Download Evidences of Evolution

Evidences of Evolution
Presented By: Mr. Godinez
Evolution is
• Genetic change in
a population
through time
Evidence of Evolution
• Evidence for evolution are grouped into four main
catagories:
• Biochemical
• Fossil Record
• Comparative Anatomy
• Observable Events
OBSERVABLE EVENTS
• Some changes in species have been observed and studied:
• Observable events show that evolution is an ongoing
process
Peter & Rosemary
Grant’s Study of
Beak Size Shift in
Darwin’s Finches
H. Kettlewell’s Study
of Peppered Moth
Color Shifts
Fossil Record
• Paleontology- study of fossils
• Fossil- remains or traces of an organism that lived long
ago
• Remains:
• Bone, tooth, or shell
• Traces:
• Burrow, footprint or imprint
COMPARATIVE ANATOMY
• HOMOLOGOUS STRUCTURES
• structures with similar structure but different
function
• limbs of vertebrates
• (human, horse, cat, bat)
• Similar genes
• Descent from a common ancestor
COMPARATIVE ANATOMY
• VESTIGIAL STRUCTURES
• organs so reduced in size that they are
nonfunctioning remnants of similar
organs in other species
• human tailbone, appendix, whale pelvis
• an organism’s evolutionary past
• a common ancestor with species that
have similar structures that are still
functioning
COMPARATIVE ANATOMY
• EMBRYOLOGY
• Embryos of different species may appear similar
in early stages of development
• ex: vertebrate development
• Comparison of similarities in
embryos can show:
• Relationship to a common
ancestor
Fossil Record
• Most fossils are found in layered
sedimentary rock
• Oldest fossils are on the lowest
layer
• Comparing fossils from different
layers shows:
• Life on Earth has changed
• Increased number of life forms
Biochemical
• The Genetic Code
• Triplets of DNA nucleotides
sequences that code for specific
amino acids
• a.a. triplet is the same in almost all
organisms
• Demonstrates there is a probable
common ancestor for all life on Earth
Biochemical
• “Universal” Genetic Code
• Similar genes
• Overt he ages, the genetic code has passed unchanged
(mostly) from parent to offspring.
BIOCHEMICAL
• AMINO ACID SEQUENCING
• The amino acid
sequence in a
particular protein
is compared
between
organisms.
45
27
67
1
Number of differences
from human hemoglobin
Biochemical
• Comparing a.a. sequence shows:
• a.a. sequencing is probably the Strongest evidence for relationships
among organisms.
Amino Acid Differences in Hemoglobin Compared with Human
Species
Differences
Gorilla
1
Rhesus Monkey
8
Mouse
27
Chicken
45f
Frog
67
Lamprey
125
BIOCHEMICAL
• CLADOGRAM: diagram that
shows the evolutionary
relationship among a group of
organisms.
B
A
Where
would the
What organism
common
belongs
at each
ancestor
be?
branch?
D
E
F
G
10 0
20
30
50 40
Common
ancestor
100
150
C
Number of Amino Acid Differences
Conclusion
• Darwin argued that living things have been
evolving on Earth for millions of years.
• Evidence for this process could be found in:
• the fossil record
• the geographical distribution of living species
• homologous structures of living organisms
• similarities in early development, or embryology.
Works Cited
• “Geographic Distribution of Organisms” photo: Miller, Kenneth and Levine,
Joseph. (2004). Biology. Prentice Hall.