Evolution ???

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HUMAN EVOLUTION
PRESENTATION BY:
RAHUL PATEL
09EC
EVOLUTION v/s CREATIONISM
The Bible teaches that
God created man
So God created man in
his own image, in the
image of God he created
him; male and female
Evolution begins with
the assumption that
man has evolved from
ape-like creatures
Pick your relative
INTRODUCTION
EVOLUTION = E (From) + Volvere = THE Act Of Unfolding
Evolution is the
gradual descent
with modification.
(Charles Darwin)
Evolution is a discontinuous
process rather than gradual
one. (Hugo de Vries)
EVIDENCES OF EVOLUTION
1.Evidences from Fossils
2.Evidences from Biogeography
3.Evidences from anatomy and
morphology
4.Evidences from embryology
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
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
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
 HOMOLOGOUS STRUCTURES
 ANALOGOUS STRUCTURES
Vestigial organs
 The non-functional organs are
termed as vestigial organs.
 There are more than 100
vestigial organs are found in
humans too !!!
I.
Muscles to move ears.
II. Hair on body.
III. Nictitating membrane.
IV. Candal vertebrae
V. Vermiform appendix.
VI. Segmental muscles on
abdomen.
Evidences from embryology.
 “ONTOGENY RECAPITULATES PHLOGENY”
This is the Ernst Haeckel's theory of recapitulation or
biogenetic law.
OTHER EVIDENCE OF EVOLUTION
http://evolution.berkeley.edu/evolibrary/home.php
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.
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
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 which
each slight variation, if
useful, is preserved, by the
term Natural Selection.”
Darwin’s theory
 Within any population there is a natural variation. some
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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.
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.
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…
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.
MECHANISMS FOR EVOLUTION
 HOW CAN THE GENE POOL CHANGE?
 MUTATION
 GENETIC DRIFT
 GENE FLOW
WHAT IS SPECIATION?
 GEOGRAPHIC ISOLATION
 REPRODUCTIVE ISOLATION
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.
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.
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.
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.
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.
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.
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 dimwitted brutes, who walked
with bent knees, with their
heads slung forward on their
big necks. Could these early
people really be our
ancestors?
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.
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.
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.
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.
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 CroMagnon men.
CRITICISM OF EVOLUTION
1. "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.
2. 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. 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.
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?
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.
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.
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