Evolution

2. • Is an inherited change in
the traits of organism
over time.
• It is a process wherein
new species came from
preexisting species.

3. Jean-Baptiste de Lamarck , a French
biologist who first suggested that
organisms undergo evolution.
• He proposed that all organisms evolve
in response to their environment.
• He also studied fossils and organisms,
which led him to formulate theories
regarding evolution.
• His theory explained why organisms
change over time.

4. “Organisms change
because they need to and
as a response to the
environment, making their
traits more adaptable.”
• The traits that the
organisms manifest are
products of their altered
behaviors.

5. “Organisms developed
characteristics by the use and
disuse.”
• Lamarck explained that
organisms can reshape their
traits depending on the
importance of those traits to
them.
• An organism will develop a
trait that is useful to it, and
it will lose a trait that is

6. “An organism can develop
acquired traits as adaptations,
and these traits acquired in its
lifetime could be passed on to
its offspring.”

7. Charles Darwin, an English Naturalist,
contributed the widely accepted theory of
evolution by means of natural selection.
• His theory of natural selection provided
the foundation for understanding the
diversity of species on Earth.
• Species refers to a group of organisms
that have similar features and
characteristics and can produce fertile
offspring in a specific environment.

8. Variation of Organism
• Organisms vary in their physical,
functional, and behavioral
characteristics.
• No two individuals are the same.
• Variation is important in natural
selection because it allows a specific
kind of species to survive more than
other members.
• Variations of organisms are passed on
to the next generation.

9. Survival of the Fittest
• Competition is a struggle for existence.
• All organisms will struggle for living
space and food in the natural world.
• Because of this struggle for survival,
organisms are compelled to change to
fit into the environment.
• Failure to do so will result in extinction
– a process wherein all individuals of a
given species cease to exist.

10. Adaptation to the environment
• Organism who can adapt to their
environment would most likely survive
and produce an offspring with adaptable
traits.
• Adaptation is the process of being better
suited to the environment.
• The fittest organisms would avoid
extinction and have the ability to
reproduce healthy offspring, which will
guarantee transmission of adaptable traits

11. Natural Selection
• Environmental conditions affect the
survival of organisms.
• Only those organisms that can adapt
to new environmental conditions will
survive and reproduce in greater
numbers than those without the
capacity to adapt.

12. Process of Speciation
• When new species come to
existence, speciation occurs.
• This process happens when
favorable traits are gradually
accumulated by the new species
and the unfavorable traits
disappear.

14. • It is a scientific study of prehistoric
life, which includes the identity,
origin, environment, and evolution
of organisms.
• Fossils are considered as a direct
evidence of ancient life.
• Using fossil records, Paleontologist
can identify organisms that
flourished millions of years ago and
reconstruct the environment they
inhabited.

15. A. Body Fossils
– These includes the discovered
bones, teeth, shells, and other
hard materials of once-living
organisms.
B. Trace Fossils
– These includes imprints of leaves,
stems, burrows, tracks,
footprints, coprolites(fossilized
feces).

17. a gradual process that starts when
volcanic ash or sediments cover an
organism or its traces.
Fossils can also be formed by:
A. Petrification
B. Freezing
C. Desiccation
D. Carbonization

18. 1. Petrification/Petrifaction
• It starts when water infiltrates
the remains buried underneath
and inorganic compounds are
dissolved replacing minerals in
bones and other hardened
tissues.
• Accumulation of sediments exerts
pressure on the burial site of the
organism.

19. 2. Freezing
• It occurs when organism’s
remains get frozen.
• Examples of the effects of
freezing are the remains of
woolly mammoths and
rhinoceroses during the ice
age.

20. 3. Desiccation
• It occurs when the remains
dry up for a long period of
time.
• Example of the effect of
desiccation is the remains
of giant ground sloths in
desert or dry areas.

21. 4. Carbonization
• It occurs when the only
remaining component of an
organism is carbon – the most
common component in plant
fossils.
• Example of this is Amber, a
fossilized sap of ancient pine
trees that may contain fossil
insects or other small animals
trapped in the sticky sap.

22. It is the study of rock layers, wherein scientist compare large
and microscopic fossils located on different rock layers to assign
relative ages of rocks.
Index Fossils
• It is used to determined the
relative age of the rocks.
• Examples of index fossils are
ammonites, trilobites and
corals.
Radiometric Dating
• It is used to determined the actual
age of the rocks.
• Scientists are determining
radioactive isotopes presents in the
sedimentary rocks.
• Radioisotopes decay into
nonradioactive elements at a
constant rate.
• The rate of radioactive decay is
measured by half-life.
Half-life
It is the length of the time required for half of the radioisotopes to

24. • It is the study of how organisms
develop from fertilization to birth.
• The development of embryos,
similarities in the DNA of protein
organisms, and protein compositions
offer additional sets of indirect
evidence of evolutionary relationship.
• Embryos of different species have
similarities, especially in the later
stages of development for more closely
related animals indicating related

26. • These are body structures of different
organisms that have similar
arrangements and patterns in
embryonic development.
• Several kinds of organisms have
homologous limbs.
• These limbs have common internal
bone structures but are adapted for
different functions.

27. • They have similar appearance and
function, but they differ in origin.
• Examples are the wings of birds, bats,
and insects for flying.
• These types of wings look similar and
perform the same function, but they
possess different internal structures.
• Vestigial Organs are body parts
without specific functions and
resemble the structure of their
presumed ancestors.

28. Nucleotide and
protein sequence

29. • The sequence of nucleotides making up
DNA is also evidence of evolution.
• The theory of evolution shows that if
species evolved over time, their genes
must also have evolved.
• In these theory of evolution, genes
accumulate modifications in their
nucleotide sequence.
• Closely related species will have genes
that show more similarities in the