- Linnaeus - collected, classified plants and animals.

- His Two Kingdoms (Plantae and Animalia)

- Classification based on morphology and structure of the body.

- Generic name (Genus) represents the general group (all dog-like animals)

- Specific name (Species) represents the more restricted classification - a group of organisms having structural, functional, and developmental similarities and that are able to interbreed and produce fertile offspring.

- Other groupings of organisms include Phylum, Class, Order, and Family (KPCOFGS)

Rules for naming organisms
- Only one genus name allowed per Kingdom.
- Latin or Latinized names. (example: Tribbilus picardii)

- Now generally thought to be Five Kingdoms: Plantae, Animalia, Protista, Monera, Fungi
(or maybe as many as 7 or 8 kingdoms…)
 
 
 
 

Evolution of Living Things:  Separating Fact (Observation) & Theory (Explanation).
 
 
 

Evolution is genetic change among a population of organisms through time.
Or as Darwin put it, "Descent with modification."
 
 
 

- Evolution is a scientific observation, a fact.  Evolution occurs among populations of all Kingdoms in nature and in scientific laboratories with controlled experiments.
 
 
 

- Evidence in form of: embryology, comparative anatomy, geographic distribution of organisms.
 
 
 

- From the paleontological record, it is apparent that evolution has occurred in virtually all groups of organisms studied.
 
 
 

- Organisms all contain genetic code: it controls their development and is passed along to offspring. Mostly this is in Deoxyribonucleic acid (DNA).
 
 
 
 

The next question is What drives evolution?  What factors drive evolutionary trends?

Georges de Buffon (French)

- defined the species as being reproductively isolated and FIXED, UNCHANGING.

- recognized that organism character is closely related to its environment.

- stated that modifications of organisms are due to inheritance of characters and changes caused by environment.

- Not exactly a theory of evolution, because it does not explain How New Characters Arise.
 
 

Erasmus Darwin (Chuck's Grandfather)

- believed that Protection and Sex were the two most important characters.

- Lust and various Weapons and Ornamentation for sexual competitiveness have obvious value in creating Reproductive Fitness.

- Protection (Self Preservation) was merely important in getting to be sexually mature.

- Also not a full fledged theory.
 
 

Jean Baptiste de Lamarck - book in 1809 - Inheritance of Acquired Characteristics.

- Observed that organisms acquired useful adaptations and passed these adaptations down through successive generations.

- Theorized that new features in organisms appear because changes in the environment cause some Needs of the organism to develop.  These Needs bred Habits and Habits developed into Characters.  If both parents possessed these Characters then they were passed on in some fashion to offspring.

- The giraffe's neck for example....
 
 
 
 
 
 

- Doesn't work at all.  A blacksmith develops big arms by hammering, but his/her offspring do not necessarily have big strong arms.

- No mechanism exists to pass acquired characters on to future generations.

- In essence, theory suggests that evolution is directed toward some planned goal - more refined beings, perhaps?

- In one famous experiment, 200 generations of mice.
 
 
 
 
 
 

Evolution is genetic change among a population of organisms through time.
 
 

Population is a group of organisms that is free of barriers to reproduction.  Can freely interbreed.
 

Gene Pool is the total genetic code of a population of organisms.
 
 
 

Ecological Niche is a specific habitat within a larger ecosystem.
 
 
 

Charles Darwin - Observed that populations exhibit Variation.
Observation: Galapagos Islands Finches - Bill shape.

Proposed:  early finch colonists from S. America adapted to fit different ecological niches on G.I.
 
 

Darwin proposed that
1)  Populations exhibit natural variability.
 

2)  Some variations more favorable for survival.
 

3)  Not all offspring survive to reproductive maturity.
 

4)  Offspring with favorable variations are more likely to survive.
 

This is Natural Selection.
 
 

Example: Natural Selection and the Giraffe
- forms with longer necks had greater survival potential, hence greater reproductive success.
 
 
 
 
 

Example: Pepper moths in Birmingham, England.

- Dark gray moths on East side of city (downwind of coal stacks)

- Buff yellow on west side.

- Yellow eaten on dark side, gray eaten on far side.
 
 
 
 

** Still a perceived problem:  not enough natural variation in most populations to create totally new creatures from old ones.  Giraffe, whales, etc.  (We'll fix this "problem" in a little bit.... )
 
 
 
 
 

Scientific Creationism - "all basic types of living things, including man, were made by a direct creative act of God during the creation week described in Genesis."

- current Creationist movement promotes the:

Young-Age Earth Model   versus the "traditional"  Old-Age Earth Model
 
 

Young-Age Earth Model says All Geologic Events did occur, but within the last 6000 years or so....
 

their evidence?  scant....  for example:
1)  Bioturbation?
Old-Age ::  bioturbated for slow, gradual sedimentation.
Young-Age ::  laminated sediments argue for rapid flooding.
Claim:: sedimentary rocks are mostly laminated.
Data:: most marine sedimentary rocks are highly burrowed
 
 
 
 
 

 2)  "Missing Links"? in evolutionary chain....
Old-Age ::  gradual evolution, must be links
Young-Age ::  no evolution, therefore no links.
Claim:: gaps in the fossil record abound, therefore!
Data:: instances of intermediate species abound in the fossil record.
 
 
 
 
 
 

Creationists almost solely look for the big jumps, ignoring the little ones
 

for example: Archeopteryx is a fascinating mix of bird & dinosaur features - where are the "Real Intermediates"?
 
 

Creationists' geological support of both claims (and others) are fuzzy, with very little data presented.  Tendency to present one side of the hypothesis (their side).
 
 
 

Science: a human activity aimed at developing a body of knowledge.
 

(note - this is a very broad definition of science.)
 

Empirical Science - science based on observations.  Theories are testable by prediction and observation, leading to support or falsification.

Belief Science - science based on belief.  Theories are based in belief and commonly supported by reports of supernatural phenomena, not empirically testable.  Also called Pseudoscience.
 
 

Empirical Science	Belief Science
Chemistry	Alchemy
Astronomy	Astrology
Mathematics	Numerology
Psychology	Parapsychology
Logic	Theology

 
 

Definition? Testable?  No -- Creation Science is Belief Science, not Empirical Science.
 
 
 

Is there a "conflict" between Science and Religion?
 
 
 
 

- isolation leads to a reduction in the gene pool size.

- genetic changes in the population spread quickly through the new smaller gene pool.

- when reproductive isolation is complete, a new species has developed.
 
 
 

How to become Reproductively Isolated
1)  Geographic Barriers:
- continental drift separates populations
 
- rising sea level divides populations

- island populations are physically isolated -

- mountain building separates two populations

- river system migrates or grows dramatically
 
 
 

Small populations are called peripheral isolates.
 
 
 

 2) Reproductive Barriers:
- societal factors
 

 different mating rituals - elaborate displays
 

 different behaviors - day/night, fruit
 

- physiological factors
 

   incompatibility - different body sizes
 

   uglification - (sorry, that's my word) changes in body form that limit the attractiveness to potential mates
 
 
 

Phylogeny is the evolutionary history of a species.   How do populations evolve?  Gradually? In steps?
 

Two models:
1) Phyletic Gradualism - evolution occurs gradually, incrementally, over long periods of time.
- Diagram of Morphological Change versus time.  Use diagonal line trees from a single stem.
 
 
 
 
 
 
 
 

2) Punctuated Equilibrium - evolution can occur very rapidly and then undergo stasis.  Developed by Eldridge and Gould based on the fossil record.
- Diagram of Morphological Change versus time.
 
 
 
 
 
 
 
 
 

Divergent Evolution - a single lineage develops new features that diverge in morphology from the original.  Adaptive radiation to fill new ecologic niches.  Darwin's Finches.
 
 
 
 
 
 
 
 
 
 

Convergent Evolution - two or more lineages that are distantly related develop morphological similarities, sometimes competing for similar ecologic niches.  Australian marsupials versus placental mammals of other continents.  Brachiopods versus Clams.
 
 
 
 
 
 
 
 
 

The Modern Synthesis - modern genetics and natural selection combined into a modern view of evolutionary process.

Genes: basic unit of character inheritance

 - found on chromosomes in cell nucleus

 - made of DNA
 

Mutations: physical/chemical change in genes

 - leads to different character from original
 
 

Only mutations of sex cells count in evolution

- must pass trait on to future generations.

- mutations in regular cells would be Lamarkian evolution (doesn't work).
 
 

Mutations are random - benign, harmful or useful.

Useful - extremely rare.

Harmful - probably most common, not passed on to descendents very well (don't survive to reproduce).

Benign may or may not be passed along.
 
 

Modern Synthesis - Origin of variability in nature.

- remember the problem??
 
 
 
 

- Useful mutations + natural selection  = modern view of evolutionary process.
 

1) Useful mutations provide benefit to individual
 

2) Leading to enhanced reproductive success
 

3) Gradual shift of gene pool toward this new character.
 
 

Modern synthesis may explain why both gradualistic and punctualistic models of evolution coexist...
 

- major useful mutations are very rare, but lead to significant and rapid changes in gene pool.