Title: EVOLUTION
Subtitle: Only here, it seems.
Theme: The puzzle of biodiversity
Evolution tends to face skepticism, with some views considered outrageous.
Emphasis on evidence in science rather than belief.
Importance of evolution in understanding life.
Quote from Theodosius Dobzansky: "Nothing makes sense in biology except in the light of evolution."
Evolution defined as:
Descent with modification
Changes in allele frequencies across generations.
Fundamental property of populations and species.
Charles Darwin:
Born in 1809 to a wealthy British family.
Briefly studied medicine at Edinburgh.
Attended Cambridge for ministry studies.
Developed an interest in beetle collection.
Served as the ship's naturalist on HMS Beagle starting in 1831, which established his scientific reputation.
Reference to Darwin's status in 1840 as depicted in Price 1996's publication.
After returning from the voyage, Darwin was unwell but wealthy.
Noticed geographic variations and organism similarities within regions.
Struggled to comprehend adaptation until reading Malthus in 1838, which inspired the natural selection concept.
Wrote a secret essay in 1844 detailing his thoughts.
Recognized as a prominent figure parallel to Darwin in discussing natural selection.
Wallace worked in regions such as Indonesia and Malaysia.
In June 1858, Wallace shared his manuscript outlining natural selection with Darwin.
Both presented their findings to a major scientific society in London.
In 1859, Darwin published "Origin of Species":
Documented evidence for evolution.
Explained natural selection as the primary mechanism for adaptation.
Evolution quickly gained acceptance among scientists.
Natural selection faced skepticism until Mendel's genetics were integrated into evolutionary theory.
Evidence for evolution in contrast to the belief of "special creation" (supernatural origins).
Homologous similarities:
Traits shared among organisms due to common ancestry, inherited through descent.
Different from convergent functional similarities.
Similar limb structures in tetrapod vertebrates (e.g., humerus, radius, ulna) exist despite different functions.
Molecular characteristics also show sets of homologies.
Vestigial organs are features that have reduced function but are shared with ancestors.
Examples include the pelvic girdles in snakes and whales.
Also noted are molecular vestiges.
Transitional fossils demonstrate the hind limb loss in ancient marine mammals:
Indohyus, Pakicetus, Ambulocetus, Basilosaurus, Bowhead whale.
Key structures include tibia, femur, pelvis.
Importance emphasized by Darwin and Wallace:
Related species often found in close geographical proximity, such as Galapagos birds.
Strata fossils show progression and similarity with adjacent layers, supporting descent with modification.
Observance of niche similarities in placental mammals versus Australian marsupials (e.g., different burrowers and climbers).
Highlight of convergent evolution reflected in ecosystem adaptations.
Real-time observations of evolution:
Examples include Peppered moths, Darwin’s finches, and sticklebacks.
Phenotype variations observed in Gasterosteus aculeatus, changes correlating with environmental factors noted.
Rapid evolution of armor in specific populations of sticklebacks observed over time.
Frequency data showing the shift in morph types during the observation period.
Increases in antibiotic resistance correlated with the frequency of antibiotic use in Finland.
Highlighted by the rise in infections among middle ear bacteria with increased beta-lactam usage.
Artificial selection examples presented by Darwin:
Breeders influencing traits in dogs, cabbages, and pigeons.
Insights into speciation observed experimentally in controlled conditions.