Darwin’s Discovery and Chimps and Humans Human Evolution Darwin’s Discovery and Chimps and Humans

Standards: BI.7 a. Students know why natural selection acts on the phenotype rather than the genotype of an organism. BI. 8. a. Students know how natural selection determines the differential survival of groups of organisms. BI. 8. b. Students know a great diversity of species increase the chance that at least some organisms will survive major changes in the environment BI. 8. e Students know how to analyze fossil evidence with regard to biological diversity, episodic speciation, and mass extinction.

Standards Explanations: BI7. a: Means: NS acts on the physical or physiological traits of an individual. BI7. d. The more genetic variation a species has the better chance they will have of surviving a changing environment because atleast some individuals will have the characteristics needed to survive. BI. 8. a. Survival of the fittest and the struggle for existence. B I. 8.b. The more variety of organisms there are in an environment the better the chances are that some organisms will survive any major environmental changes. BI8. e. Trends in fossil evidence show evolutionary patterns

Objectives: SWBAT (in regards to human evolution) Explain how natural selection determines the differential survival of groups of organisms. Analyze multiple sources of evidence for evolution. Explain how a great diversity of species increase the chance that at least some organisms will survive major changes in the environment Analyze fossil evidence with regard to biological diversity, episodic speciation, and mass extinction.

What we know about Evolution so far… Evolution-change in a species over time Natural variations appear in populations because of genetic variations. These natural variations can lead to beneficial adaptations. Beneficial adaptations will appear in future generations because of the principles of natural selection. These “ natural selections” drive evolution by changing the inherited characteristics of the population. There are multiple sources of evidence supporting evolution as a theory.

(Review) Where does the genetic variation come from for evolution? Gene pool-combined alleles for all the individuals in a population Genetic variation is stored in the gene pool Alleles-different forms of trait (eye color) Allele frequency-measure of how common an allele is in a population

(Review)What evidence is there for evolution? Fossils Geologic Age of the Earth Anatomy and Physiology Molecular (DNA, “primordial soup”)

Darwin “Light will be thrown on the origin of man and his history” Didn’t talk about humans in On the Origin of Species, to avoid prejudice of his findings 1871, The Descent of Man and Selection in Relation to Sex

Accepted Theories Theory-scientific principle, supported by a large body of evidence Gravity Cell Theory Mendelian Genetics

Human Evolution

What is Human Evolution? Humans and great apes shared a common ancestor 5 million years ago Common ancestor was a knuckle-walker

What is Human Evolution? Modern humans have an ancestor that evolved into the humans we are today Chimpanzees are closely related to humans because they share this ancestor

Morphological Evidence of Shared Ancestry Morphology-structure and form of plants and animals Big brain, relative to body size More upright posture Arm structure (side to side) Teeth Binocular vision Opposable thumb Five fingers and toes

Molecular Evidence of Shared Ancestry between Chimps and Humans DNA sequences 96-99% identical DNA sequences code for similar proteins Both have lots of deletions in their DNA sequences Allows opportunities for mutations (evolution)

Shared Behaviors Tool usage Child rearing Social interactions Emotions Delayed sexual maturity Hunting

BIG BIG IDEA!!! If chimps and humans share a common ancestor then this would suggest that humans’ ancestor changed over time=evolution!!!!

Summary Questions True/False-Humans evolved from monkeys. How similar are humans and chimps genetically? List 3 morphological similarities between humans and chimpanzees. What is the evolutionary relationship between humans and other primates?