bio exam 4 ch 18 & 15

4.5 billion years ago

4.0 - 3.0 billion years ago

3.5 billion years ago

1.5 billion years ago

0.5 billion years ago

• disproves the belief in "spontaneous generation"
• life has to come from life

• Oparin believed the early atmosphere consisted of
• water vapor (H2O)
• hydrogen (H2)
• methane (CH4) and
• ammonia (NH3)
• but no molecular oxygen (free O2 by itself). This represented an atmosphere that contained not only the four essential elements in biochemistry but was also a "reducing atmosphere" that would favor the formation of more complex molecules necessary to form the first cells.

• proved: Inorganic molecules can react to produce small organic molecules.
• performed experiments to test whether the atmospheric conditions that Oparin suggested would allow the formation of the molecules necessary to form cells. Miller discovered that Oparin's reducing atmosphere was conducive to the formation of carbohydrates, proteins, nucleic acids, and lipids.

• 1. Atmosphere must contain sources of carbon, hydrogen, oxygen, and nitrogen. 
• 2. Large molecules (carbohydrates, lipids, proteins, and nucleic acids) must form from the smaller compounds in the atmosphere and primitive seas. 
• 3. Cell membranes must form from the large molecules. 
• 4. Genetic machinery must be installed within a cell to control replication and other cell functions. 
• 5. Eukaryotic cells must evolve from prokaryotic cells.

• 1. coacervates - first cells had lipid-based membranes as proposed by Oparin.
• 2. microspheres - first cells had protein-based membranes as proposed by Sidney Fox.

• The first cell is most likely RNA genes that are capable of replicating themselves & directing protein synthesis
• Reverse transcription could have led to DNA genes
• RNA was responsible for both DNA and protein formation
• Eventually protein synthesis would have been carried out according to the central dogma, with information flowing from DNA to RNA to protein

• Prokaryotic cells preceded eukaryotic cells. The present structure of the eukaryotic cell was formed by enfolding the cell membrane
• The mitochondria and the chloroplasts present in cells evolved from a bacteria-like organism (mitochondrion) and an alga-like organism (chloroplast) that invaded early cells and developed a favorable (mutualistic) association.

• PreCambrian
• Paleozoic
• Mesozoic
• Cenozoic

• 4.6 billion - 590 million years ago
• No multicellular creatures; marine creature dominant; origin of prokaryotes and eukaryotes

• 590 - 248 million years ago
• Dominant animals include amphibians and fish; first vascular plants

• 248 - 65 million years ago
• Dominant animals include the dinosaurs; dominant plants include conifers

• 65 million - present
• Current era; dominant animals include mammals, dominant plants include flowering plants; modern man

the changes that have transformed life on earth from its earliest beginnings to the diversity that exists today. Evolutionary biology provides a cohesiveness to nature and allows us to "make sense" of the world that surrounds us.

• the theory proposed by Charles Darwin to explain the process of evolution
• the mechanism that brings about adaptation to the environment as evolution occurs

Believed species to be fixed and permanent; living things could be arranged on a scale of complexity Scala naturae (scale of nature)

• Swedish physician and botanist
• the "father of modern taxonomy"; created a taxonomic system based on morphological (form and structure) comparisons. (kingdom, phylum, class, order, family, genus, and species)
• created binomial nomenclature and standardized the language of taxonomy through the use of Latin.
• Believed in the immutability of species, "God creates, Linnaeus arranges".

• French anatomist who developed the science of paleontology
• developed theory of catastrophism: a belief that the boundaries between various fossil assemblages could be explained by catastrophic events occurring in earth's past
• staunch opponent of evolution

• English geologist who wrote Principles of Geology,
• theory of uniformitarianism: which implied that geological processes are so uniform that their rates must balance out through time; implied an old age for the earth.
• never fully accepted idea of evolution

• theory of use and disuse, theory of inheritance of acquired characteristics (both discredited)
• Lamarck emphasized
• (1) that evolution was the best way to explain what can be observed in the fossil record
• (2) the great age of the earth
• (3) the important role the environment plays in the evolution of organisms.

Charles Darwin's grandfather who speculated about evolution as a process in Zoonomia (1794). His writings may have had some influence on his grandson's theories.

Independently developed a theory of evolution by a process nearly identical to what Darwin referred to as "natural selection".

English anatomist and physiologist; nicknamed "Darwin's Bulldog" due to his staunch defense of Darwin's view of evolution by natural selection.

Developed the theory of evolution by natural selection (gradualism); in 1859 published The Origin of Species.

Austrian monk considered the "father of Genetics" due to his research in 1865, but his research was unknown to Wallace and Darwin.

• Galapagos Islands
• off the coast of south america

• finches
• tortoises

Alfred Russell Wallace

• (1) Population tend to exhibit exponential growth; there is a tremendous potential in nature for overproduction of offspring. 
• (2) Resources needed for survival are limited in nature, which leads to a struggle for survival.
• (3) Individuals within populations vary. Some of these variations are more or less
• advantageous in the struggle for existence. 
• (4) The individuals with the best combination of characteristics will survive ("survival of the fittest"). 
• (5) The survivors will have an opportunity to reproduce and pass the characteristics that gave them the survival edge on to their offspring.

fitness: is the relative reproductive success of an individual (Barney Fife who has 5 kids is more fit than The Rock who has 0)

Change that helps a species become more suited to its environment

English Pepper Moths - example of natural selection; darker moths were selected for survival as the industrial revolution wore on and pollution became more pronounced

• fossil record
• biogeography
• taxonomy
• comparative anatomy
• comparative embryology
• molecular biology (biochemistry)

remains or evidence of some organism that lived long ago

are a common ancestor for two different groups of organisms

the distribution patterns of organisms

classification which implies descent

• homologous organs and structures
• vestigial structures

parts of organisms that exhibit similar basic structures and embryonic origins

parts of organisms that are similar in function only

remnant of a structure that was functional in some ancestor but is no longer functional in the organism in question

• All vertebrate embryos have:
• A postanal tail
• Paired pharyngeal (gill) pouches

• All living organisms:
• 1. Use the same basic biochemical molecules
• 2. Utilize same DNA triplet code
• 3. Utilize same 20 amino acids in their proteins
• DNA base-sequence differences: (cytochrome c)
• When very similar, suggest recent common descent
• When more different, suggest more ancient common descent