DARWINISM

Charles Robert Darwin was undoubtedly the first naturalist who put the idea of Organic evolution on sound footing.
His statements and theories were based upon practical experiences and large number of proofs which he collected directly from the nature.
He devoted his whole life for the purpose of finding out proofs in support of the theory of organic evolution.

1. Uttam Memorial College Raigarh (C.G.)
Subject : ZOOLOGY II
Submitted by :
SHRADDHA PATEL
Guided by :
Ms. POOJA SAO
Class : BSC (BIO) 2
ND
YEAR

2. DARWINISM

3. ●Framing of the DARWINISM
●Postulates “Theory of Natural Selection”
●Critics
●Favour
●Supplementary Theory Of DARWIN
●NEO-DARWINISM
●REFERENCE
Synopsis

4. 01
FRAMING OF THE
DARWINISM

5. CHARLES ROBERT DARWIN
•DOB: 12 February 1809
•BIRTHPLACE: Shrewsbury, England
•He was the great English Naturalist
•Author of ‘Origin of Species'

6. HMS BEAGLE (Her majesty’s ship)
•The journey initially planned for 2
years but it lasted for5 years
(1831-1836).
•Ship started from Plymouth
[England] in December (1831) &
returned back in October (1836).

7. GALAPAGOS ISLAND
•Volcanic islands
•Guano islands
•Darwin called Galapagos Island
as 'LIVING LABORATORY OF
EVOLUTION’
•Darwin observed many unusual
animals here like –GIANT
TORTOISE, GIANT
IGUANAS,FINCHES

8. FINCHES
•There were insectivorous tree
finches, insectivorous ground
finches, vegetarian finches,seed
eating finches, cactus eating
finches.
•Finches provide an example of
Adaptive radiationor Divergent
evolution

9. ALFRED RUSSEL WALLACE
•In (1858) Darwinreceived few research papers by
Alfred Russel Wallace titled “On the tendencies of
varieties to depart indefinitely from the original type.”
•Wallace studied flora and fauna of Malay
Archipelago [present day Indonesia and Malaysia].
•Darwin friend Joseph Dalton Hookerand Charles
Lyelladvised Darwin to present his research papers
publically.

10. HOOKER & LYELL
•Hooker and Lyell arranged a paper presentation for Darwin
and Wallace in front of “Linnean Society of London” but
both author didn’t appear so the papers were jointly read by
Hooker and Lyell.
•Darwin’s paper were more detailed and with better
evidencesso he got more credit.

11. ORIGIN OF SPECIES
•In NOVEMBER (1859), Darwin published his “Theory of Natural
Selection” in the book “ORIGIN OF SPECIES”
•Actual name of the book is “ ON THE ORIGIN OF SPECIES BY
MEANS OF NATURAL SELECTION” or “THE PRESERVATION OF
FAVOURED RACES IN THE STRUGGLE FOR LIFE”.
•Theory of Natural Selectionhas been jointly proposed byDARWIN&
WALLACE

12. 02
Postulates

13. 1.OVERPRODUCTION
All living beings have an inherent tendencyto produce offspringsof
their own kind inlarge no. for the perpetuation of their race
Example: A Rabbitproduces about 6 young ones in a litter [at one
time] & four litter per year & the young ones starts reproducing at
the age of 6 month.

15. 2. STRUGGLE FOR EXISTENCE
1.Intraspecific competition: Competition between1 Species.
2.Interspecific competition: Competition between2 different
Species.
3.Interaction with environment: Struggle between the animals
and theirenvironment.

16. 4.NATURALSELECTION
•Also known as the survival of the fittest
•Fit : Suruive
•Unfit : elminate
5. Origin of Species
3.UNIVERSAL OCCURRENCE OF
VARIATION

17. 03
CRITICS

18. CRITICIZED BY: Sir Richard Owen & Adam Sedgwick
1.Main drawback of the theory is lack of knowledge of genetics.
2.Darwin failed to recognise the source of variations.
3.Darwin’s theory explains the SURVIVAL OF THE FITTEST
but doesnot explain ARRIVAL OF THE FITTEST.
4.This theory doesnot explain the presence of over specialised
organslike antlers of deer & tusk of elephants.[ To explain
this point he gave the theory of Sexual selection].

19. 04
FAVOUR

20. 1. RATE OF REPRODUCTION : Rate of
Reproduction is many times higher than the rate of
suruival in all organism.
2.Limitation of Resources: Food, space and other
resources are limited.
3. STRUGGLE FOR EXISTENCE : Competition or
struggle for existence is seen in all organisms.

21. 05
SUPPLEMENTARY THEORY
OF DARWIN

22. THEORY OF
SEXUAL SELECTION

23. TUSK OF ELEPHANT

24. ANTLERS IN MALE DEER

25. BRILLANTLY COLOURED
FEATHERS OF PEACOCK

26. Fossil record
Bones
Neptune is an ice giant
Shells
The Sun is our star
Leaf
Ceres is in the asteroid belt
Nests
Mercury is the smallest
Teeth
Pluto is no longer a planet
Footprints
Venus has a beautiful name
VOCAL SACS IN MALE FROG

27. 06
NEO-DARWINISM

28. NEO-DARWINISM
1.It is the modified form of DARWINISMto remove it’s short
comings.
2.It gradually changed into MODERN SYNTHETIC THEORY
OF EVOLUTION.
3.Neo-Darwinismm was proposed by : T.Dobzhansky,JBS
Haldane,R.A. Fischer, H.B.O. Kettlewell,Herbert
Spencer, Gregor Johann Mendel, Ernst Mayr.
4.It is the merger of Darwinian selection & genetic theory.

29. 07
REFERENCE

30. Organic Evolution
by : Veerbala Rastogi