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THEORY OF EVOLUTION. CHANGE OVER TIME. BIOGENESIS / ABIOGENESIS. ALL LIFE COMES FROM PRE-EXISTING LIFE. LIFE COMES FROM NON-LIVING THINGS. SPONTATEOUS GENERATION. REDI / PASTEUR. FLY AND MEAT EXPERIMENT SWAN-NECKED FLASK EXPERIMENT. EARLY EARTH’S ATMOSPHERE. HOT
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THEORY OF EVOLUTION CHANGE OVER TIME
BIOGENESIS / ABIOGENESIS • ALL LIFE COMES FROM PRE-EXISTING LIFE. • LIFE COMES FROM NON-LIVING THINGS. • SPONTATEOUS GENERATION
REDI / PASTEUR • FLY AND MEAT EXPERIMENT • SWAN-NECKED FLASK EXPERIMENT
EARLY EARTH’S ATMOSPHERE • HOT • CO2, CO, N2, H2S, H2O – NO FREE O2
MILLER AND UREY • TESTED THE ORIGIN OF LIFE THEORY IN THE LAB.
1ST DEVELOPED ORGANISM • ANAEROBIC (NO OXYGEN) AND PROKARYOTIC ( NO NUCLEUS, BACTERIA)
History • Darwin’s World (1809 - 1875) • Height of the British colonial period. • Beginning of the Industrial Revolution. • New Ideas: • Taxonomy of Carolus Linnaeus • Lyell’s “Principles of Geology”
Binomial System of Nomenclature Carolus Linnaeus (1707 – 1778) Believed in the “Fixity of Species”
Charles Lyell • Father of Geology
Charles Lyell’s view of the process of formation of sedimentary rock
Suggests that sedimentary rock is very old – therefore the species that are represented in this rock must also be old. • Most fossils are found in sedimentary rock. • Older fossils will be found below younger fossils.
Charles Darwin At the age of 22, he joined a 5 year expedition aboard the HMS Beagle to map the coast of South America
http://evolution.berkeley.edu/evolibrary/home.php www.darwinday.org/englishL/life/beagle.html www.darwinday.org/englishL/life/beagle.ht Used by permission of Darwin Day Celebration (at DarwinDay.org), 2006 I have called this principle, by whicheach slight variation, if useful, is preserved, by the term Natural Selection. —Charles Darwin from "The Origin of Species"
Darwin described his theory in the form of a long essay which he called “On the Origin of Species”.
Charles Darwin At age 50 (1859) At age 65 (1874)
Through his observations made in the Galapagos Islands, Charles Darwin formulated a theory of how species change over time, called natural selection.
Evolution • A change in successive generations of organisms, due to random mutation and changes in the organisms’ surroundings
The evidence for evolution is drawn from a variety of sources of data, including: • the fossil record, • radiometric dating, • genetic information, • the distribution of organisms, • anatomical and developmental similarities across species.
EVIDENCE OF EVOLUTION • STRUCTURAL ADAPTATIONS • MIMICRY • CAMOUFLAGE
EVIDENCE OF EVOLUTION • STRUCTURAL ADAPTATIONS • MIMICRY • CAMOUFLAGE • MILLIONS OF YEARS • PHYSIOLOGICAL ADAPTATIONS • CHANGE IN A METABOLIC PROCESS • WHAT DO YOU HEAR ABOUT IN THE NEWS ABOUT SOME BACTERIA?
EVIDENCE FOR EVOLUTION • 1. THE FOSSIL RECORD
Fossil Record • Although there is not a complete record of ancient life for the past 3.5 billion years, a great deal of modern knowledge about the history of life comes from the fossil record.
The study of fossils provides strong evidence for evolution. Petrified Trees Hominid skulls
Fossilized organic matter in a leaf Ammonite casts
“Ice Man” Scorpion in amber
EVIDENCE CONT. • 2. BIOCHEMICAL / DNA ANALYSIS
EVIDENCE CONT. • 3. EMBRYOLOGY
Developmental Similarities • Many species have very similar embryonic development. • The embryo of a chicken, a pig, and a fish are almost identical at certain points in their development.
EVIDENCE CONT. • 4. SHARED ANATOMICAL STRUCTURES • HOMOLOGOUS STRUCTURES – SAME STRUCTURE, DIFFERENT FUNCTION – SUGGEST COMMON ANCESTOR
Homologous Structures • Body parts in different organisms that have similar bones and similar arrangements of muscles, blood vessels, and nerves and undergo similar embryological development, but do not necessarily serve the same function; e.g., the flipper of a whale and the forelimb of a horse.
Homologous Structures Human Cat Whale Bat
VESTIGIAL STRUCTURES – REDUCED IN SIZE, NO LONGER USED • EX. APPENDIX, WISDOM TEETH, COCCYX
Vestigial Structures • Features that apparently serve no function in an organism and are allegedly holdovers from an evolutionary past. Such features, though no longer useful, are presumed to have been useful in ancestral species.
EX.: appendix in humans, whale pelvis, tiny snake pelvic and limb bones, and the eyes in cave-dwelling salamanders and fish that are completely blind.
5. Distribution of species • Most marsupials live in Australia • This supports the theory of continental drift.
Species • Organisms that can breed and produce FERTILE offspring.
CHARLES DARWIN • FATHER OF EVOLUTION
Natural Selection • Organisms with certain genetic variations will be favored to survive and pass their variations on to the next generation.
NATURAL SELECTION • 1. INDIVIDUALS DIFFER AND SOME OF THE VARIATIONS ARE HERITABLE
Charles Darwin’s Theory of Evolution: Members of a population have heritable variations.(Inheritance of traits)
Individuals of a population exhibit a range of variations in a trait as a result of the variations in their genetic codes.