Why aren't animals more homogenous?

[SFNQuestions]

If nature has already discovered it, where is it?

Which is why the title of this topic is "Why aren't there more homogeneous animals?"

[Argent]

Which is why the title of this topic is "Why aren't there more homogeneous animals?"

In the way you have phrased that question your implication is, very strongly, that there are no homogenous animals. It is therefore strange that you now assert that we don't know whether there are any or not. These two positions that you have adopted appear to be contradictory.

[mistermack]

In the end, the question "why hasn't evolution done X" is a particularly futile one.

 

It's like starting a rock rolling down a hill, and asking "why didn't it hit this tree?" at the bottom. Or "why didn't I win the lottery?"

 

If it all started again, the results of evolution would look dramatically different in the same timeframe. Yes, it's a definite process, but it's also hugely random. That's why.

[SFNQuestions]

In the way you have phrased that question your implication is, very strongly, that there are no homogenous animals.

No the way it's phrased indicates that the biological arrangement I'm referencing is rare, though it may non exist or be abundant in discrete locations or very specific classes of species.

 

In the end, the question "why hasn't evolution done X" is a particularly futile one.

 

It's like starting a rock rolling down a hill, and asking "why didn't it hit this tree?" at the bottom. Or "why didn't I win the lottery?"

 

If it all started again, the results of evolution would look dramatically different in the same timeframe. Yes, it's a definite process, but it's also hugely random. That's why.

Yeah it's random but not indefinitely so, there are specific reasons why certain traits weren't passed on and why certain traits were, which all vary for different circumstances.

Edited February 26, 2017 by SFNQuestions

[Bender]

It is not random in the way that large, mobile animals are very likely to have both hard and soft tissue.

 

There is no evolutionary advantage towards more homogeneous, and thus suboptimal, materials for different organs.

[Argent]

No the way it's phrased indicates that the biological arrangement I'm referencing is rare, though it may non exist or be abundant in discrete locations or very specific classes of species.

 

Yeah it's random but not indefinitely so, there are specific reasons why certain traits weren't passed on and why certain traits were, which all vary for different circumstances.

I found it difficult to interpret "Why aren't animals more homogenous" in any way other than, "Animals are not very homogenous, why is this?"

 

What StringJunky just said is what I was struggling to imply in some of my posts. It should really serve to close the discussion, unless you feel it is incorrect.

[SFNQuestions]

I found it difficult to interpret "Why aren't animals more homogenous" in any way other than, "Animals are not very homogenous, why is this?"

 

Which is exactly the way I wanted it to be interpreted.

[Argent]

Which is exactly the way I wanted it to be interpreted.

I give up. Clearly you do not find your contradictory statements to be contradictory, so we'll ascribe it to me being thick and move on.

[Arete]

One of the major benefits of multicellularity is the ability of cells and organs to become specialized. I.e. as compared to a unicellular organism, in which every single cell is an individual which must perform every biological task necessary for the organism to live, the cells/organs in a multicellular organism can specialize in one or more specific roles. The leads to different optimal densities - e.g. a vertebrate has a rigid musculoskeletal system optimised to move around an enviroment, and a liquid blood and lymphatic system to transport compounds throughout the body.

 

Giving up variable density means giving up many of the benefits of multicellularity, and while some organisms do this (e.g. macroalgae, some fungi) they tend to be facultatively multicellular - exploiting some benefits of being both multi and uni cellular.

[mistermack]

I think butterflies and moths are the best animals to study, to illustrate the different problems and advantages of the different body types.

Caterpillars are ideal eating machines. They are just there to eat what is close by. With their soft relatively homogeneous bodies, they are not designed to travel far and wide to find a food source or mate.

But a butterfly with it's stiff levers and strong but light wing material can fly huge distances, both to find a mate, and find an ideal food source for it's caterpillars, after it's eggs hatch.

The same goes for a vast range of insects. So they manage to benefit from the advantages of both body plans in one lifetime, and to negate the disadvantages.

That's why there are so many of them.

[SFNQuestions]

I give up. Clearly you do not find your contradictory statements to be contradictory, so we'll ascribe it to me being thick and move on.

They're not contradictory, you're just refusing to acknowledge that your initial assumptions are wrong. As you ignored multiple times, the intention is the point out that I don't see any animals that fit the description, but in no logical way does my own observation rule out the possibility that such animals may have already existed and gone extinct or currently exist and are niche.

 

One of the major benefits of multicellularity is the ability of cells and organs to become specialized. I.e. as compared to a unicellular organism, in which every single cell is an individual which must perform every biological task necessary for the organism to live, the cells/organs in a multicellular organism can specialize in one or more specific roles. The leads to different optimal densities - e.g. a vertebrate has a rigid musculoskeletal system optimised to move around an enviroment, and a liquid blood and lymphatic system to transport compounds throughout the body.

 

Giving up variable density means giving up many of the benefits of multicellularity, and while some organisms do this (e.g. macroalgae, some fungi) they tend to be facultatively multicellular - exploiting some benefits of being both multi and uni cellular.

Right, no one's disputing that there are benefits to specialized cells, but I'm not saying they can't have blood vessels, I just mean the "skeleton" so to speak doesn't localize, that it extends homogenously from the center to the skin.

Edited February 28, 2017 by SFNQuestions

[Arete]

Right, no one's disputing that there are benefits to specialized cells, but I'm not saying they can't have blood vessels, I just mean the "skeleton" so to speak doesn't localize, that it extends homogenously from the center to the skin.

 

Put simply, it would lose its functionality. A diffuse skeleton wouldn't provide the same level of anatomic structure, capacity for locomotion or protection of vital organs. The increased fibrosity of other tissues would impede their function also.

[CharonY]

I find it hard to visualize what OP envisions, but the closest I can think of are localized increased in viscosity by polymerization of parts of the cytoskeleton as part of certain mobile cells. In almost all complex organisms calcification and other rigid structures that I can think of are used as a frame only serve a function if they are, well rigid and localized.