changes add up to quite a difference over longer periods of time. Modern horses are not only a different species but a different genus.

 

[tevans9129]

Horse Evolution

Bolded for attention.

We have very different views of the subject Jimmy and the only way that you can convince me that my views are incorrect is to ask me questions that I cannot give plausible, clear, verifiable answers to. OTOH, you cannot convince me that your views are correct unless you can answer every question that I may ask with the same kind of answers.

With that being said, I will enthusiastically engage in a serious discussion with you on the subject if you will agree to that simple request with an honest intent to honor the agreement. What say you?

IF, we were talking about creation and the only source I would accept as authentic and the only sources that I quoted were from Bible believing Christian sites, would you accept my data without question?

 

[tevans9129]

There are many different breeds but they are still horses.

"Dawn horse (genus Hyracotherium), extinct group of horses that flourished in North America and Europe during the early part of the Eocene Epoch (55.8–33.9 million years ago). Even though these animals are more commonly known as Eohippus, a name given by the American paleontologist Othniel Charles Marsh, they are properly placed in the genus Hyracotherium, the name given earlier by British paleontologist Richard Owen."

So what did the Hyracotherium "evolve" from, what evidence that can be verified?

 

[Subduction Zone]

Bolded for attention.



IF, we were talking about creation and the only source I would accept as authentic and the only sources that I quoted were from Bible believing Christian sites, would you accept my data without question?

But you can't verify any of your answers when pressed. Does that not mean that you should admit that you are wrong?

 

[pitabread]

There are many different breeds but they are still horses.

I never understood this whole "they are still whatever" reasoning when it comes to evolution. The whole point of biological evolution is that things change. That we see examples of life clearly changing and evolving over time is what validates that biological evolution is real.

Arguably the species barrier is the only true biological barrier in terms of gene flow, so once you get speciation the rest is just compounded change thereafter.