Ramin Mardfar &  Dr. Simon Maddrell

(July 2008)

A new theory about the reason that why insects body size is small.

1. In the Carboniferous there were insects with a 70 cm wingspan.

2. Insects also have accessory pulsatile organs at bases of limbs and wings to circulate blood into these body parts.

3 Large insects disappeared when vertebrates appeared on land - they were outcompeted.

So insects could be much larger but they compete best

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�       Compare these plants (living) considering their body size and structure
> of fluid circulation system with each other.   
>

Agreed, but correlation does not constitute proof. Consider the alternative
explanation for the undoubted facts you assemble. Small organisms do not
need extensive, and expensive, circulatory systems. If they had them, they
would be out competed by their compatriots who were not so encumbered. Large
Crustaceans have much more complex blood circulatory systems than small
ones and their smaller relatives, the insects. And consider this, flying
insects have much higher metabolic rates per gram than any vertebrate, yet
they have more 'primitive' circulatory systems. If they needed them they
would have evolved them.

See how the same facts can be seen in two opposing ways, but I think any
critical observer, who realized the underlying factors would prefer my
explanation.

If you disagree, how do you explain the fact that there used to be much
larger insects? And how would you explain the fantastically high metabolic
rates of flying insects?

Best wishes,

Simon M

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1) Water flow of river swirls the mill wheel.

2) Swirling the mill wheel of cause�s water flow in river.

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1) Evolution of blood circulation system causes to get enlarged the body size of the animal.

2) Getting enlarged the body size of animal, causes to develop blood circulation system of animal.

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yes ..., insects have accessory hearts. But not all of them. Those who are smaller don't have these organs.

 Some of Gastropods, for example Octopus, have extraneous hearts. So they have the largest body size among mollusks.

 Mammals have an imperfect form of this organ. Some species of mammals will be able to complete these organs of themselves and to enlarge their body size more and create new class of animals in the future.

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>> And how would you explain the fantastically high metabolic
rates of flying insects?

 

High metabolic rates need high oxygen. In the body of insects the required oxygen for high metabolism is carries to the cells by Tracheas and the circulatory system dose not have an important role. This way of carrying oxygen (Tracheae) is only possible in small bodies. But in large bodies the oxygen must be carried by blood.  Despite having a primitive circulatory system, the insects can have a high metabolic rate.

>> How do you explain the fact that there used to be much
larger insects?

Consider the different class of animals and plants. In comparison to now all of them had largest species in the past time. The largest species of Insects, Crustacean, Arachnids, Mollusks, Amphibians, Reptiles, Birds, Mammals, Bryophytes, Club moss, Horsetails are Ferns are now found in fossils.

The reason of all this decreasing of body size is the increasing of gravity.

The gravity was lower in the past, so the circulatory system could overcome it better and made their body size larger.

Sincerely

Ramin

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Dear Ramin,

>>> And how would you explain the fantastically high metabolic
>rates of flying insects?
>
>
> High metabolic rates need high oxygen.

AND they need a fuel supply. In fact they have extremely high blood sugar
levels, so even a sluggish circulation will supply fuel (trehalose or lipid
or proline) fast enough.

n the body of insects the
> required oxygen for high metabolism is carries to the cells by Tracheas
> and the circulatory system dose not have an important role. This way of
> carrying oxygen (Tracheae) is only possible in small bodies.

Not so, the large flying insects that used to exist had tracheae. And even
the largest flying insects now can supply oxygen to their tissues using the
tracheal system. Oxygen diffuses 300,000 times faster in air than in water.
And all large insects circulate the air through the larger tubes of the
tracheal system. So a locust actively breathes, even when not particularly
active. Small insects can rely on diffusion alone, but larger ones must
circulate air through their bodies. That is an example of what I am
claiming. If an animal is to increase in size and needs a change in
physiology to do so, it turns out to have evolved it. So if you just looked
at small insects, you would say, they cannot get any bigger because they
just rely on diffusion. Wrong; the bigger ones have evolved a more
sophisticated system for circulating air. So, by extension, if they were
bigger still, they would evolve ever more effective systems.

But in large
> bodies the oxygen must be carried by blood. Despite having a primitive
> circulatory system, the insects can have a high metabolic rate.
>>> How do you explain the fact that there used to be much
> larger insects? Consider the different class of animals and plants. In
> comparison to now all of them had largest species in the past time. The
> largest species of Insects, Crustacean, Arachnids, Mollusks, Amphibians,
> Reptiles, Birds, Mammals, Bryophytes, Club moss, Horsetails are Ferns are
> now found in fossils. ............................................... I
> am waiting for your opinions. Ramin


The essential point is the one you have identified. Small animals tend to
have less impressive circulatory systems (tho' this does NOT apply to small
mammals. A shrew has a heart rate of 1200 beats per minute and a
super-large heart, to the extent that the left lung is very reduced in size
to accommodate it). Therefore one can say either that this has kept them
small (your view) or that they don't need an impressive circulatory system
so don't go to the expense of constructing one (my view). In general
animals (and plants) are subject to evolutionary selection, which will not
tolerate overly expensive systems. A good example of the latter is the
resistance of fruit flies to parasitoids. If fruit flies are bred in the
lab for many generations with parasitoids (a sort of extreme selection
pressure), the surviving strain is found to have developed a good
resistance to the parasitoid. However, they have done this by raising the
level of blood cells (that overcome the parasitoid). So why haven't fruit
flies in the wild evolved the same high resistance? Answer is that it costs
too much. Resistant fruit flies grow more slowly (they have to spend energy
growing more blood cells) and are outcompeted by their relatives that are
not so encumbered. Another example. More than 80% of old orang-utans in the
wild are found to have suffered a broken limb at one stage in their lives.
Why have they not evolved stronger bones? Answer; it costs too much and
again they are outcompeted by their lighter-boned relatives that can grow
faster and, crucially, reproduce earlier.

Best wishes,

Simon M

 

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Dear Simon Maddrell:

>>If an animal is to increase in size and needs a change in
physiology to do so, it turns out to have evolved it.

(Your view): An insect (any animal or plant) can make his body size as large as an elephant (or any size) at any time it likes and according to its body size, it adapts its circulatory system.

Question 1: Why don�t insects like to be as large as an elephant and not be mashed under the elephant�s feet?

(My view): An insect can�t be as large as an elephant because its circulatory system is incomplete. There isn�t any vessel in insect�s body to stream the blood to long distances because they don�t have the pattern (plan) of building the vessel. No insect likes to be mashed under the elephant�s feet. As soon as they find out how to make the vessel, they will increase their body size.

Pleas answer the following questions using your view point.

Question 2: Why doesn�t a lizard like to be as large as an elephant but an elephant likes to be that big?

Question 3: Why do you think reptiles don�t like to be as large as a dinosaur now but they liked to be that big 100 million years ago?

Question 4: Why doesn�t an elephant like to be as large as a mammoth now but it liked to be that big 2 million years ago?

Question 5: Why doesn�t a horsetail like to be 20 meters tall now but it liked to be that tall 200 million years ago?

Question 6: Why doesn�t a mollusk like to have 4.5 meters diameter now but it (Endocras) liked to be that big 500 million years ago?

Question 7: Why do all the classes of animals and plants liked to have very large species in the past but they don�t like it?

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>>Small animals tend to have less impressive circulatory systems (tho' this does NOT >apply to small mammals.)

Do you mean this (Is this your question):

Why the small mammals, despite having an impressive circulatory system, have a small body size?  A mouse and elephant have a similar circulatory system because both of them are mammals, but their body size is different. Why?

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>>A good example of the latter is the
resistance of fruit flies to parasitoids. If fruit flies are bred in the
lab for many generations with parasitoids (a sort of extreme selection
pressure), the surviving strain is found to have developed a good
resistance to the parasitoid. However, they have done this by raising the
level of blood cells (that overcome the parasitoid). So why haven't fruit
flies in the wild evolved the same high resistance? Answer is that it costs
too much. Resistant fruit flies grow more slowly (they have to spend energy
growing more blood cells) and are outcompeted by their relatives that are
not so encumbered.

There is a similar phenomenon in human�s body. When we climb a mountain, our body increases its red cells because of the low oxygen density (pressure). After descending, it returns to the normal condition. This is not an evolutionary phenomenon. This is only a reaction. It is like the changing of the color of a Chameleon in different places.

Sincerely

Ramin

No, because the flies were bred for MANY generations as I said; they had
evolved. You are confusing this with adaptation which occurs WITHIN a
generation.

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Dear Simon Maddrell:

>>A good example of the latter is the
resistance of fruit flies to parasitoids. If fruit flies are bred in the
lab for many generations with parasitoids (a sort of extreme selection
pressure), the surviving strain is found to have developed a good
resistance to the parasitoid. However, they have done this by raising the
level of blood cells (that overcome the parasitoid). So why haven't fruit
flies in the wild evolved the same high resistance? Answer is that it costs
too much. Resistant fruit flies grow more slowly (they have to spend energy
growing more blood cells) and are outcompeted by their relatives that are
not so encumbered.

There is a similar phenomenon in human�s body. When we climb a mountain, our body increases its red cells because of the low oxygen density (pressure). After descending, it returns to the normal condition. This is not an evolutionary phenomenon. This is only a reaction. It is like the changing of the color of a Chameleon in different places.

A correct example:

There are two different genres among the horses now which are different in their red cell. The draught horses and the race horses. The draught horses have more red cells than the race horses. That is an evolutionary phenomenon. Because this change has happened during many years and this change made to create two different genres of horses. In this example, the changing of place and environment have no effect on the genres. So we see that evolution on the circulation system can separate the animals and change their evolutionary way.

Sincerely

Ramin

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Question 1: Why don�t insects like to be as large as an elephant and not be mashed under the elephant�s feet?

Based on your view; there would be no logical answer for this question according to your view.

Based on my view; an insect can�t be as large as an elephant because its circulatory system is incomplete. There isn�t any vessel in insect�s body to stream the blood to long distances because they don�t have the pattern (plan) of building the vessel. No insect likes to be mashed under the elephant�s feet. As soon as they find out how to make the vessel, they will increase their body size.

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Question 2: Why doesn�t a lizard like to be as large as an elephant but an elephant likes to be that big?

Based on your view; there would be no logical answer for this question according to your view.

Based on my view; the circulatory system of reptiles have 3-chambered heart and is weaker than the circulatory system of the mammals with the 4-chambered heart. So, the largest species of reptiles now are smaller than the largest species of mammals. The mammals now can have species as large as an elephant or a giraffe. But the largest species of the reptiles is crocodile (and they can stand on their foot, they lie on the ground).

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Question 3: Why do you think reptiles don�t like to be as large as a dinosaur now but they liked to be that big 100 million years ago?

Based on your view:  ( ? )

Based on my view: The circulatory system of a reptile now facing the gravity can create the species as long as the crocodiles. (That would be horizontal and on the ground) but 100 million year ago the gravity was low and the reptiles could have species as large as dinosaurs.

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Question 4: Why doesn�t an elephant like to be as large as a mammoth now but it liked to be that big 2 million years ago?

Based on your view:  ( ? )

Based on my view: Because 2 million years ago the gravity was less than now and the circulatory system of mammals could over come it better, so they could create the species like mammoth but now the gravity is more and the circulatory system of mammals can not over come it, so they can not create the species as large as a mammoth.

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Question 5: Why doesn�t a horsetail like to be 20 meters tall now but it liked to be that tall 200 million years ago?

Based on your view:  ( ? )

Based on my view: A horsetail has a weak fluid circulation system and can be only some centimeters in this gravity. But 200 million years ago the gravity was so low that this weak fluid circulation system could over come it. So a horsetail could be 20 meters.

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Question 6: Why doesn�t a mollusk like to have 4.5 meters diameter now but it (Endocras) liked to be that big 500 million years ago?

Based on your view:  ( ? )

Based on my view: Because 500 million years ago the gravity was less than now and the circulatory system of mollusks could over come it better, so they could create the species like Endocras but now the gravity is more and the circulatory system of mollusks can not over come it, so they can not create the species as large as a Endocras.

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Question 7: Why do all the classes of animals and plants liked to have very large species in the past but they don�t like it?

Based on your view:  ( ? )

Based on my view: Because in the past the gravity was less than now.

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Question 8: why the primitive (initial) species of each class were small in size?

 The first mammals were as big as a mouse but during millions of years they got bigger and bigger until they got as big as a Baluchithere (the biggest mammal which existed). After it mammals started to get smaller until now which the largest ones are elephant and giraffe and they still get smaller.

When the reptiles were separated from the amphibian they had very small species. During many years they got bigger and bigger and they got as big as a dinosaur. When they got to their largest size, they started to get smaller. During millions of years they got smaller and smaller, until now which the largest one is crocodile.

Amphibian had the same process.

All the animals and plants had the same process.

Is there any logical answer to this question according to your view?

Based on your view:  ( ? )

Based on your view: If you want to find a logical answer you can refer to my view in my book.

http://www.geocities.com/ramin1102000/bookpage.html

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Question 9: Why the small mammals, despite having an impressive circulatory system, have a small body size?  A mouse and elephant have a similar circulatory system because both of them are mammals, but their body size is different. Why?

Based on your view:  ( ? )

Based on your view: If you want to find a logical answer you can refer to my view in my book.

http://www.geocities.com/ramin1102000/bookpage.html

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Sincerely 

Ramin

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Dear Ramin, I have to go away for an operation on my leg this week, so I
will return to our correspondence when I am back - hopefully mid August.
Best wishes, Simon M

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Dear Dr Simon

I wish you health.

Sincerely, Ramin 

 Ramin Amir Mardfar