EVIDENCES
OF EVOLUTION
MELC: EXPLAIN HOW FOSSIL RECORDS, COMPARATIVE ANATOMY,
EMBRYONIC DEVELOPMENT AND GENETIC INFORMATION PROVIDE
EVIDENCE FOR EVOLUTON
EVOLUTIO
N
Evolution is a change in inherited traits
within a population across generations.
Small variations can be passed over
generations.
And today, significant evidences for evolution will provide us
information on how fantastic diversity like these happens.
EVIDENCES OF EVOLUTION
• Fossil records (direct evidence)
(Indirect Evidence)
• Comparative Anatomy
• Embryonic Development
• Genetic Information
1. FOSSIL RECORDS
FOSSILS are example of evidence that paleontologists use in studying
evolution. Paleontologist is a person who studies fossils.
They are preserved physical remains of organisms that lived in the past.
Remains include bones, shells, teeth and feces.
Most fossils were commonly found in sedimentary rocks.
FOSSIL FORMATION
MAIN TYPES OF FOSSILS
• Compression or Body Fossils
Fossils of animals or plants tissues preserved in sedimentary rocks and
is formed with more organic material. Bones, teeth and woody stem.
Icthyosaur skull
Megalodon Shark tooth
Fossil of Pre-historic plant
Impression or Trace fossils
Are preserved marks of activity left behind by an organism when it was
still alive. This can be a footprint, feces (coprolite), burrow or even the
imprint of an ancient plant.
Trace of a prehistoric animal
Plant imprint
Dinosaur footprint
Determining the age of fossils
• Relative Dating
The age of rock is compared to the other rock layers. The younger
sedimentary rock are assumed to be on top and the older found at the
bottom. FOSSILS (bottom)-older; FOSSILS (top)-younger
• Radiometric Dating
Method used to determine the age of rocks using the decay of
radioactive isotopes present in rocks.
All organisms have decaying carbon-14 in their body. Carbon dating used
to tell the age of organic materials.
A. PIECES OF THE PAST
2. COMPARATIVE ANATOMY
• Study of the similarities and differences in the structures of different
species.
• THREE TYPES OF STRUCTURES: Homologous structures, Analogous
structures, Vestigial structures
HOMOLOGOUS STRUCTURE
Structures found in
organism that are related.
They share similar
structure but with different
functions.
DIVERGENT EVOLUTION
Splitting ancestral population into two or more subpopulations that are
geographically isolated from one another.
ANALOGOUS STRUCTURE
• Structures found in
organisms that are not
related. They share
similar structure and
similar function.
• CONVERGENT EVOLUTION
Increase in similarities among species derived from different ancestors as
a result of similar adaptation to similar environment.
VESTIGIAL STRUCTURE
• Organs and body parts that are “left over” from evolution. Structure no
longer have the same function from their previous ancestors as they
may have reduced size because they are no longer used.
D. SQUADMATES OR NOT
C. EMBRYONIC DEVELOPMENT
• Is the study of the similarities and differences in the embryos of
different species. It is valuable to compare organisms in the
embryonic stage.
C. EMBRYO ON THE GO
1.
2.
3.
4.
CHICKEN
FISH
HUMAN
TORTOISE
4.GENETIC INFORMATION
• Small mutations or changes in DNA eventually lead to the evolution of
new species. Amino acid in organisms determine their degree of
similarities.
• Scientists believed that the greater the similarity in amino acid
sequence, the more closely related they are in the evolutionary sense.
D. WHERE DID I GO WRONG?
EVIDENCES
OF
EVOLUTION
FOSSIL
EVIDENCE
BODY
COMPARATIVE
ANATOMY
EMBRYONIC
DEVELOPMENT
GENETIC
INFORMATION
TRACE
AMINO ACID
HOMOLOGOUS
ANALOGOUS
VESTIGIAL
EMBRYO