Evolution....and opinion of biologist.....

Hello guys! Today am here to aware you about the history of man and how we are created and different thoughts of scientist which makes us so curious.Actually i have lot of interest in all so i want to aware you about research which is done by me i hope you will really surprise when you read .... Different scientists have different idealogy so lets start....

Introduction:

First of all we must know what is evolution???

Evolution is a change over time;organic or biological evolution is series of changes in the genetic composition of a population over time.

Concept of special creation and organic evolution:

Two schools of thoughts emerged in the early 19th century in order to explain in cause of diversity of life and interpretationship among the living beings.

1:creation believed in the concept of special creation whereas

2:Evolution believed in the concept of organic evolution.

Linnelaeus Theory:

Carolus linnaeus (1707-1778) believe in divine creation.The concept of special creation is that all the living beings specifically created by nature in their present form it means that no change have occurred in them since they came into existence.

Organic evolution:

Aristotle was first believer of this concept it means that living beings gradually change whereby one may give rise to another and all the existing organisms are modified descendants of pre-existing ones The ancestors are simpler in their organization while the descendants are more complex.

Inheritance of acquired characteristics.

Lamarckism.

A French biologist,Jean Baptists Lamarck 1744-1829 WAS in charge of invertibrate collection at the natural history Museum in paris.He presents and published his history about evolution in 1809 is named as "Lamarcks theory of inheritance of acquired characteristics".

Lamarck can can be explains uses and disuse of organs ii. Inheritance of character......Lamarck argued that every organism is adjusted to its environment whenever the environment changes the organism entails need in order to satisfy these need some of the organs are put to greater use and other to lesser use or no use...consequently the organs which are uses the most become larger and stronger while the other are reduced in size......Lamarck quoted the examples of Blacksmith developing a bigger biceps in the arm that works with hammer.....Giraffe stretching its neck and forelegs to new length to reach to the leaves of the trees.........According to Lamarck the character which are acquired through use or disuse are inherited e.g,the long neck and forelegs of giraffe.The process continues until after many generations the organism is so changes that it become a new species it means that environment can directly change the species.

Objection:

However,we know that the acquired characteristics cannot be inherited because these do not affect the DNA of reproduction/germ cells.

Darwins Theory of natural selection:

Charles Darwins 1809-1882

An English biologist,charles Darwin published his theory of evolution called as "Theory of natural selection" in 1859,in the form of a book entitled "on the origins of species by means of Natural selection".

Darwins made a voyage around the south American coast and the island of the pacific from 1831-1836.He sailed along with other scientists in a ship names BEAGLE.

on south American coast Darwins observed and collected thousands of specimens of Fauna and flora.He made two important observation:

1:The fauna and flora of south American continent were apparently different from that of Europe.

2:South American fossils found by Darwin's through apperntly different from its modem species yet basically resembles them.

Fauna of Galapagos land:

When the ship reached Galapagos island Darwins found that most of animals species of those island live no where in the world.However,they resemble the species living on the south American mainland....the sort of situation indicated that the living animals of the island might have come from the mainland & then diversified on different islands.Darwins collected 13 types of finches although quite similar,seemed to be different species....some species were restricted to individuals islands....while others were distributed on two or more nearby islands

After his return to England in 1836,Darwins perceived as below:

The origin of new species and adaptation are closely related process e.g armored armadillo in American.

A new species would arise from an ansetral form by the gradual accumulation of adaptation to different environment from geographical.

After many generations the two population would become so different to be designed as separate species.This would have happened to the Galapagos finches.