BIOL 1001 Midterm 1 Alex Mills Feb/1/2014
Science 3 Key Methods
-Hypothesis: Is a tentative answer to a well framed question.
Proposed explanation on the basis of limited evidence as a
starting point for further investigation.
Is an explanation on trial, making a prediction that can
- The competitive part of the experiment is called the control and the experimental
part is called the treatment.
2. Descriptive Science or Discovery Science
- Careful measurement and observation (empiricism)
- Mensurative Experiments (without manipulation)
- Focus on describing but still with goal of explaining.
3. Model Building
- Models are representations of ideas, structures or processes.
1. Factors are in pairs.
2. When 2 different factors for a character are in an individual, one factor is dominant.
3. When the organism makes gametes, the factor segregate randomly so that each has a
50% chance of being in a particular gamete.
(Mendel had no knowledge of chromosomes or of meiosis) Scientific Method
1. Hypothesis generation
- Experiment using controls
- Collection of Data
- Analysis of Data
3. Creating models that help us think about how things work, yielding ideas for tests.
A Scientific theory is much broader than a hypothesis. Meant more as a theorem rather than a
theory. Scientific theory's are
- Broad in scope
- General enough to generate a new hypothesis
- Supported by a large body of evidence
(continually tested and found not to fail)
- Not merely an idea (not like a hypothesis)
Definitions you need to know!
Haploid: A cell with one copy of each chromosome (in most vertebrates this is only in sperm and
egg cells (gametes)).
Diploid: A cell with two copies of each chromosome (homologous pairs) (Most body cells in
vertebrates "somatic cells").
Homozygous: Both alleles for a gene are the same.
Heterozygous: The two alleles for a gene are different.
Genotype: The genetic makeup or set of alleles of an individual organism.
Phenotype: The visible or otherwise measurable characteristic (physical or behavioural) of an
individual organism resulting from genetic and environmental influences. Population: A group of interbreeding individuals living in a spatially defined area.
Gene Pool: The aggregate of genes in a population at any one time.
- All the alleles...
-... at all gene loci...
-... in all individuals...
-...in the population...
Alleles: - One of two or more alternative forms of a gene that arise by mutation
and are found at the same place on a chromosome.
- One member of a pair (or any of the series) of genes occupying a specific spot
on a chromosome (called locus) that controls the same trait.
Allele frequency: This is a measurement that determines how frequent the allele expression of
a particular gene arises in a population. The result should be in
close correlation with the laws of natural selection, where more
favourable alleles should become dominant in a species over time, or
are present due to a niche environment where
a particular allele would prove advantageous.
Chromosome: A threadlike structure of nucleic acids and protein found in the nucleus of
most living cells, carrying genetic information in the form of genes.
Lecture 1 Developing Ideas about Evolution
Theory of Special Creation
- Supernatural creator
- Young Earth (biblical)
- Typological Thinking
- Hierarchy is a ladder
Theory of Evolution
- Natural process
- Old Earth (geological)
- Species change (dynamic)
- Population Thinking
- No such thing as higher and lower species
Charles Darwin (1809 - 1882)
o Graduated with a degree in theology
o Dropped out of medicine
- First job: Captain’s companion on a royal expedition to South America coastline.
- Main goal: His main goal was to chart the waters of the South American coastline.
- Charles Darwin’s own term for Evolution
o “Evolution” was used more by other advocates who followed
Articulated the mechanism: Natural Selection Origin of Species
1. Evidence that the many species of organisms currently in existence are descendants of
different and now extinct ancestral species (i.e. Descent with Modification)
2. Mechanism of Evolution: Natural Selection (Lecture 4)
- Pre 1859: Exclusively a belief in God centered Creation
- Post 1859: Descent with modification through natural processes
- Actually: Ideas of Evolution pre-dated Origin of Species
1. Philosophical Culture
o Age of Enlightenment ~ Age of Reason (Europe: 1600 – 1800)
o A belief that the material world could be deciphered with logical thought and
observation / measurement
o Resists hegemony of religions
o More emphasis on Individualism
- Charles Darwin’s grandfather
- Was a physician and Poet (The Temple of Nature (famous work))
2. European Imperialism
o Europeans were travelling everywhere and were documenting what they were
finding and experiencing.
Alfred Russell Wallace (1823 – 1913)
- Middle class (unlike Darwin)
- Co-discoverer of “natural selection”
o Artificial Selection
When humans have intentionally modified other species over many
generations by selecting and breeding individuals with desired traits.
o Uniformitarianism was promoted by Charles Lyell (Darwin’s friend) in
Principles of Geology 1830. 5. Paleontology
o Study of fossils
• Remains or traces of organisms from the past
• Mostly in sedimentary rocks
• Formed in rock generated from ancient sand and mud that settle
to the bottom of the seas, lakes, marshes
• Rock layers are called strata (singular, stratum)
• Parts are later exposed by erosion by quarrying
o Georges Cuvier
• First to extensively document extinct organisms
• Labelled an earlier era as an “age of reptiles”
• Associated with the eventual widespread acceptance of
• Articulated a Principle of Correlation of Parts (1798)
• Megatherium (Extinct Mammal)
• Mosasaur (Extinct Reptile)
• Pterodactyl (Extinct Reptile)
Fundamental Cuvier Principles
1. The deeper (i.e. older) the strata, the more dissimilar the
fossils are from current life.
2. Moving upwards, certain species disappear and new ones
Was not an evolutionist
World’s foremost anatomist, he could not believe in changing forms
Was a catastrophist, believed extinctions were due things like volcanos
o Mary Anning (another great Paleontologist)
One of the greatest fossil hunters of the 1800s. Was excluded from the
corridors of scientific power because she was a female. Jean Baptiste de Lamarck
- Contemporary of Cuvier
- Legacy: “The guy that was wrong”
- Published his theory of evolution in 1809, the year that Darwin was born
- Saw evolution as striving
o Life driven from simple to complex
Complex species descended from microbes
Microbes continually generated spontaneously
o Adaptation occurs through inheritance of acquired changes
Related Ideas Associated with the Lamarckian model of evolution
1. “Use and Disuse” idea
o Body parts that are used extensively become larger and stronger (and converse)
and this influences the hereditary material.
2. Inheritance of acquired characteristics idea
o These characteristics acquired by use and disuse are inherited in such a way that
the offspring have phenotype that have an accentuated trait if…
…the parent used the character…
…or that have decreased development of the trait if the parent did not Misconception based on Lamarckian Ideas: Organisms evolve adaptations they “need”
1. Evolution cannot identify needs
o Mutations do not occur because they would be adaptive in an environment
o If beneficial mutations happen to occur they may increase through natural
(See Page 56)
2. Evolution results from individuals adapting to environment
o Evolution only works on inherited traits
Acquired changes are not passed to offspring
o Populations evolve; individuals do not
Evolution results from changes in allele frequencies
(See Page 55)
November 24, 1859
- Publication of Charles Darwin’s On The Origin of Species
- “Pivotal” point in Biology and Human Affairs
Two Major predictions of Evolution
A. Species are not static but change through time
B. Species show varying degrees of relatedness and so are not independent.
A. Evidence for Change through Time
o 1. Vastness of Time
o 2. Extinction
o 3. Transitional Features
o 4. Vestigial Features
o 5. Real – time examples of changes
1. Aging Rocks and Fossils
Most fossils are in sedimentary rocks, formed by sediments laid down in
We know relative ages by their vertical order (Younger strata are on top)
Strata at different horizontal locations can be correlate