What did the article say was the evolutionary significance of women living a longer life?

Evolution and Natural Selection

A change in the characteristics (genes) in a population over time Evolution is... A change in the characteristics (genes) in a population over time

Evidence Fossils Anatomy Development Biological molecules

Fossils Fossils are preserved or mineralized remains or imprints of an organism that lived long ago Conditions must be perfect for fossils to form Rapidly buried – before it decays or is eaten Covered in fine sediments carried by wind, water, or volcanoes *Hard body parts are more likely to become a fossil than soft body parts

Fossils Fish Amphibians Reptiles Birds Reptiles Mammals Examples: Trilobites, dinosaurs, plants, insects, skulls Transition fossils include Fish Amphibians Reptiles Birds Reptiles Mammals Land mammals Whales

Anatomy Similarity in body structure in different animals Vestigial structures – Structures found in organisms that are reduced when compared to other related organisms (ex. appendix, human hair, whale hind limbs) Homologous structures – structures that share a common ancestor

Comparative Anatomy of Primates

Development Embryos look similar in dissimilar organisms All vertebrates have a tail during development (including humans) All vertebrates have a pharyngeal pouch (turn into gills in fish and in humans they turn into structures in the throat)

Biological molecules All living organisms have DNA (nucleic acids) and share the same or a similar genetic code The sequences that make-up proteins are more similar in closer related species

Species Amino Acid Differences from Human Hemoglobin Protein Gorilla 1 Rhesus monkey 8 Mouse 27 Chicken 45 Frog 67 Lamprey 125

Evolution is a Scientific Theory! A scientific theory is not a guess A theory is… A broad explanation that ties together a great number of observations It makes predictions that can be tested Must be supported by a vast accumulation of evidence Acts as a framework for thinking about the natural world *Other theories include, the theory of universal gravitation, and the theory of magnetism

The beginning of the idea “Decent with Modification” Carolus Linnaeus (1707-1778) – Sought to classify (organize) life’s diversity James Hutton (1726-1797) – Geologist that proposed that geological process are gradual and are unchanging Charles Lyell (1797-1875) – Uniformitarianism – mechanisms of change are constant over time Lamarck (1744-1829) - gradual evolutionary change – but he was wrong that organisms cannot inherit acquired characteristics.

Charles Darwin Naturalist Studied organisms and traveled the world on the Beagle Not really interested in shaking the world – delayed publication of his work until Alfred Wallace came up with the same idea

Studied finches on the Galapagos Islands Finches looked similar on all the islands Different variations of beaks were observed Helped Darwin come up with the idea of natural selection

What Darwin Observed Variability Heritability Individuals within a species are different (ex. Look at the differences between human individuals) *Genes are responsible for the variation Heritability Traits are passed down to offspring

What Darwin Observed Competition Animals compete to survive Unequal survival and reproductive success The more fit individuals in their environment will survive and reproduce

Darwin Proposed a Mechanism for Evolution Definition of Natural Selection Individuals that have physical or behavioral traits that better suit their environment are more likely to survive and will reproduce more successfully than those that do not have such traits.

Examples of natural selection

Examples of Natural Selection

Evolution of new species… Reproductive Isolation As the two populations become more and more different, they eventually become unable to breed with one another successfully. A new subspecies and eventually species form. Kaibab squirrel on North Rim of Grand Canyon Abert squirrel on South Rim of Grand Canyon .

http://video.google.com/videoplay?docid=7293185927768983820# Think about how natural selection is shaping these situations Natural selection cannot create perfect forms, but rather works by tinkering with the original form. How do these examples support this statement?