HUMAN EVOLUTION

1. HUMAN EVOLUTION PRESENTATION BY: RAHUL PATEL 09EC

2. EVOLUTION v/s CREATIONISM The Bible teaches that God created man Evolution begins with the assumption that man has evolved from ape-like creatures So God created man in his own image, in the image of God he created him; male and female Pick your relative

3. INTRODUCTION EVOLUTION = E (From) + Volvere = THE Act Of Unfolding Nothing in Biology makes sense except in the light of evolution. (Theodosius) Evolution is the doctrine according to which higher forms of life has gradually arisen out of lower. (Savage et al.) Evolution is the gradual descent with modification. (Charles Darwin) Evolution is the gradual orderly change from one condition to another. (Herbert Spences) Evolution is a discontinuous process rather than gradual one. (Hugo de Vries)

4. EVIDENCES OF EVOLUTION • Evidences from Fossils • Evidences from Biogeography • Evidences from anatomy and morphology • Evidences from embryology

5. EVIDENCES FROM FOSSILS Fossils are the dead remnants of dead plants and animals which were buried under the earth crust somewhere in the past. ARCHAEOPTERYX – Connecting Link between Birds and Reptiles EVOLUTION OF HORSE

6. Evidence from Bio-geography • Biogeography deals with the distribution of life on the surface of earth& also various factors controlling this distribution. • The flora & fauna we see in different bio-geo regions have descended from their predecessors which differs and have migrated from their place of origin to their newer areas but have failed to return to their place of origin. Therefore they got separated geologically

8. Evidence from Morphology & Anatomy • Homologous organs are those organs having similar appearance & different functions. • Analogous organs are those organs having different appearance and similar function. • Vestigial organs

9. HOMOLOGOUS STRUCTURES • ANALOGOUS STRUCTURES

10. Vestigial organs • The non-functional organs are termed as vestigial organs. • There are more than 100 vestigial organs are found in humans too !!! • Muscles to move ears. • Hair on body. • Nictitating membrane. • Candal vertebrae • Vermiform appendix. • Segmental muscles on abdomen.

11. Evidences from embryology. • “ONTOGENY RECAPITULATES PHLOGENY” This is the Ernst Haeckel's theory of recapitulation or biogenetic law.

12. OTHER EVIDENCE OF EVOLUTION http://evolution.berkeley.edu/evolibrary/home.php

13. Representative Primates • The (a) tarsier, (b) lemur, and (c) lion-tail macaque monkey all have relatively flat faces, with forward-looking eyes providing binocular vision. All also have color vision and grasping hands. These features, retained from the earliest primates, are shared by humans.

14. Theories regarding Evolution • Lamarck’s theory of inheritance of acquired characters • August Weismann's germ plasm theory • Darwin's theory of natural selection • Mutation theory by Hugo de vries • Synthetic theory of evolution

15. Charles Darwin • He observed much variation in related or similar species of plants and animals that were geographically isolated from each other. • He says- “I have called this principle, by whicheach slight variation, if useful, is preserved, by the term Natural Selection.”

16. Darwin’s theory • Within any population there is a natural variation. some individual have more favorable variations than others. • Even though all species produce a large number of offspring's ,population remain fairly constant naturally. • This is due to the struggle between members of the same species and different species for food, space & mate • The struggle for survival within populations eliminates the unfit individuals. The fit individuals possessing favorable variation’s survive and reproduce. This is called natural selection. • The individual having favorable variations pass on these variations to their progeny from generation to generation. • These variation when gets accumulated over a longer period of time, leads to origin of new species.

17. Lamarck's theory • Modification which an organism acquire in adaptation to the environment which it meets during it’s life time are automatically handed over to it’s descendants there by becoming part of heredity.

18. August Wiseman Theory • August Wiseman strongly criticized Lamarckism …. • When a tail of rat is been cut for 21 generations then also a tailless rat is never born…

19. Mutation & Synthetic theory • Mutations are sudden inheritable changes in the genetic constitution of an organism due to which new species are formed • Synthetic: Darwin's theory cannot explain how variation arises so Darwin's theory was modified and it resulted into the modern synthetic theory of evolution.

20. MECHANISMS FOR EVOLUTION • HOW CAN THE GENE POOL CHANGE? • MUTATION • GENETIC DRIFT • GENE FLOW

21. MUTATION GENETIC DRIFT GENE FLOW - MIGRATION

22. WHAT IS SPECIATION? • GEOGRAPHIC ISOLATION • REPRODUCTIVE ISOLATION

23. Lucy • In 1974, a skeleton was found in Africa. The bones were those of a female, about 20 years old or so when she died. Scientists named her Lucy. About 3 million years ago, when Lucy was alive, she was about 4 feet tall and weighed about 50 pounds. Scientists suspect that she fell into a lake or river and drowned.

24. Handy Man • The Stone Age refers to the materials used to make man-made tools. In the Stone Age, man made tools out of stone. “Handy Man” was one of the first hominids to use stone tools. • Hunters & Gatherers: The Old Stone Age people were hunters/gatherers. We know this because scientists have found fossils and artifacts, which reveal traces of their life.These people did not plant crops. They gathered wild fruits, nuts, berries, and vegetables.

25. Handy Man… • These early human-like hominids were taller and smarter than Lucy’s people, but they did not know how to make fire. • When they broke camp, they probably tried to bring fire with them by carrying lit branches to use to start a new campfire. • If their branches went out, they did without fire until they found something burning.

26. Upright Man • Many years passed. Another group of man was born. Scientists nicknamed this group “Upright Man”. Upright Man did know how to make fire. • That changed everything! • People began to cook their food, which helped to reduce disease. People collected around the fire each night, to share stories of the day's hunt and activities, which helped to develop a spirit of community.

27. Upright-Man • These Stone Age people were about the same size as modern humans. Their tool-making skills were considerably improved. Their weapons included stone axes and knives. • Because Upright Man could make fire, he was free to move about in search of food. He did not have to worry about freezing. He made warm clothes from animal skins. At night, he built a campfire to cook his food and to stay warm.

28. Man leaves home • About one million years ago, Upright Man began to slowly leave Africa. These early people began to populate the world. • They did not need a boat. The Ice Age was here! They traveled across giant walkways of frozen ice, over what later would become vast rivers and seas. • Scientists have found artifacts of their tools and weapons, which help us to understand how they lived, where they went, and how they got there.

29. Neanderthals • One day, scientists found a new skeleton. This skeleton was from another group of early men. Scientists named this man Neanderthal man, after the valley in which the skeleton had been found. • Scientists announced that these early men were dim-witted brutes, who walked with bent knees, with their heads slung forward on their big necks. Could these early people really be our ancestors?

30. Neanderthals • But scientists had made a mistake! • The bones were bent because they were part of the skeleton of an old man suffering from arthritis! Arthritis is a disease that bends and cripples bones.

31. Neanderthals • Still, Neanderthals were different from other species of early humans. They were tall and smart, and used caves as their homes. They were great hunters. • Considering how smart they were, and how advanced for their time, scientists are puzzled that the Neanderthals were one of the early species of man to die out. Many species of man died out in these early days. But why the Neanderthals? It is a history mystery.

32. Cro-Magnon Man • Another group of early men stood out during this period. Scientists nicknamed this group “Cro-Magnon man”. • Cro-Magnon man lived in Europe. • This group did not live a life of constant struggle for survival because they worked together to provide food for their tribe.

33. Cro-Magnon Man • These Stone Age people learned to cure and store food for the long winter. They used traps, which allowed them to catch food while they were busy doing something else. Fisherman used nets woven from vines and fishhooks. • Some groups built rafts and canoes to catch bigger fish in deeper waters. • They made clothing and jewelry. They invented the bow and arrow.

34. Cave Paintings • Cro-Magnon man did something rather unusual. For some reason, he drew paintings deep inside dark caves, on cave walls. • His paintings were added to the paintings already on the cave walls, left by other Cro-Magnon men.

35. CRITICISM OF EVOLUTION • "The second law of thermodynamics is an expression of the universal law of increasing entropy. It means that things can't get better with time, only worse. For example if you leave your car in the yard for a long time, it can only get rusty and in worse shape. • From the maggots experiment it has been proved that “Life comes only from life.” But in evolution life is believed to come from nothing. • 3. Earth is billions of years or more old. The sun shrinks at an average of five feet every hour? This would mean that 100 thousand years ago, life wouldn't have been possible because the sun would be twice it's size. Life on Earth would be impossible at that heat level.

36. CRITICISM OF EVOLUTION 4. If the Evolutionary theory is correct, then why do we have so many missing links? It takes millions of years for something to change, say a fish come out of water, then millions of millions of millions of dead fish would be everywhere. As you walk out to your car you'd trip over the body of one these transitionals. You would be able to go dig in the back yard and find the remains of all these dead creatures. If you've seen the movie Evolution, note the scene where they go into a giant field and see dead dragon looking things all over the place. That's how it would be. 5. Evolution is said to happen because of mutations and such. In this case, what about the fact that mutated animals are sterile and can't reproduce. What explains that?

37. CRITICISM OF EVOLUTION 6. Everyone knows that the first thing Neil Armstrong said when he stepped out onto the moon, was "That's one small step for man, one giant leap for mankind" but not many know the second thing he said. He made a comment about the dust on the moon. NASA scientist had anticipated the moon being covered in dust, because it too should have been really old. They were expecting feet of dust and all they got was a few inches. This shows that the world couldn't be that old, or at least the moon. 7. The moon moves away from Earth a certain amount each year. If the world was so old, the moon would be gone. We wouldn't even be able to see it.

38. Conclusions • Change is the law of nature. • Lot of changes have taken on planet earth since it’s origin. • Simpler life form evolved that were in equilibrium with the earth's atmosphere at that time more complicated life form evolved later on . • The history of human evolution may or may not be very old but there are continuous and gradual changes in the genetic pool of the species which leads to mutations and variation which is considered as driving force of evolution.