Darwin’s Discovery and Chimps and Humans

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 environmentBI. 8. e Students know how to analyze fossil evidence with regard to biological diversity, episodic speciation, and mass extinction.

Standards:

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

Standards Explanations:

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 environmentAnalyze fossil evidence with regard to biological diversity, episodic speciation, and mass extinction.

Objectives:

Evolution-change in a species over timeNatural 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.

What we know about Evolution so far…

Gene pool-combined alleles for all the individuals in a populationGenetic variation is stored in the gene poolAlleles-different forms of trait (eye color)Allele frequency-measure of how common an allele is in a population

(Review) Where does the genetic variation come from for evolution?

FossilsGeologicAge of the EarthAnatomy and PhysiologyMolecular (DNA, “primordial soup”)

(Review)What evidence is there for evolution?

“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

Darwin

Theory-scientific principle, supported by a large body of evidenceGravityCell TheoryMendelian Genetics

Accepted Theories

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

What is Human Evolution?

Morphology-structure and form of plants and animalsBig brain, relative to body sizeMore upright postureArm structure (side to side)TeethBinocular visionOpposable thumbFive fingers and toes

Morphological Evidence of Shared Ancestry

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)

Molecular Evidence of Shared Ancestry between Chimps and Humans

Tool usageChild rearingSocial interactionsEmotionsDelayed sexual maturityHunting

Shared Behaviors

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

BIG BIG IDEA!!!

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?

Summary Questions