An informative, rather enjoyable presentation & explanation of Neo-Darwinism (evolution) based on the theory in my 12th-grade book.
Remember: When assigned a group project, always give proper and equal time to each member. (Designed for teamwork)
Discovery of an Accretion Streamer and a Slow Wide-angle Outflow around FUOri...
Neo darwinism - post02
1. Mr. A, Mr. B
& Ms. C
PRESENT
NEO-DARWINISM
TOPICS COVERED:
INTRO. & EVIDENCES OF EVOLUTION:
EVIDENCE FROM BIGRAPHY +
EVIDENCE FROM PALEONTLOGY +
EVIDENCE FROM COMPARATIVE ANATOMY
3. LAMARCK AND
DARWIN’S IDEAS
What is Neo-Darwinism?
• Before the proposal of these ideas, practically nothing was
known about heredity.
• The emergence of population genetics (Population genetics is
a subfield of genetics that deals with genetic differences within and
between populations, and is a part of evolutionary biology.) has
provided a clear understanding of inheritance and variation
among the individuals of a population
• This review of the theory of natural selection in terms of
modern population genetics is sometimes called Neo-
Darwinism.
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4. EVIDENCES OF
EVOLUTION
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• EVIDENCE FROM BIOGEOGRAPHY
• EVIDENCE FROM PALAEONTOLOGY
• EVIDENCE FROM COMPARATIVE ANATOMY
• EVIDENCE FROM MOLECULAR BIOLOGY
6. Biogeograph
y
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Definition:
• - Study of geographical distribution
of plants and animals on Earth.
• EVIDENCES:
• Evidences about: Prehistoric climates, habitats
and animal distribution.
• Life forms of different parts of the world and
their evolutionary history.
7. 7
BY …
SPECIFIC
PATTERN OF
DISTRIBUTION:
• Darwin noticed lacking of rabbit
population.
• In South America, even though
environment was suitable.
• Conclusion: No rabbits in South
America.
• They originated from somewhere
else.
• No means to reach South America.
8. Factors Inhibiting
Distribution of
Organisms:
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• Bio-geographical studies: Species having
restricted distribution from the centre of origin.
• Reason: (barrier might be physical)
• Ocean, Desert or Mountains.
• Barrier might be environmental:
• Unfavourable climate.
• Barrier might be ecological:
• Food chains and competition for shelter.
10. Palaeontology
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Definition:
• - The science of discovery, identification
and interpretation of fossils.
• EVIDENCE:
• Succession of fossil forms strong
evidence in favour of evolution.
• Provision of visual record in a complete
series showing evolution of species.
11. Oldest Known
Fossils
11
...
• Evidences from other biological
sciences:
• Prokaryotes as the ancestors of all life.
• Prediction that prokaryotes should all
eukaryotic life.
• The oldest known fossils are
prokaryotes.
12. Chronological
Sequence of
Vertebrate Fossil
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• Chronological sequence of different classes of vertebrates in
the fossil record.
• Earliest Vertebrates: Fossil fishes.
• Amphibians > Reptiles > Mammals > Birds.
• Sequence is consistent and complexity of their organ
system.
• Tracing history of a particular organism
• Modern day horse Equus.
• Earliest horses had four toes.
• No. of toes reduced to three over time.
• Modern horses to one, large central toe ending in hoof.
• Evidence of fossil record, support the common descent
hypothesis.
14. Comparative Anatomy
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Definition:
• - Comparative study of the anatomy of groups of
animals or plants reveals that certain parts of the
organism have similarities in structures, while
others have similarities in functions.
Homologous Organs Represent Divergent
Evolution
• Body parts, similar in structure and different in
function; inherited from common ancestor
Homologous structures.
• Study is known as Homology.
• Pattern of evolution in which, different species are
evolved from common ancestors at different habitats
is Divergent Evolution.
15. EXAMPLE
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• Basic structure of all flowers same.
• Same structural plan: Limb-bone pattern of all tetra
pod from amphibian to mammals.
• Known as Pent dactyl limb.
• Vertebrate Forelimbs for flights. (E.g. Bats and
Birds)
• Orientation during swimming. (E.g. Whales and
Dolphins)
• Running. (E.g. Horses)
• Climbing. (E.g. Arboreal lizard)
• Or Swinging from tree branches.
• All vertebrate forelimbs have same sets of bones
similarly organized; with non-similar functions.
21. Analogous Organs
Represent
Convergent Evolution
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• Organs with similar functions, but different
structures are known as Analogous Organs.
• E.g. Wings of bird and butterfly.
• Structures of evolutionary interest.
• Demonstrate that population with separate
ancestries, adopt ways similar to what
environment demands.
• Pattern of evolution in which different species
evolved from different ancestors in common
habitat is Convergent Evolution.
22. Answer this:
22
1. What is convergent evolution?
2. How analogous organs represent
convergent evolution?
• - Make a list of the vestigial structures found in
man and categorize them in homologous and
analogous structures.
24. Molecular Biology
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Definition:
• - The branch of biology that deals with the structure
and function of the macromolecules (e.g. proteins and
nucleic acids) essential to life.
• EVIDENCE:
• All living organisms use same basic biochemical
molecules. (DNA, ATP or identical enzymes)
• Organisms utilize same DNA triplet code and twenty
amino acids in proteins.
• Share the same types of interons.
• Cytochrome “c” used by electron transport system.
• No functional reason for similarity of elements.
• Similarity explained by descent from common
ancestor.
25. Science, Technology and
Society Connections 01
Describe and analyze examples of
technology that have extended or
modified the scientific understanding of
evolution (e.g., the contribution of
radiometric dating to the paleontological
analysis of fossils).
• The method of radioactive/radiometric
dating
• Living things have a certain fixed ratios of
radioactive and stable isotopes of carbon 12C
and 14C.
• The half life is the amount of time it takes for
one half of the initial amount of the parent
radioactive isotope, to decay to the daughter
isotope.
• FOR EXAMPLE: Carbon 14C has a half-life of
5600 years
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26. Science, Technology and Society Connections 02
List the vestigial structures found in man and categorize
them in homologous or analogous structures.
• Human vestigial organs are those organs that have
lost all or most of their original function through
evolution.
• About 90 such structures are present in our bodies.
• FOR EXAMPLE:
1. Vermiform appendix
2. Coccyx or tailbone (is the remnant of lost tail)
3. The Wisdom teeth (human ancestors used to
help in grinding down plant tissue.
4. Human ear muscles are non-functional and
minimally developed
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27. Skills: Analyzing and Interpreting
What factors have contributed to the dilemma that pharmaceutical
companies face in trying to develop new antibiotics because so
many micro-organisms are resistant to existing antibiotics?
• Antibiotic resistance is a type of drug addiction where a
micro-organism is able to survive exposure to an
antibiotic.
• While induced genetic mutation that impose
resistance to the antibiotic may be passed to the
offspring.
• This makes the antibiotic non-effective on the
existing microbe.
• Now, the factories or pharmacies would have to
develop new i.e. unrecognized formulae to kill the
microbe.
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