Paper 11

Why did the initial mammals have small bodies?

Ramin Amir mardfar

(1995)

  Why did the initial mammals have small bodies?

The first mammals which appeared on earth had the body size of today's small mice. Then by the passage of time their bodies become larger. The well-know example is the species of horse which had small bodies at the time of their emergence, and than they became larger. The horses began from Eohippus which had 28cm in height. Then they gradually became larger and produced Mesohippus, Merychippus, and finally today's horses. The first camels also were very small and were 50cm height, then their bodies became larger (Oxydactylus) and then they converted to Gigantecamelus fricki which had 4m height. After this extremity they began to become smaller until they reached to the height of today's camels which have 2.3m height. the elephants also developed from previous small animals. At first, the elephants were small and they had no trunk and they had rather big front teeth. Then they became larger and larger until they converted to Mammoth and Elephas imperator with 4.1m height. After this extremity they began to become smaller, too. They became a little smaller (Matodon) and finally they reached to the size of today's elephants, that is, with 2m height. Rhinoceroses also developed from previous small animals, and then they gradually became, larger, until they produced larger species of Baluchithere. Baluchithere has been the largest mammal on the earth up to now. But later they made their bodies smaller, too, until they reached to the size of today's hinoceroses. Deers, like other animals began from small bodies and then reached to the size of Civatherium which was to times bigger than buffalo than its head was as large as elephant's head with a pair of antler on it. They gradually became smaller until they reached to the size of today's deer's. Carnivorous animals also began from small bodies then they became larger until they reach to their extremity, like Maicrodous was similar to tiger but very larger than it, with fangs which were 14cm in length. After this they became smaller and reached to the size of today's carnivorous animals. These examples do not include the mammals only, if we have a look to the genealogy of any animals, we can see that it begins from a small animal and then it gets larger and reaches to its extremity and then, it begins to get smaller again, until it reaches to its current size. The class of reptiles do not need to be explained and all of us are aware of their emergence of first small reptiles from amphibians and their getting larger to dinosaurs and then their gradual getting smaller up to now. The class of birds also began from small bodies. Archaeopteryx, the first bird, which was as small as a pigeon, developed from reptiles. Then they became larger and larger until they produced species as large as Moa (Dinornis maximus) with 4m height and elephant, like bird (Aepyornis maximus) with 3.5m height and 500kg weight, they were living up to several hundred years ago, the first one in New Zealand and the second one in Madagascar. But these birds also made their bodies smaller until they reached to the size of today's ostriches, which had only 2.6m height and 137kg weight. Previously, we knew that by the passage of time, the gravity increases gradually from past up to now, and this causes large animals make their bodies smaller, because of not having enough strength to transmit the blood to high heights in high gravity. When these animals completed their blood circulatory system, they could get their lost strength again and they were able to overcome the high gravity and made their body larger. Large amphibians like Eogyrinuses which had 4.5m height, made their body smaller, because of the increase of gravity. Later some of these shrunken amphibians could complete their circulatory system and became able to complete their circulatory system and convert to first reptiles. These first small reptiles were able to overcome the increase gravity of that days and made their bodies larger by the help of their strong circulatory system, so that they were able to produce such giant dinosaurs. But the increase of gravity continued without interruption and it increased inasmuch as their circulatory system had not enough strength to overcome gravity and they had to make their bodies smaller. Birds and mammals developed from small reptiles an by the help of their strong circulatory system they could make their bodies larger, but by the more increase of gravity again, they had to make their bodies smaller. Up to here, if we accept the increase of gravity, we don't have more problems. But, here there is a question, when mammals to be produced, there were large reptiles, why they did not evolve and why they did not produce the mammals, and why was this evolution among small reptiles. If the mammals were produced from large reptiles of that time, they did not have to make their bodies larger again and waste the time. Also this is true about birds, why the Archaeopteryx did not develop from a large reptile, and why did an small reptile convert to the first bird and why the birds had to waste more time to make their bodies larger, and also we can ask that why didn't the first reptiles develop from amphibians with 4.5m length and why did the emergence of reptiles begging from small amphibians? Suppose that there is an escalator which moves downwards and everything which is put on it is being taken down. Each step has 1cm height that is the first step is 1cm higher than earth, the second step is 2cm higher than earth, the third step is 3cm higher than earth etc. And beside the steps there is a wall on which the height of each step up to earth is written, that is, beside the tenth step number ten is written, which shows the height of 10cm. When the escalator moves downwards, the steps comes down but the numbers are fixed, that is when the tenth step comes down, it is settled in the place of the ninth step, and its height decries from 10cm to 9cm. Now, suppose that different animals stand on the steps of escalator, but in a certain order, in a way that, the number on the wall indicate the height of the animal which stands beside the wall. That is, the mouse with 4cm height stands on the forth step, the cat with 20cm height, stands on twentieth step the rhinoceros with 1m height on hundredth step and elephant with 2m height on two-hundredth step and also giraffe with 4m height on four-hundredth step and the rest of the animals like them. The downward motion of the escalator is like the increase of gravity, which tries to make the body of the animals smaller, draw them downwards and put their step beside the minor number. For example, the mammoth which stood on 4 to 5m step million years ago, has moved downwards gradually by the effect of the escalator's downward movement, and now the elephant which is from its offsprings stands on the step with 2m height. Moa (Dinornis maximus) which was standing on four- hundredth step hundreds of years ago, by the passage of time by the effect of the movement of the escalator came downwards and now the number of the wall, beside it shows the number of 260, that is the place of today's ostrich. The ancestors of tiger were on upper steps in the past, but gradually they were brought down by escalator, and now the tiger stands on lower steps, Gigantecamelus fricki stood on 400th step in the past, but now the escalator has brought it to 250 that is the place of today's camels with 2.5 heights. Each moment the escalator moves downwards, that is the gravity lead them to small bodies, but why the escalator which moves dawn wards for million years, couldn't bring all of the animals to the lower step, and after all this time, that the escalator move downwards, there are some animals which stand on higher steps? This is for the reason that, the animals are able to go up the steps. Although the escalator moves downwards, some of the animals jump from one step to higher step and by doing this, they can prevent their more going downwards, but this jumping doesn't all the time and at completely accidental times. This jumping is possible by gaining a stronger circulatory system, that is, any animal which gains stronger heart, has the permission of jumping to upper step, because it is in this case that it can overcome the gravity more, and make its body larger. An small reptile which stood on first steps 200 million years ago, by completion of its circulatory system and by converting to a mammal, it could be able to go up the steps and go up one by one till it reached to upper steps. That is, it generate Baluchitheres, Mammoth, larger camels, horses and other large mammals. We know that the evolution of the animals occurs by gene mutations and natural selection. The evolution of the circulatory system, too, follows this, and also we know that gene mutations occurs accidentally and out of thousands of mutations, one of them may be good for the animal and be selected to clarify this subject we return to escalator again. An animal is standing on a step and wants to gain the power to jump to the upper step. Suppose that, if the animal eats some spinach like <>, it can be strong and go to upper steps. But this spinach is in cans with closed door and the doors have a lock which is ciphered and its cipher consisted of three numbers and it can be found only by changing the numbers accidentally. Each animal wants to find the cipher of the lock very soon, open the door and eat the spinach, so that it can jump to upper steps unless, the escalator will draw it downwards. At the foot of the steps there is a deep pool and the animals don't want to fall into it and drown, so they should change the ciphered numbers very soon and find the cipher of the lock and open it. Some of the animals find the cipher and can go to upper steps, and at upper step, too, they don't stop their work and attempt to open the other lock, because the escalator don't stop its work and tries to pull them downwards. This competition between animals and the escalator continues. Or in other words, the competition between animals and the increase of gravity continues. But our question has not be answered yet, why finding the cipher always occurs between small animals? If finding the ciphered is accidental, so, the large and small animals should have the equal chance in finding it. But we see that is not so in proactive and small animals have move chance than large animals in finding the cipher and going up the steps, why? That is, if they had equal chance, both large and small reptiles, should be able to find the cipher of generating a stronger heart and convert to a mammal, but we see that, large reptiles couldn't do this and only small reptiles could discover the cipher and convert to mammal and could go up the steps. Here, we see that there is discrimination between the upper and lower steps of the escalator. Every animal which is on lower steps, have more chance to discover the cipher and opens the doors of the cans sooner than the animal which is on upper steps. Because the cipher of the cans is the same in all of the steps, this is justified by one procedure, and that is the number of participants which are in each group, that is the number of the animals in each species. Suppose that two animals of each kind are placed on each step, that is both of them begin to find the cipher of lock it is clear that, this group which has two members, has double chance to find the cipher of the lock. They find the cipher of the lock, sooner than the other one-member groups and find the cipher of the lock sooner that the other groups and go to upper steps. The group which has more members has more chance to find the ciphers very soon and go to upper steps. We consider the numbers of the cipher like the genes of the animals, their chance occurs by reproduction and each offspring represents a chance of number. In each reproduction the mutation occurs and the gene of the children has a little difference with their parent's gene. Out of thousands of offspring, only one of them has the cipher of opening the lock, that is, one of them has the gene of generating a strong circulatory system and only it is able to go to upper step, that is, the natural selection selects this gene which contains the correct cipher, if the number of the reproduction in one species is low, the number of the changed ciphers is less, but if a lot of animals reproduce together the number of the offspring is more and the chance that one of them carries the correct cipher is high. Now, let's have look to the nature, which animals have high ability of more reproduction and the number of which is high? Let's recall the mouse, that can bear several offspring in a short time and these offspring's became mature after a short time and can bear offspring's again. Let's recall a cat that can bear several offspring each time but only once a year. Then it takes one year until they become mature and begin reproduction. So the rate of reproduction of cat is less than the mouse, so it has less chance to find the ciphers of the locks. Sheep bears only one lamb in a year, and it takes one year until it became mature, so the chance of the sheep is less than the cat. Let's recall the elephant. The elephant bears an offspring, in several year and this offspring becomes mature after several year and then it bears an offspring and during the period that an elephant bears and offspring, the mouse reproduces hundreds of mice like itself and all of these offspring try to find the cipher of the lock together. The number of the mice became more and more and they change the cipher of the locks rapidly, that is, they generate new genes. It is clear that, the chance of appearing a desirable gene among the numbers offspring's is high and possibly one of the mice has the desirable gene and is able to go to upper step. During this time the elephant has tested only one cipher of the lock and it does this very slowly. The number of different genes which is generated by a population of mice in one year needs thousands of years to be generated by the elephants. Because the escalator don't differentiate in downing the steps and don't notice the hugeness of the elephant and pulls them down with equal speed. It is clear that the mice can compensate the downward movement by going up the steps, but the elephant goes down and have no haste to find the cipher of the lock and eat the spinach. Mammoths were 400th step 2-million year ago, but because of low reproduction they couldn't open the lock to eat the spinach and get stronger and also they couldn't go up the steps so they came down along with escalator and now their children, that are elephants, are on 200th steps. 200 million years ago the primitive mammals were very small with high strength of reproduction, they could find the ciphers rapidly and go up the steps and generate large mammals. Here there is an interesting thing, this system is automatic. In nature there is a converse relationship between the largeness of the body of the animal and the power of its reproduction, and all of us know that, the larger the animal, the more the period of its reproduction and its maturity and the number of offspring is, so the number of its population is less. Instead, the smaller the body, the shorter the period of reproduction is, as a result the population of these species is high. We can say that by decreasing the size of the body the speed of finding the cipher is high and by increasing the size of the body, the speed of finding the cipher is slow. Now, again consider the escalator, the escalator tries to draw animals downward, instead, the lower the animal comes, the speed of finding the cipher gets more and the animal goes up more, by going up, the speed of finding the cipher declines and the escalator can draw it downward. The increase of gravity draws bodies animals toward small sizes, instead the smaller the body of the animal gets, the more increase the speed of its reproduction, and it can generate different kinds of genotypes and discover the genotype a strong circulatory system and by doing this, it can overcome the gravity more and gets larger. By increasing the body size, the speed of reproduction lowers again and the animal yields to gravity, and this is repeated continuously. So we see that whatever the escalator works, it is not able to pull all the animals down the and although the gravity is increasing for million of years gradually, but instead the animals learn how to overcome it and make their bodies larger. So, the result is the beginning of the next evolved class, is from the animals of the previous small class. Therefore can we say that now is if the next class wants to be generated, the offspring of which today's species. So, the result is that, the commencement of the next more evolved class, is always from the small animals of the initial class. There can we say that now is if the next class wants to be generated, the offspring of which today's species will they be?

Paper 12

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