Evolution Objective: K1 - Analyze & evaluate how natural selection produces changes in a population, not individuals & describe the three types of isolation that cause speciation

I. Population Genetics - study of the traits in a population A. Population – a group of interbreeding organisms (a species) living in a given area B. Gene Pool – combined genetic material of all the members of a population

C. Allele – forms that a gene can take D. Allele Frequency – the number of each allele for a trait as a fraction of all the alleles for a particular trait a. Example: 8 alleles total, 4 are green. Allele frequency of green = 4/8 or 1/2

II. How do you get NO EVOLUTION - NO evolution = genetic equilibrium - Five conditions must be met to have genetic equilibrium. 1. Random mating 2. Large Populations 3. No Immigration or Emigration 4. No Mutation 5. No Natural Selection - Genetic Equilibrium does not occur - It is only theoretical

III. Generalization 1. If gene pools do not remain the same over time, they must change. 2. This “changing of the gene pool” (allele frequency) has a name —› Evolution. 3. Evolution – the changes in the gene pool of a population over time.

IV. Speciation – formation of a new species 1. Behavioral Isolation - occurs when 2 populations are capable of interbreeding but have differences in courting rituals or other reproductive strategies

2. Geographic Isolation - 2 populations are separated by geographic barriers ●examples: rivers, mountains, bodies of water

3. Temporal Isolation - 2 or more species reproduce at different times

What a Beak! Lab

Objective: K2 - Analyze & evaluate the relationship of natural selection to adaptation and to the development of diversity in & among species & how the elements of natural selection result in differential reproductive success

V. Natural Selection: a. Artificial Selection – humans select for variations in plants and animals that they find useful. b. Natural Selection – also means “Survival of the Fittest”. - Fitness in this sense does not mean strongest. - Fitness in Darwin terms means reproduction. The one who survives long enough to reproduce the most is the one with the highest fitness.

VI. Types of Selection -Evolution acts on the phenotype of the individual, not the genotype. - There are 3 types of selection that can occur on a population. i. Directional Selection – when individuals at one end of the curve have a higher fitness than individuals in the middle or at the other end of the curve.

 ii. Stabilizing Selection  – when individuals near the center of the curve have higher fitness than individuals at either end of the curve, narrowing of the graph.

 iii. Disruptive Selection  – when individuals at either end have a higher fitness and individual near the middle of the curve are selected against. - Over time with enough selection a population can go through genetic drift. a. genetic drift – random change in allele frequency.

VII. Adaptation- an inherited trait that increases a population’s chance of survival and reproduction in a particular environment A. Through adaptations, populations often become suited to a specific job called a niche. 1. niche – a habitat and the role a population plays in that habitat - job, profession, role 2. Competition arises when 2 populations occupy the same niche.

B. Mimicry - Definition: The advantageous resemblance of one species to another Purpose:  Deceives predators  Provides a form of camouflage for protection  Example: The viceroy butterfly is a mimic of the monarch butterfly because the monarch is toxic and the viceroy is non-toxic.

M & M Allele Activity