1. Levels of Classification
Most living things have been classified based on their physical and behavioral characteristics.
There are 7 levels of classification:
Kingdom-Phylum-Class-Order-Family-Genus-Species
The kingdom level is the most broad and the species level is the most specific. There are 6 kingdoms- Archaebacteria, Eubacteria, Protists, Fungi, Plants and Animals.
Living things are typically referred to using their genus and species names. Humans are Homo sapiens. Homo is our genus name and sapien is our species name.

2. Dichotomous Key
If you don’t know the classification of a species, you can use the clues of a dichotomous key to help you.

3. Populations
A population is a group of organisms of the same species that inhabit the same area at the same time.
Most populations grow either exponentially or logistically.
Exponential growth occurs when resources are plentiful and the reproduction rate is greater than the death rate.
Logistic growth occurs if there are limited resources. Growth of the population plateaus when its carrying capacity is reached.
The number of organisms will continue to hover around the carrying capacity (will go above it and below it and above it and below it …).

5. What is the Carrying Capacity for this population of rabbits?

6. Population Genetics
The genetics of a population will remain stable unless one or more of the following events occur.
Mutation= random changes in the DNA
Natural Selection= survival of the fittest(certain genotypic groups are targeted because they are not able to survive as well as others)
Gene Flow= movement of alleles into or out of a population (immigration or emigration)
Genetic drift= changes in the alleles of a population due to random events (i.e. natural disaster or epidemic)
Non-random mating
Small population size= Allele frequencies change more drastically in small populations.

7. Each colored line represents a different genetic drift event acting on a population.
Notice that the smallest population experiences the greatest change in allele frequency over time and the largest population experiences the least change in allele frequency over time.

8. Measuring the Genetics of a Population
The Hardy-Weinberg equation calculates genetic variety in a population.
The H-W equation is:
p2 + 2pq + q2= 1 (or 100%)
q2= the frequency of homozygous recessive individuals.
2pq = the frequency of heterozygous individuals.
p2= the frequency of homozygous dominant individuals.
If the allele frequencies change from 1 generation to the next, the population has evolved.

9. Human Impact on Populations
Humans can impact populations in a variety of ways:
Selective breeding
Deforestation
Pesticide and fertilizer use
Invasive species
Antibiotics
Burning fossil fuels/global warming

10. Evidence of Common Ancestry
Charles Darwin came up with the theory that all living things can be traced back to the same original ancestor.
The evidence that supports this theory includes:
Fossils
DNA/proteins
Embryo structure
Comparative anatomy (homologous features)
Vestigial structures

11. Fossils

12. Embryos

13. Homologous Features

14. Vestigial organs

15. Cladogram
A cladogram is a diagram that shows the evolutionary relationship among different species.
As an organism evolves, there is a new branch on the cladogram.
Organisms with similar characteristics (DNA, structure, behavior) are placed more closely on the cladogram.
Characteristics that evolve between species are called derived characters.

16. Variations of Cladograms

18. 10 20 30 40 50 60 70 80 90
100
110
120
Lamprey
Frog
Bird
Dog
Macaque
Human 32 8 45 67
125

19. Create a Cladogram using the Pictures Place a “+” if the characteristic is present and a “-” if it is absent
Organism
Characteristic
Jaws
Limbs
Hair
Lungs
Opposable thumb
Upright, erect posture
Turtle
Gorilla
Human
Lamprey
Caecilian
Cat
TOTAL