Transcript 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?