Evolution Chapter 1 Notes

Chapter 1 Notes: Darwin and the Beagle Evolutionary View of Life (6 major principles/concepts/ideas) 1) Reproductive continuity of all life forms.  Living things have flesh, blood, relatives, and parents.  Humans, chimpanzees, dinosaurs, birds, fish, amphibians, fungi, plants.  Life has been evolving over the course of billions of years.  All life forms can trace their reproductive continuity all the way back to billions of years ago where all life forms have ancestors who were bacteria (prokaryotic cells).  There is no discontinuity (no break) in this cycle.  All life forms are produced by either asexual or sexual reproduction. 2) Species arise from earlier forms and change over time (become remodeled).  Give rise to descendants that will not be exact replicas of them.  Inherent mechanisms are associated with sexual reproduction. 3) Species share common ancestors.  Humans would share a common ancestor with chimpanzees (our relatives/cousins) more than they would with monkeys.  The common ancestor (chimp like) between humans and chimpanzees comes from roughly the 5–6-million-year time frame.  Go back about 25-26 million years to find the common ancestor shred between humans and monkeys.  Birds – modified descendants of dinosaurs.  Mammals – related to dinosaurs; share common ancestors in the reptilian ancestry.  Mammals & Dinosaurs – come onto the Earth roughly about the same period 200-220 million years ago; descendants of reptiles.  Reptiles – descendants of amphibians.  Amphibians – descendants of fish.  Fish – have invertebrate ancestors.  Humans are related to turtles; more distantly; go back about 300 million years ago for a common ancestor. 4) Earth is 4.6 billion years old. 5) Earth’s surface changes with time.  Inhabitants evolve and change.  Impacted by weathering, rain, temperature changes, wind.  Broken up into tectonic plates; move around slowly; causes volcanism, earthquakes, tsunamis.  Lush forest – over time becomes drier evolving into a desert region. 6) Imperfections indicate a historical process.  All living things have a history of existence. Fact and Theory (Evolution is both)

1) Factual Side.  Fact – truth; reality; actuality; certainty.  There’s been change over the course of time; triceratops fossil is the tangible proof.  Dinosaurs previously existed; about 65-220 million years ago. 2) Theoretical Side.  Theory – explanation based upon scientific evidence; not guesses.  Trying to explain what’s driving the change; what led to the extinction of dinosaurs/what led to the origin of dinosaurs?  Try to explain the facts/explain a variety of phenomena.  Dinosaurs – extinct 65 million years ago because of a meteorite. Intelligent Design Theory (Religious philosophy)  Modified descendant of creationism.  Creationists – biblical literalists; take the Bible literally. 1) Is a pseudoscientific argument for the existence of God. 2) Proposes that certain characteristics of living organisms are best explained by an intelligent cause. 3) Is an anti-evolutionary perspective that does not accept that life forms have common ancestors and are the modified descendants of previously existing life forms.  Does not accept that humans and chimpanzees share a common genetic pool/DNA (98.5%) about 5-6 million years ago. 4) Is a form of creationism that lacks empirical evidence and offers no testable hypotheses; ID theory is NOT science!  No experimentation.  No verifiable evidence.  No observations through experimentation.  No experimental results. 5) Proposes that certain biological and informational characteristics of life are too complex to be the result of evolution.  Their problem is that they don’t understand enough about evolutionary biology. 6) Avoids identifying the intelligent designer, but proponents have said the designer is the Christian God. Human Body Imperfections (Human Phenotypic Oddities) 1) Coccyx Bone.  Small, fused vertebrae.  A vestigial tailbone; humans had ancestors that had tails.  25 million years ago humans and monkeys shared a common ancestor.  Humans have a gene called pseudogenes; leftover from our past. 2) Wisdom Teeth.  Clue to an evolutionary process.  Humans get them removed because there isn’t enough space in the jaw; ones cranium expanded while the size of the face shrunk.