5
   

Why did giant insects become small?

 
 
roger
 
  1  
Reply Thu 26 Feb, 2009 09:56 pm
@rosborne979,
Just a quibble, rosborne, but while smokeless gunpowder doesn't explode, it burns fast enough to fool most of us. Not addressing what happened with lightning in a high oxygen environment, you know. Just making the observation.
0 Replies
 
farmerman
 
  1  
Reply Fri 27 Feb, 2009 04:52 am
Thought this thread went the way of the mam moth. Evidence Ive seen re: post Permian involves occupation of the oxygen sites by iron banded formations and redbeds. The lightning in an O2 environment seems to need some "fleshing out". COurse, Im not staying current with my literature of late , but Im only guessing that, since lightning is a common ccurence and Ozone can be generated in excess by lightning striking and converting atmospheric Nitrogen into ozone, Im not so sure that there would be a depletion in the upper atmosphere.

So far the oxdiation of sulfur and iron by normal means along with the increased vulcanism of the post Permian can answer much of the "Big bug" anomaly.
0 Replies
 
Ramin mardfar
 
  1  
Reply Tue 15 Jun, 2010 03:44 pm
This is because:
Earth's surface gravity has increased.
Edit [Moderator]: Link removed

Ramin Amir Mardfar
[email protected]
.....................................
A new theory about: Why insects have small bulks?
Before explanation of my new theory, I point out to those theories which have been presented before on this respect.
Exoskeleton theory:
Insects have exoskeleton and this theory point out that this skeleton isn't able to grow more actually, the insect is imprisoned inside this skeleton and isn't able to get larger. Defects of this theory: All of arthropod owns exoskeleton, and some of them like crabs are able to own rather large body which is discordant with this theory. On the contrary, there are some insects that own softer exoskeleton, but again aren't able to enlarge. Also in the past (250 million years ago), there were insects that owned big bodies (like dragonfly by length of 75 cm) and this theory can't explain the reason of their existence. Because they owned hard exoskeleton too but they were able to enlarger!
Respiratory system theory:
Insects respiratory system comprise thin and capillary tubes called tracheae that supplies oxygen directly through existent pores on the body, to all insect bodies interior cells. That means, opposite other animals, oxygen isn't been carried by blood. It flows through inside of tracheas by means of propagation phenomenon, and reaches cells. This theory says that the propagation of oxygen inside the cells, is possible only in short intervals and if insects have large body, the length of tracheas will lengthen and oxygen can not reach cells. So insects are forced to own small body. About existence of large insects in the past, this theory predicts the existence of high percentage oxygen in earth's atmosphere. According to this theory, atmosphere's oxygen amount, 250 million years ago, was higher than the oxygen, would make it possible the propagation of it through the long tracheas of insects. Therefore insects at that time were able to be longer than present insects.
Defects of this theory:
250 million years ago, there were plants from the class of Horsetails and Club moss as the shape of very big trees. But today, the same plants exist only in very small size of some centimeters. Botanists believe that high consistency of atmosphere's carbon de oxide (CO2) is the reason of existence of giant Horsetails and Club moss at that time. You consider that entomologists predict a high consistency of oxygen and botanists predict a high consistency of CO2 for 250 million years ago. These two have confliction with each other.
This was a brief of theories existing in this respect. My new theory, in this respect:
Blood circulation system theory:
My theory is based on animals' blood circulation system. The theory compares the power and evolution of blood circulation system for animals and expresses the relation between bulk largeness and power of blood circulation system. According to this theory as much as blood circulation system is stronger and complete, animals' bulk can be larger (bigger). Insect's blood circulation system is too incomplete and there are no blood vessels. Insect's bodies, with lack of blood vessels, aren't able to supply blood consisting nutrition to remote cells, so their body are forced to be small. In this theory air pressure and gravity, are two physical factors that have impact on function of blood circulation system. The most effort of blood circulation system is used to conquest on gravity. As much blood circulation system is strong, is more able to conquest on gravity and send blood upper into animals' brain. Consequently, animal is able to enlarge more and taller. For example, elephants and giraffes, who own the most evoluted and strongest blood circulation system, are the largest and tallest ones among the animals.
For possibility of existence of insects whit big bodies and other big animals like dinosaurs and mammals in the past, this theory predicts a light gravity at that time. According to this theory, the amount of gravity in the past have been less than the present time, so blood circulatory system of animals was able to conquest better on it and enlarge animals body but along the time, gravity has been increasing and animals are forced to make smaller their body sizes.
As you know, there are some theories such as strike of meteorites or activity of volcanoes for extinction of dinosaurs, which each one has a lot of defects. It has been said ice ages for extinction of mammoths and a lot other theories for other extinctions. My new theory is able to answer all of these questions as a case of a theory and no need to state a different theory for each of these matters. This is my theory's name: "The relation between gravity and evolution" This theory is able to answer many questions about animals and plants and their extinction, which haven't been answered yet.
This theory is organized as cast of several articles that the sun of these articles now available as a book. The title of this book is "The theory of gravity increase". It's ISBN is 8-04-7061-964 in 1999 and have 120 page.
Ramin Amir Mardfar

Edit [Moderator]: Link removed
......................................................

Increasing Gravity and Animal Evolution


1. Why are insects so small?
The creatures of the Earth have different sizes. All of vertebrata, mollusk, worms, insects, belong to the animal kingdom. But we see that their individual kinds show extreme variations in size. The largest animals, such as whales and giraffes belong to the class of Mammalia, and the smallest ones, i.e. insects and Acarina belong to Arthropoda. Largeness and smallness are relative qualities. A thing, on its own, cannot be large or small, and only by comparison with other things, becomes large or small. If we only observed the insects of the world, we couldn't tell that they are small creatures, but when we see a fly resting beside a horse, we become surprised at the great difference of their size, and the question occurs to us: Why are insects smaller than other creatures?
"Because of the limited weight of hard exoskeleton, the size of no arthropoda creature encroaches a determined extent." This has been the answer of zoologists and entomologists to the above question. But the answer isn't satisfying even for themselves. Because the body of many insects is soft, but they yet are very small, and against those are crayfishes whose exoskeleton is very hard, yet are greatly larger than insects! Entomologists compare the body structure of an insect with that of a large animal such as a giraffe. They are searching for factor in bodies of insect, which prevent their getting big. But till now they have had little success. For finding an appropriate answer we must look in another direction. In other words, we must instead of searching for the preventive factor of growth of insect, search within the system in the body of the giraffe, which the insects lack, and which contributes to greater size of the body.
The head, which carries the brain, is the most important part of any creature's body. The brain is important and sensitive, and must receive enough water and food all the time. Providing necessary water and materials to the brain is among the primary responsibilities of circulatory system. The heart, like a pump, turns the blood, which carries water, and nutritive substances and the vessels carry the blood to the brain, by use of other organs, which act like tubes.
Suppose we want to send water from a tank, which is placed on the lower part of a structure to upper floors for usage of resident of the structure. But if we do not use tubes (plumbing) and simply tried to carry on the job only with a pump, it would be a difficult task. The pump can not carry the water to regarded points of the upper floors without tubes and plumbing, and only to a limited extent can the pump shoot it upwards. In this case, the water not only won't reach to desired points of upper floors of the structure, but also at the lower floors, instead of arriving at its desired points (bath and kitchen) it will flood into all the rooms and walls. Without plumbing tubes, we couldn't make high structures functional, and we would be convinced to construct low ones in order to distribute the water for its residents.
Within the body of the giraffe, there is not only a strong pump (heart), but also many "plumbing" tubes (arteries, veins, capillaries), so its body can convey blood to the highest points where the brain is located, and to other organs and systems, easily as well. Any organ of the body of a giraffe can receive as much blood as it needs. When the animal eats food, the blood is succinctly guided to its digestive system, operates as the feeding organ. Any cell of the body of the giraffe can receive necessary amounts of water and other substances from nearest capillary systems and send redundant and unnecessary substances to be discarded, through the same system.
But the body structure of an insect possesses an entirely different system. There is no "plumbing" to distribute the "water", but only a pump (heart), which carries the blood from the dorsal and pushes it forward. There isn't any upper floor in this structure, and at the lower rooms, the water, instead of flowing in tubes, fills all the rooms, and the residents are basically flooded in water. Individuals in the lower floors of an insect, not only receive food from the "water", but also pour the unnecessary substances into it. The insects have an open circulatory system. This means that there are no vessels or "plumbing" within their body, and the blood moves openly through it. There, every place is full of blood, and organs and systems of the body are "drowning" in it. They receive water and necessary substances from it, and pour the unnecessary excrament into it. The heart, for the lack of vessels, cannot convey the blood to far distances and high points, so all the systems of the body have to gather around the heart, so as not to suffer the shortage of water and necessary substances.
The circulatory systems of insects have little authority on the rate of distributing the blood to different organs, and organs which are near the heart, receive more necessary materials and enjoy preferable conditions. The brain, being the most important, is located in front of the aorta, where the blood first emerges from the heart. The heart always takes the blood from the back of the body and pushes it forward towards the head. If the brain of insect was at a high point, like the giraffe's brain, the heart couldn't send blood to it for lack of vessels, so the brain and other organs of insect have to be near the heart. In other words, the size of the insect must be small.
In this manner, it is obvious that any creature wanting to grow in size, must have the necessities of distributing the blood, and because the insects lack such means, they cannot grow in size. In other words, the insects, by lacking the "plumbing" vessels, have small sizes, and the giraffes having so many vessels can then become comparatively large. On the whole it can be said that any creature which has a more complete circulatory system, will become larger than others.
To help make the matter more clear, it is noteworthy to compare the circulatory system and size of some other creatures also. There are species in the worm groups which, on the whole, lack the circulatory system and are very small and microscopic, i.e. Nematoda and Bryozoa. Some of worms have a simple circulatory system consisting of some linear vessels and a small heart. These species can make themselves a little larger, such as Phoronidea, Sipunculoidea and Brachiopoda. Among the worms, only the segmented ones have an advanced circulatory system, consisting of linear and partial vessels, some hearts and capillaries. Their blood circulation is closed. The segmented worms, having such a circulatory system are the largest species among worms, i. e. Rhinodrilus Fafneri which reaches 210cm long and 2.5cm diameter, and Eunice Gigantea which is 3m, long. In the Mollusca group, we see a variety of circulatory systems, both open and closed. The individuals belonging to open circulatory system, and having few vessels and a simple heart, such as Amphineura and Gastropoda are smaller. But individuals whose circulatory system is more advanced, such as Bivalves, are of a larger size. Finally, Cephalopoda, who are the most developed ones of Mollusca, and have a closed circulatory system with many vessels and heart chambers, are larger than other Molluscas, such as large Octopuses and Architeuthis, which have a body of 2.5m long and arms as longs 12-18m.
All members of the Arthropods group have an open circulatory system, so they can not grow very much. The extent of the evolutionary process, however, is not the same among all individuals of this group. Among the arthropods, Crayfishes are the largest species, because their circulatory system, in addition to their hear,t has many arteries and the heart can guide the blood to relatively far distances within them. But because of lacking capillaries and veins, the blood is distributed in its coelum "body cavity". Also, the circulatory system is open. The Circulatory system of Scorpions and some other Arthropods has fewer arteries, so they are smaller than Crayfishes.
All insects lack vessels, and only have a Vaisseau Dorsal, which consists of some ventriculites and end in a short aorta. So insects must remain a small relative size. Among insects, those which have longer Vaisseau Dorsal, such as Cockroaches and Grasshopers are larger than ones whose Vaisseau Dorsal is shorter, having less ventriculites, i.e. Coccidaes.
The size of the smallest insects is less than the greatest Monocells, i.e. 0.25mm. But these insects are not the smallest Arthropods. Acarina are the smallest ones. Parasite Vegetable Acarias are even smaller that 0.1mm. For observing Acarias of Eryophidae group, magnifying instruments are needed and used. So these small Acarias must have some simpler circulatory system than even insects. Larger Acarias, like insects, have a Vassea Dorsal and heart. But small Acaria lack such organs and their circulation is made only by body muscles and movements of internal organs such as the digestive system.
Among Vertebrata, the ones who have a more complete circulatory system, are the larger creatures, i.e. Mammalia, whose circulatory system is the most complex and complete, so they become the larger species such as the whale, elephant and giraffe. So as a whole we conclude that any creature living on earth, establishes a direct relationship between its circulatory system and its relative size. No creature on Earth is an exception to this principle.
2. Does the force of gravity increase?
As we know, there is a direct relationship between the power of a circulatory (blood) system of an animal and its size. In animals, the heart tends to push the blood towards the top of the body where the head is located while gravity force pulls the blood down and tries to prevent it from rising. Thus the heart must overcome the force of gravity in order to push the blood towards the top of the body. The more it is successful, the more the blood rises and the height of the animal is allowed to increase.
Mammals are the largest animals because they have the most developed circulatory system and, more than other animals, their 4-chambered heart can overcome the force of gravity and send the blood upwards towards the head where the brain is located. For this reason, mammals have the longest necks and legs. After mammals, birds have the most developed circulatory system. Their heart is also 4-chambered and, to a large extent, it can overcome the force of gravity and also send the blood upwards towards the top of the body, where the head of an ostrich, for example, and other tall birds is located. This is the reason why the birds' necks and legs are also rather long. The blood circulation system, both in mammals and birds, are perfectly segragated and the bright blood is separated from the dark.
The reptiles are in the class lower than mammals and birds. Their circulatory system is imperfect and their dark blood is mixed together with the bright one, because their heart is 3-chambered. The 3-chambered heart can send blood forward and this is the reason why reptiles can not hold their head upward, and have to creep on the ground in the lying positio,n and have shorter legs, and we call this action creeping, and the animals are called reptiles. So we observe that because of lack of a strong heart, they have to creep on the ground, for their heart cannot transmit much more blood from the body and send it upwards. However, reptiles' heart, contrary to amphibian's, is much more effective because they have an incomplete wall between their ventricle, although it cannot send the blood upwards, at least it can make it move forward horizontally, and because of this, the reptile's body, such as Lizards, Crocodiles and Snakes, grow horizontally.
This is not the case for the amphibians and their body, which is smaller, both horizontally and vertically. Although the fishes' hearts are 2-chambered, they can grow horizontally because they have a perfect circulation system, not mixing their dark blood with the bright one, and being aquatic, because horizontal movement of blood does not need to overcome gravity and their heart is able do this. Understanding the relationship of the strength of the heart and the body size and design of animals is easier when we study, in depth, the living animals we have on the earth today.
But in the past, there were animals on the Earth, as well as the present animals, which do not exist today, and we discover them by their fossil traces. Such as with today's animals, was there any relationship between the strength of blood circulation system of animals in the past and the size of their body?
Dinosaurs are the primary animals of the past that one might consider, because their huge body is intriguing and holds an interest for everyone. The dinosaurs belonged to the reptile class and had a 3-chambered heart. Thus, the old reptiles, with a 3-chambered heart, and an incomplete blood circulation system, could grow so large and hold their heads upward, and have long necks and legs. Where as today's reptiles cannot even raise their head even slightly, and have very short legs, or do not have any legs at all, and must creep upon the ground completely. Isn't this strange?
Isn't the relation of strength of the heart and the size and design of an animal's body also supposed to be true for the dinosaurs? It's thus perhaps better to study about other old animals and compare them, in terms of strength of the heart and body size, in that period, to find the reason why dinosaurs, having an incomplete circulatory system, could grow so large. If we study more carefully, different animal species in the past, we can perhaps arrive at the following results:
1. Observing this phenomenon, from past to the present, the body size of all animals has been gradually decreased. In the Mollusks class, there was an animal 4.5m in diameter called Endocras, which their equals today are only a few centimeters in thickness. In the insect class, there were dragonfiles (Meganeuropsis) 71cm long, which their equals today are much less than 15cm. In the amphibian class there was an animal called Eogyrinus, 4.5m long, but today's amphibians are not more than few centimeters. In the reptile class, Brontotosarus and Tyrannosaurus existed in the past but now alligators and other Crocodiles are the largest reptiles. From the mammals in the past, the Mammoth, Mastodon, and the largest mammals, that is, Baluchithere and also the Giant camel existed - but today they do not.
2. In each period of time, there has been the direct relationship between the strength of the heart and the size of the body. In the past 500 million years, Endocras was larger than all other animals because its heart was stronger than all of them and the blood circulation system was more developed than were the others. In the past 330 million years, when the amphibian Eogyrinus (with 4.5m long) and Erypos with 2.5m long existed in the Carbonipher period, they were larger than all the animals living on the land, because they had the strongest heart of all the animals at that time. Then in the past 200 million years, reptiles became the largest, because they had the strongest heart at the time. Mammals like Baluchithere and Mammoths became the largest land animals on earth in the past 20 million years, because at that time they also had the strongest heart. Nowadays, mammals such as elephants and Giraffes have the largest bodies among land animals because they have have the strongest heart of all the animals today.
3. The third observation is that as we close to the present time, from past to today, animals need stronger hearts to create larger bodies. In the Carbonipher period, the heart of an amphibian could allow an animal to reach 4.5m long, but the same heart today only allows an animal to become a few centimeters high. In the past 200 million years, a 3-chambered heart of a reptile could create a dinosaur, but now it can only create animals as large as Snakes and Lizards. In the past 20 million years, a 4-chambered heart of a mammal could allow for a Baluchithere and other large mammals, but today the same heart can only create animals as large as elephants and giraffes. (Although the Whale is larger than the elephant and giraffe, but this characteristic is because of it being aquatic and because its body grows in a horizontal state, and if tge whale lived on land like the elephant and tried to raise its body vertically and stand, it wouldn't be larger than the elephant and giraffe.) In the past 250 million years, the blood circulation system in insects, could create dragonfiles 71cm long, but now it can only allow for 15cm ones.
So far, we know that the heart needs to overcome the gravity force of the Earth in order to send blood upwards to the heads of animals. We observe that any animal with strong heart can overcome this force better and this contributes to make the animal higher and taller. But how is it possible that an animal with specific heart contraints at one time, can overcome the gravity and become larger while in at a later time, the same specific heart constraints cause the animals to have a smaller body?
Only in one case this is possible and that is if we suppose the strength of gravity at these two times is different. We can thus justify why it is in the past that an animal with an identical heart to today's animals is larger than its modern counterpart. Such as it is, that the large animals did not extinct suddenly, but rather gradually, so it must be that the increase of gravity from past to present has also occurred gradually.
When a Molluscan Endocras, that had an open blood circulation system, in the past 500 million years, could reach 4.5m in diameter, and move its large shell and keep on living, certainly the gravity must has been lower in order to allow for such a result. From that time to the present, no shell has been created because the gravity has increased and this animal could not grow it in these conditions. In the past 330 million years, when an amphibian, 4.5m long, lexisted, its 3-chambered heart and incomplete blood circulation system could easily overcome the gravity and send its blood upwards to its head. Surely at that time, the force of gravity must have been lower than it is today. Since then, no amphibian has become so large because the gravity increased and the amphibian's heart could no longer overcome the force of gravity, which caused their bodies to become small.

We can thus cite a primary reason for the extinction of the dinosaurs, if we accept that gravity has increased from the past to the present. It is interesting that the dinosaurs themselves did not become extinct suddenly, and that their extinction has come about gradually, throughout millions years. An additional, most important issue is that their extinction began from the larger animals, because the gravity increased gradually, and prevented their blood from reaching their head, and as a result, the animals had to gradually decrease in height and body size.
In other words, the larger animals became extinct and the smaller ones survived, and only counterparts who are small and who creep on the ground were amongst the survivors. The animals in the mammal class have also lost many of their largest types, such as Mammoths, because of gravity increase. An interesting point is that presently, the larger types of this class are in danger of extinction; that is, the elephants and the rhinoceroses. From this we might conclude that the continuing increase in gravity persists and that it is bringing an end to the taller and larger animals. We may not be able to perceive this so clearly today, because this increase in gravity occurs very slowly, and its effects only become evident through much longer time spans, such as thousands and millions of years.

Ramin Amir mardfar

......................................
Introduction
1. Why the insects have so small sizes?
2. Dose the force of gravity increase?
3. Plants, other witnesses for the increase of gravity
4. Megatherium and the increase of gravity
5. How can the gravity increase?
6. Gravity variation from the equator to poles?
7. The sea animals and the increase of gravity
8. The relationship between the blood system and air pressure
9. The extinction of dinosaurs and the gravity increase
10. The circulatory system in zero gravity
11. Why did the previous mammals have small bodies?
12. Why the body size of the mammals are different?
13: Relationship between Pressure & Growth speed
14: If the Earth Expanded, where did all the extra mass come from?
15: A physical question
16: New Hearts in the future
17: Axolotl
18: The new class of animals
19: Why the body of Coelacanth grow several time?
20: The relation between blood circulation system and animals body size
21: Were dinosaurs warm-blooded or cold-blooded?
22: The method of finding gravity in the past time
23: The graph of land animals' size during the tim
24: Pterodactyl
25: Big Bang or Steady-state universe
26: Are the cells, the establishing unit of our body?
27: Ramin Mardfar & Dr. Simon Maddrell (July 2008)
28: How can a sheep be grown as large as a cow?
29: Ramin Mardfar & Prof.Dr.Dominique Adriaens
talk72000
 
  1  
Reply Tue 15 Jun, 2010 03:52 pm
Also the Oxygen level went down as CO2 increased. The high O2 level helped insects to grow.
0 Replies
 
rosborne979
 
  2  
Reply Tue 15 Jun, 2010 03:54 pm
@Ramin mardfar,
Ramin mardfar wrote:

This is because:
Earth's surface gravity has increased.

No it's not. Earth's gravity hasn't increased enough to make any difference to insect body size. The primary reason insects have changed size is that the composition of the atmosphere has changed (less oxygen) which affects their respiratory system.

0 Replies
 
edgarblythe
 
  1  
Reply Tue 15 Jun, 2010 04:02 pm
It's because the dinosaurs stomped on the big ones and crushed them all. The small ones hid.
rosborne979
 
  1  
Reply Tue 15 Jun, 2010 04:05 pm
@edgarblythe,
edgarblythe wrote:

It's because the dinosaurs stomped on the big ones and crushed them all. The small ones hid.

Survival of the scaredest? Smile
0 Replies
 
edgarblythe
 
  1  
Reply Tue 15 Jun, 2010 04:07 pm
I know I would be hiding and never come out until the great asteroid hit.
0 Replies
 
farmerman
 
  1  
Reply Tue 15 Jun, 2010 07:11 pm
@Ramin mardfar,
Theres a lot of work that went into your post . However, I wonder where you and your advisor were getting your data that has any smallbit of data regarding HOW we should measure Paleogravity? Many people have worked on this and , as far as Im concerened we have almost yearly "new" methods to determine gravity in the geologic past and most of these are not only unreliable but non repeatable in section. Tang et al have developed a computational method for paleogravity in 2008 that uses core sections of IGNEOUS material and by mesuring the density of a given core section (One must make sure that this section is perpendicular to the placement of the igneous body). By using density and measuring the elastic deformation modulus (estimations from mineral laminae in feldspars and biotite micas). The formulae for calculating the section of rock must be compared to another method by SHeridan et al where they mesured inclusion temperatures of zircon and /or forsterite/fayalite ratios and developed a "lineament" gravity section for the igneous laminae. These two methods are only lately being taken seriously enough to develop actual field tables. AND, one other thing, THESE methods are only valid for igneous emplacements. The rocks in which the "big bugs" are fossilized are all sedimentary.

Rather than go much further on this approach, why not look at the data that the USGS and several papers in the Geological SOciety of AMerica Bulletin have presented. That is, big fossil bugs of specific ages correlate quite nicely with data that shows that oxygen levels were very high in specific areas of the planet. Since you know that insects are not very efficient in their respiration, their size limitations today can be experimentally established by oxygen as a limiting edaphic factor. I see no reason why that should NOT have pertained in the Carboniferous as well.
rosborne979
 
  1  
Reply Tue 15 Jun, 2010 07:15 pm
@farmerman,
He's trying to sell his book, the link to which, the moderator removed. The text he posted is mostly a cut/paste from said book.
farmerman
 
  1  
Reply Tue 15 Jun, 2010 07:43 pm
@farmerman,
I googled you and found that youve been working on this "theory" for some time. Do you have any knowledge of geophysics? Im kind of concerned that you are running full steam and may be missing some basics here.

You seem to want to apply large sizes to something relataed to gravity anomalies. When you looked at megafauna, you certainly must look carefully at the fossil record because megafauna have been showing different bulks for different areas on the planet. For example, the MegaAVIES of the Eocene through the Pliocene were mostly an evolutionary function of the breakup as South Americas portion of Gondawana split off from Africa at the Parana sutures and then 4mya it re- joined N AMerica by the collisions of the North AMerica and NAzca plates. The BIG birds that roamed all over the South American continent were different than the biords in most of the rest of the world. THese were really big mothers who could eat a whole pig for lunch. When the S and N American plates rejoined, these big meat eating flightless birds were no longer the top of the food chain and were gone shortly after the N AMerican Megafauna roamed south and lunched on these big birds. I dont think that gravity anomalies had anything to do with the megabirds . We can see, if we look carefully at stratigraphy, we can see that megafauna were living in one part of the world and their relatives (who werent so "mega") didnt attain large sizes in other areas.

How bout the mini mammoths of Catalina island or Wrangle land?
If you continue on your path , I think you had better obtain some compelling evidence before you try to publish.

In the case of insects of the Carboniferous, these things were worldwide and several other species like eurypterids and Limulae both of which could have been facultative air breathers , were also growing to large sizes
0 Replies
 
farmerman
 
  1  
Reply Tue 15 Jun, 2010 07:49 pm
@rosborne979,
Well, maybe this theory will go over with the "Coast to Coast" crowd.'I wouldnt try to give a talk to a bunch of geophysicists, they are a humorless lot.

PS, if that clip was from a book, then Id like to send Roberta a PM, her services are desperately needed. We have a full frontal editing emergency
rosborne979
 
  1  
Reply Tue 15 Jun, 2010 08:11 pm
@farmerman,
farmerman wrote:
PS, if that clip was from a book, then Id like to send Roberta a PM, her services are desperately needed. We have a full frontal editing emergency

Unfortunately, fixing the editing isn't going to fix the basic content.

Trying to derive gravitational changes based on heart rates and body size of various fauna seems like a fundamentally flawed premise to me.
0 Replies
 
talk72000
 
  1  
Reply Wed 16 Jun, 2010 03:41 pm
The earth is bombarded daily with meteorites so it accumulates a lot of material over the years. I had thought of the gravititational constant and roughly calculated that a quarter of the earth had to disappear to get a lower g value. A rough guestimate that the earth gains a ton a year and over 65 million years wouldn't amount to that much . It would probably add a huge mountain or even a range of mountains but not a quarter of the earth.
0 Replies
 
farmerman
 
  1  
Reply Wed 16 Jun, 2010 05:18 pm
@Ramin mardfar,
Quote:
As much blood circulation system is strong, is more able to conquest on gravity and send blood upper into animals' brain. Consequently, animal is able to enlarge more and taller. For example, elephants and giraffes, who own the most evoluted and strongest blood circulation system, are the largest and tallest ones among the animals
This sounds like BillRM.
vince33x
 
  1  
Reply Sat 3 Jul, 2010 11:33 pm
I believe insects and other arthropods no longer attain the size they grew to in the Carboniferous era is due to the lack of oxygen content in the atmosphere. Today, the oxygen content is lower than it was during the Carboniferous. Aren't you glad!?
0 Replies
 
roger
 
  1  
Reply Sat 3 Jul, 2010 11:54 pm
@farmerman,
Rama Fuchs
0 Replies
 
 

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