Paper 3

Plants, other  witnesses for the increases of gravity

Ramin Amir mardfar

(1995)

 We knew that, the size of animal species in every class has become smaller from past up today, and we justified this phenomenon with theory of the increase of gravity. We know the other than animals; other creatures are living plant's range, on the earth.
If the assumptions about increase of gravity, are true, we most observe its effects on from past up to day. In order to transfer the water and other necessary materials, plants have a system to transfer these materials, which is a like the blood system of animals. In plant's bodies, the root, which is like the heart of heart of animals, takes the water and other materials upwards, vascular system which are like blood vessels in animals, lead the water and materials to upper organs of plants. As we saw in animals, the evolution of transferring system in plants is not at the same degree. Among the plants there are primitive and evoluted classes. There is a question that; is the direct relationship between the strength of transferring system and the size of body, true in plants too? To answer the question, it is better to classify the degree of the evolution of transferring system of today's plant classes.
The group of angiosperms has the most advanced transferring system. Then there are gymnosperms which have more advanced transferring system. Then ferns have relatively strong root and vascular system. The group of horsetails has weak and primary roots and vascular system, then there are lycopodiales, which have the most primary roots and vascular system, and at the end there are bryophyta which almost lack this system.
Now, let's compare the size of body between these groups. The largest living plant on the earth is Giant sequoia, which belongs to angiosperms (the most strong transferring system.)
All plants which we see as tall trees in forests and other parts of earth, belong to the groups of angiosperms and gymnosperms that is they have strong transferring system! Ferns are next group, which have large sizes. Horsetails are able only to reach to 1 meter and lycopodials are smaller than they are, and at the end there are bryophyta, which grow crawling on the earth, or on other plants. So, we see that the direct relationship between the strength of transferring system and the size of body is true about the plants. This is a normal situation, because, it needs to overcome the gravity to transfer the water and materials to high parts and leaves of plants, and it is clear that, the stranger the pump system and leading system, the more the distance of transmission, so the plant will be able to transfer the water and materials to high parts, and if this system week, the plant had to shorten is height 

Living land plants	Structure of fluid circulation system	Body size
Bryophyta (Moss)	Almost lack fluid circulation system	Very small
Lycophyta (Club moss)	Most primary roots and vascular system	small
Sphenophyta (Horsetails)	Weak and primary roots and vascular system	smallish
Ptreophya (Ferns)	Relatively strong root and vascular system	largish
Gymnosperms	Advanced fluid circulation system	Large
Angiosperms	Most Advanced fluid circulation system	Gigantic

 
Could the plants, which have more primary transferring system and small sizes, larger their sizes in the past? If the answer is <<yes>>, we can hope that our assumption is true. So we study about the fossils of pervious plants. The remaining traces on the cools of carbonifer period (330 millions years ago), draws the scientific' attention. There are the traces of giant Lepidodendrals and giant kalamitals, the heights of some Lepidodendrals reach to 34.2m and the diameter of them reached to 1.8m, and the height of giant horsetails reached to 15m or more. And we also observe the traces of tree and tall ferns in these fossils. So it is clear that the answer of the question is <<yes>>, that is the pervious plants with weak transferring system, were able to larger their sizes, but they can't do this now, because the gravity was less than today, and they were able to overcome it. So the plants are other witnesses of gravity from past up to day.


  Paper 4

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