Agenda 9/25 Ground Squirrel Case Study Bacteria Evolving Video Introduction to Microevolution Homework: 1. Natural Selection Video and Notes 2. Chp 23 Reading and notes (due Thursday) FRQ workshop Thursday morning!- how you get points for test corrections (if your grade was below an 80)

Ecology Unit Exam Tips and Tricks Do NOT waste all your FRQ or MC time on the math, each math question is only 1 point Be very very specific in your FRQ details. A lot of you missed easy points because you didn’t ‘state the obvious’ Answer the easy question firsts Honestly, study more!

Alarm Squirrels https://youtu.be/RmfDbWH46bQ Why do they call? Complete the case study with your group, but write answers individually. Case study posted on website, use your chromebooks to access it

Does altruism really exist?

Why is evolution important? https://youtu.be/plVk4NVIUh8

Charles Darwin Charles Darwin is credited with proposing the mechanism of natural selection He traveled around the world and recorded his observations 1. Populations change 2. More offspring are produce than can survive 3. There is variation in populations that is inherited 4. That variation will affect an organisms ability to survive and reproduce

Charles Darwin By the 1870s the scientific community and much of the general public had accepted evolution as a fact. However, many favored competing explanations and it was not until the emergence of the modern evolutionary synthesis from the 1930s to the 1950s that a broad consensus developed in which natural selection was the basic mechanism of evolution. In modified form, Darwin's scientific discovery is the unifying theory of the life sciences, explaining the diversity of life. http://en.wikipedia.org/wiki/Charles_Darwin

Adaptations Adaptation- a genetically controlled trait that gives an organism a reproductive advantage, ensuring that trait is passed on to future offspring This trait may also allow the individual to survive longer meaning more reproduction Compare and contrast these hares and identify the differences in their traits

Biological Fitness The ability to survive and reproduce Refers to the contribution of genes to the gene pool and NOT have long an organism lives What makes the hares fit for their environment?

Environmental Change Environments are not static, but always changing Traits and adaptations that were once favorable, may later become unfavorable Peppered moths: Prior to industrial revolution only 2% of the moths were dark, 50 years later 95% of the moths were dark Propose an explanation!

Evolution Change in the inherited characteristics of biological populations over successive generations More simply: genetic change over time Diversity in DNA  Diversity in organisms

Microevolution The change in gene frequency within a population Why would this occur?

Microevolution The change in gene frequency within a population Why would this occur? natural selection favored the gene the population received new immigrants carrying the gene (gene flow) nonresistant genes mutated into a resistant version of the gene random genetic drift from one generation to the next

Microevolution A gene is a sequence of DNA nucleotides that specify a particular polypeptide chain. Genes code for proteins. An allele is a particular form of a gene. For example: B represents the allele for black coat color and b for white coat color. Selection acts on phenotype because differential reproduction and survivorship depend on phenotype not genotype. Natural selection acts on individuals, but only populations evolve. Really emphasize those last two bullets! When students write about evolution it is VERY important that they can “say what they mean and mean what they say”. These last two bullets belong in the response to any evolution free-response question!

More Evolution Terms Species-a group of interbreeding organisms that produce viable and fertile offspring in nature Gene pool-sum total of all the genes in a given species Allelic frequency-is the percent occurrence for a given allele