Introduction to Evolution

Characteristics of an Organism

• Membrane bound cells

• Processes hereditary info

• Evolving

Theory

Explanation for phenomenal/general collection of observations supported by lots of evidence

Main Theories

1. Cell Theory

2. Chromosome Theory of Inheritance

3. Theory of Evolution by Natural Selection

Cell

Highly organized compartment, bounded by plasma membrane and has concentrated chemicals in aqueous solution

Hypothesis

Testable statement that explains something observed

Experiment

Allows to test effects of a factor on a particular phenomenon

Prediction

Measurable result that has to be right if hypothesis is correct

Difference between hypothesis and predictions

• Hypothesis explains impacts/affects, but no direction (x affects y)

• Predictions tells you specifically whether y will decrease or increase, has direction

Spontaneous Generation

Organism arise spontaneously under certain conditions from nonliving materials

Cell Theory

All organisms are made of cells that came from preexisting cells

Chromosome Theory of Inheritance

Genes are units of heredity and are found in chromosomes

Genes

Genetic info located on chromosomes that codes for cell products

Central dogma

Genetic information flows from DNA > RNA > Protein

Special Creation

All species were made separately, unrelated and unchanging

Darwin’s Theory

All species have common ancestry and have characteristics that change generation to generation

Microevolution

Change over time

Macroevolution

Species splitting and diverging

Population

Group of individuals of same species in same area and time

Evolution

Change in allele frequencies over time through adaptive or nonadaptive methods

Conditons for Natural Selection

• Vary in traits are heritable

• Certain versions of the traits help them reproduce more than other versions in certain environment

Speciations

Populations diverge to make new species

Fitness

Ability of individuals to make a viable, fertile offspring

Adaptions

Heritable trait that increases fitness in a specific environment

Factors of a Good Experiment

• Has control groups for manipulating experiments

• Eliminate confounding variables

• Has multiple trials

• Randomization

Pattern

Observation about natural world

Process

Mechanism that produces that pattern

Typological Thinking

Every organism is perfect type created by god

Scale of Nature + Typological Thinking

Organisms are ordered into a linear way based on size and complexity

Inheritance of Acquired Characters

Organisms evolve up the chain through phenotypic changes from environment over time

Phenotype Plasticity

Individual phenotype changes from environment

Myths about Natural Selection

• Only sorts existing variants and change population proportions

• Not goal directed, random

• Doesn’t get better/complex

Genetic Correlation

Selection favouring alleles for 1 trait causes a correlated suboptimal change in allele for another trait

Pleiotropy

Single allele affects multiple traits

Fitness Trade Off

Compromise between fitness traits, every adaptation is a compromise

Fossils

Any traces of organisms that lived in the past

Geological Time Scale

Eons > eras > periods > epochs

Radiometric Dating

Comparing radio of parent and daughter atoms from a newly formed rock to the rock sample

Law of Succession

Extinct species are similar to living species in same geographical area

Transtional Features

Traits in fossil that are in between ancestral and derived species

Homology

Similarity in traits from a common ancestor, NOT because they evolved from a species

Genetic Homology

Similarity in genetic sequences

Developmental Homology

Similarity in embryos

Structual Homology

Similarity in adult morphology

Internal Consistency

Multiple kinds of data have the same conclusion

Evolution by Natural Selection occurs when

Heritable variation leads to differential reproductive success

Acclimation

Developing a trait/becoming accustomed based on environment individually