Our Complete PPT on EVOLUTION. Hope You like it, And this turns informative for you.

2. 1. 1. Introduction to Evolution
2. 2.History of evolutionary
thought
3. Heredity
4. Variation
• 4.1 Mutation
• 4.2 Sex and recombination
• 4.3 Gene flow
5. Mechanisms
• 5.1 Natural selection
• 5.2 Biased mutation
• 5.3 Genetic drift
• 5.4 Genetic hitchhiking
• 5.5 Gene flow
6. Outcomes
• 6.1 Adaptation
• 6.2 Coevolution
• 6.3 Cooperation
• 6.4 Speciation
• 6.5 Extinction
7. Conclusion

5. History of Evolutionary Thought
• The word "evolution" in its
broadest sense refers to change or
growth that occurs in a particular
order.
• That use of the term dates back to
the ancient Greeks, but today the
word is more often used to refer
to Darwin's theory of evolution by
natural selection. This theory is
sometimes crudely referred to as
the theory of "survival of the
fittest.“

6. •Greek and medieval references to "evolution" use it as a
descriptive term for a state of nature, in which everything in
nature has a certain order or purpose. This is a teleological
view of nature. For example, Aristotle classified all living
organisms hierarchically in his Greatscala naturae or Great
Chain of Being, with plants at the bottom, moving through
lesser animals, and on to humans at the pinnacle of creation,
each becoming progressively more perfect in form. It was the
medieval philosophers, such as Augustine who began to
incorporate teleological views of nature with religion: God is
the designer of all creatures, and everything has a purpose
and a place as ordained by Him.

7. Several views on Evolution
•Ancient Greek Views
•Medieval Views
•In Modern Philosophy
•In German Idealism
•Darwin’s View
•Spencer’s View

8. HEREDITY
•Evolution in organisms occurs through changes in heritable
traits—the inherited characteristics of an organism. In
humans, for example, eye colour is an inherited characteristic
and an individual might inherit the "brown-eye trait" from
one of their parents inherited traits are controlled by genes
and the complete set of genes within an organism's
genome (genetic material) is called its genotype.
•The complete set of observable traits that make up the
structure and behaviour of an organism is called its
phenotype. These traits come from the interaction of its
genotype with the environment.As a result, many aspects of
an organism's phenotype are not inherited

9. •Heritable traits are passed from one generation to
the next via DNA molecules, that encodes genetic
information
•Heritability may also occur at even larger scales.
•Other examples of heritability in evolution that
are not under the direct control of genes include
the inheritance of cultural traits
and symbiogenesis

10. Variation
• An individual organism's phenotype results from
both its genotype and the influence from the
environment it has lived in.
• A substantial part of the phenotypic variation in a
population is caused by genotypic variation.
• The modern evolutionary synthesis defines
evolution as the change over time in this genetic
variation.
• The frequency of one particular allele will become
more or less prevalent relative to other forms of
that gene. Variation disappears when a new allele
reaches the point of fixation—when it either
disappears from the population or replaces the
ancestral allele entirely.

11. • Natural selection will only cause evolution if
there is enough genetic variation in a
population.
• Before the discovery of Mendelian genetics,
one common hypothesis was blending
inheritance. But with blending inheritance,
genetic variance would be rapidly lost, making
evolution by natural selection implausible.
• The Hardy–Weinberg principle provides the
solution to how variation is maintained in a
population with Mendelian inheritance. The
frequencies of alleles (variations in a gene) will
remain constant in the absence of selection,
mutation, migration and genetic drift.

12. • Variation comes from mutations in the
genome, reshuffling of genes through sexual
reproduction and migration between
populations (gene flow).
• Despite the constant introduction of new
variation through mutation and gene flow,
most of the genome of a species is identical in
all individuals of that species.
• However, even relatively small differences in
genotype can lead to dramatic differences in
phenotype: for example, chimpanzees and
humans differ in only about 5% of their
genomes.

13. MUTATION
• Mutations are changes in the DNA
sequence of a cell's genome. When
mutations occur, they may alter the
product of a gene, or prevent the
gene from functioning, or have no
effect.
• Mutations can involve large
sections of a chromosome
becoming duplicated (usually
by genetic recombination), which
can introduce extra copies of a
gene into a genome.
• The generation of new genes can
also involve small parts of several
genes being duplicated, with these
fragments then recombining to
form new combinations with new
functions.

14. SEX AND
RECOMBINATION
• In asexual organisms, genes are
inherited together, or linked, as
they cannot mix with genes of
other organisms during
reproduction. In contrast, the
offspring of sexual organisms
contain random mixtures of
their parents' chromosomes that
are produced through
independent assortment. In a
related process
called homologous
recombination, sexual organisms
exchange DNA between two
matching chromosomes

15. GENE FLOW
• Gene flow is the exchange of genes
between populations and between
species. It can therefore be a source of
variation that is new to a population or
to a species. Gene flow can be caused
by the movement of individuals
between separate populations of
organisms, as might be caused by the
movement of mice between inland and
coastal populations, or the movement
of pollen between heavy metal tolerant
and heavy metal sensitive populations
of grasses.
• Gene transfer between species includes
the formation of hybrid organisms
and horizontal gene transfer. Horizontal
gene transfer is the transfer of genetic
material from one organism to another
organism that is not its offspring; this is
most common among bacteria

16. MECHANISM • From a Neo-Darwinian
perspective, evolution occurs
when there are changes in
the frequencies of alleles
within a population of
interbreeding organisms. For
example, the allele for black
color in a population of
moths becoming more
common. Mechanisms that
can lead to changes in allele
frequencies include natural
selection, genetic
drift, genetic hitchhiking,
mutation and gene flow.

17. NATURAL SELECTION
Evolution by means of natural selection is the process by
which traits that enhance survival and reproduction become
more common in successive generations of a population. It
has often been called a "self-evident" mechanism because it
necessarily follows from three simple facts:
• Variation exists within populations of organisms with
respect to morphology, physiology, and behavior
(phenotypic variation).
• Different traits confer different rates of survival and
reproduction (differential fitness).
• These traits can be passed from generation to generation
(heritability of fitness).

19. BIASED MUTATION
• Notwithstanding being a noteworthy wellspring of variety, mutation may
likewise work as a system of evolution when there are distinctive
probabilities at the atomic level for various mutations to happen, a procedure
known as mutation bias.
• In the event that two genotypes, for instance one with the nucleotide G and
another with the nucleotide A similarly situated, have a similar wellness,
however change from G to A happens more regularly than transformation
from A to G, then genotypes with A will have a tendency to evolve.
• Different insertion versus deletion mutation biases in different taxa can
prompt to the evolution of various genome sizes. Formative or mutational
biases have likewise been seen in morphological evolution. For instance, as
per the phenotype-first hypothesis of evolution, mutations can in the long
run cause the genetic assimilation of traits that were previously induced by
environment.

20. GENETIC DRIFT
• Genetic drift is the change in allele frequency from one era to the
following that happens on the grounds that alleles are liable to examining
blunder.
• Therefore, when specific forces are absent or moderately feeble, allele
frequencies tend to "drift" upward or descending randomly (in a random
walk).
• This drift stops when an allele in the long run gets to be settled, either by
vanishing from the population, or replacing alternate alleles completely.
• Genetic drift may in this manner kill a few alleles from a populace
because of chance alone. Indeed, even without specific powers,
hereditary float can bring about two separate populaces that started with
the same genetic structure to drift separated into two disparate
populations with various arrangements of alleles.

22. .
Genetic hitchhiking
•Recombination permits alleles on a similar strand of DNA to end up
isolated. Be that as it may, the rate of recombination is low (roughly two
occasions for each chromosome per generation).
•Thus, genes near one another on a chromosome may not generally be
rearranged far from each other and genes that are near one another have
a tendency to be acquired together, a phenomenon known
as linkage. This tendency is measured by discovering how frequently two
alleles happen together on a single chromosome thought about
to expectations, which is called their linkage disequilibrium.
•An arrangement of alleles that is normally acquired in a gathering is
called a haplotype, natural determination can drive a selective sweep that
will likewise bring about alternate alleles in the haplotype to end up more
regular in the population; this impact is called genetic hitchhiking .

23. .

24. .
Gene flow
•Gene flow includes the trading of qualities amongst populaces and
between species. The nearness or nonattendance of Gene flow in a
general sense changes the course of evolution.
•Because of the many-sided quality of organisms, any two totally
detached populaces will in the end evolve genetic incompatibilities
through impartial procedures, as in the Bateson-Dobzhansky-Muller
model, regardless of the possibility that both populaces remain
essentially identical as far as their adaptation to nature.
•On the off chance that genetic differentiation between
populations develops, gene flow between populaces can
present characteristics or alleles which are disadvantageous in
the local populace.

25. .

26. .
•This may prompt to living beings inside these populaces advancing
components that forestall mating with hereditarily far off populaces,
in the long run bringing about the presence of new species
• Exchange of genetic information between people is on a very basic
level vital for the improvement of the biological species idea.
•Amid the advancement of the present day union, Sewall Wright
created his shifting balance theory, which respected quality stream
between incompletely disengaged populaces as an essential part of
versatile evolution. However, as of late there has been considerable
feedback of the significance of the shifting balance theory.

27. .
•Trade of genetic information between individuals is generally
essential for the advancement of the biological species idea.
•Amid the improvement of the present day amalgamation, Sewall
Wright created his shifting balance theory, which respected quality
stream between somewhat detached populaces as an essential part of
versatile advancement. In any case, as of late there has been
considerable feedback of the significance of the shifting balance
theory.

28. ADAPTATION
A baleen whale skeleton, a and b label flipper bones, which were adapted
from front leg bones: while c indicates vestigial leg bones, suggesting an
adaptation from land to sea.

29. •Adaptation is the procedure that improves living beings suited to
their habitat.[Also, the term adjustment may allude to a quality that
is vital for a creature's survival.
• For instance, the adaptation of horses' teeth to the pounding of grass.
By utilizing the term adaptation for the developmental procedure
andadaptive trait for the item (the real part or capacity), the two
faculties of the word might be recognized.
•Adaptations are produced by natural selection.
ADAPTATION

30. The following definitions are due to Theodosius Dobzhansky:
•Adaptation is the transformative procedure whereby a life form turns
out to be better ready to live in its environment or living spaces.
•Adaptedness is the condition of being adjusted: how much a living
being can live and recreate in a given arrangement of natural
surroundings.
•An adaptive trait is a part of the formative example of the living
being which empowers or improves the likelihood of that creature
surviving and recreating.

31. •Adaptation happens through the slow change of existing structures.
Thusly, structures with comparative interior association may have
distinctive capacities in related living beings. This is the aftereffect of
a single ancestral structure.
•Numerous qualities that seem, by all accounts, to be straightforward
adjustments are in fact exaptations: structures initially adjusted for
one capacity, however which fortuitously turned out to be to some
degree helpful for some other capacity all the while.
•One case is the African lizard Holaspis guentheri, which built up a to
a great degree level set out toward covering up in hole, as can be seen
by taking a gander at its close relatives. Nonetheless, in this species,
the head has turned out to be flattened to the point that it helps with
coasting from tree to tree—an exaptation.

32. Coevolution
•In biology, coevolution occurs when changes in species' hereditary
creations correspondingly influence each other's development.
•An illustration is the creation of tetrodotoxin in the rough-skinn
newt and the development of tetrodotoxin resistance in its
predator, the common strap wind. In this predator-prey match,
an evolutionary arms race has created elevated amounts of poison
in the newt and correspondingly abnormal amounts of poison
resistance in the snake
•One more example.

33. Coevolution

34. Speciation

35. Speciation
•Speciation is the procedure where an animal categories veers into at
least two relative species.
•There are various approaches to characterize the idea of "species."
The decision of definition is subject to the particularities of the
species concerned.
•For instance, a few species ideas apply all the more promptly toward
sexually replicating life forms while others loan themselves better
toward agamic life forms.
•Regardless of the differences of different species ideas, these
different ideas can be set into one of three expansive philosophical
methodologies: interbreeding, biological and phylogenetic.

36. Extinction
•Extinction is the end of an organism or of a gathering of creatures
(taxon), ordinarily a species. The snapshot of termination is by and
large thought to be the demise of the last individual of the species, in
spite of the fact that the capacity to breed and recoup may have been
lost before this point.
•More than 99 percent of all species, adding up to more than five
billion species, that ever lived on Earth are assessed to be wiped out.
•Mass extinctions are moderately uncommon occasions; be that as it
may, disconnected terminations are very normal. Just as of late have
eradications been recorded and researchers have ended up frightened
at the momentum high rate of annihilations.

38. Conclusion
The evolution of monkey to man has continually been a
desirable topic. wherever did we have a tendency to come
back from? it's been determined by biochemists that citizenry genetic
makeup is comparable there to of the many primates, which means we
have a tendency to should all share a standard antecedent. Humans
share associate degree astounding seventeen similarities
in aminoalkanoic acid sequences found in Hb with chimpanzees,
and sixteen similarities with gorillas In distinction, humans
share solely 5 similarities with chickens or frogs. Different similarities
between humans and monkeys is seen in their
teeth. man share identical variety of incisors, canines, premolars, and
molars as different primates.