tuesday march 19, 2013 warm-up: how does a fossil record show that species have changed over time ?...
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Tuesday March 19, 2013 Warm-up: How does a fossil record show that species have changed over time ? AS: BrainPop. - PowerPoint PPT PresentationTRANSCRIPT
Tuesday March 19, 2013
Warm-up:How does a fossil record show that species have changed over time?
AS: BrainPop
MYP Unit question: How do you respond to changes in your environment?
Area of Interaction:Environment: Develop students' awareness of their interdependence with the environment so that they understand and accept their responsibilities.
Learning Target:Today I am learning about Charles Darwin because I need to know the discoveries he made about evolution.
Evolution Descent with
Modification: A Darwinian View of Life
Evolution Defined Evolution:
gradual hereditary changes in groups of living organisms over time.
November 24, 1859
Lamarck’s Theory• Jean Baptiste de
Lamarck, 1809• First theory of
evolution- how species change
Lamarck’s Theory
• **Inheritance of acquired characteristics- The changes acquired during an animals lifetime from use and disuse may be passed on to its offspring.
• Law of use and disuse- parts used by animal become stronger, parts used less become weaker
Darwin vs. Lamarck
Charles Darwin• Father of Evolution• Developed the theory of
evolution after his trip on the H.M.S Beagle
• Published the Origin of Species on November 24,1859
Darwin’s Finches
The finches beaks were different based on the type of food they ate.
Actual photos of the finches
Niches of Darwin’s Finches
Keep in mind……
• Populations or species evolve, not individuals
Major pieces of Evidence for Evolution1. Fossils2. Comparative Anatomy (homologous structures)3. Selective Breeding of Animals and Plants
1. Fossil EvidenceFossils: remains and traces left behind by organisms
-most direct evidence for evolution-provides a record of ancient organisms that have existed-able to generate a timeline-ancestral descent and lineages can be generated
Types of Fossils: imprints, hair, nails, tissue, and other remains
Locations: sedimentary rock, ice, amber, tar, quicksand,
petrification
Evidence: 1. The Fossil Record
• Shows succession of forms over time
• Transitional links• Vertebrate descent
Evolution Evidence: 2. Comparative AnatomyTypes of Structures:• A. Homologous
structures (same structure, diff. use)
• Shows possible descent from a common ancestor
Homologous Structures
6. Selective Breeding• We have bred various animals and plants
for specific purposes, selecting the traits WE want them to acquire.
• The process in which humans select which plants or animals to reproduce based on certain desired traits is called selective breeding.
• Ex- horses, dogs, strawberries, corn• This is controlled evolution.
Darwin’s Theory1. Variation- There is a natural variation in any
population. Every individual has its own combination of traits.
2. Overproduction- more offspring are born than survive.
3. Struggle to Survive- members of a species compete for food, habitat, etc. (limits population)4. Reproduction- individuals that are best adapted to their environment are likely to have many offspring that survive.
Natural selection- “survival of the fittest”- The species most fit for their environment will survive to pass on their traits.
Darwin’s Theory of Natural Selection
What Is Natural Selection? Darwin proposed the theory that evolution happens through a process that he called natural selection. Individuals that are better adapted to their environment survive and reproduce more successfully than less well adapted individuals.
7. Examples of Natural Selection
• Peppered moth
• antibiotic resistance
Examples of Modern (Recent) Evolution
• Peppered Moth- during day sits on tree trunk. More active at night.
• Before 1850 tree trunks were light in color, and most moths were gray.
• After 1850 (industrial revolution), the predominant color of moth was black, which matched the soot on the trees.
peppered moth activity
Key Points to Remember• A population evolves not an individual
organism• The accumulation of small changes over long
periods of time results in larger changes• A new species emerges with slightly different
characteristics usually because of being isolated.
• How and why organisms are able to transmit heritable traits to the next generation was not explained by Darwin.
• Common Ancestry!
Final words…...
• “Absence of evidence is not evidence of absence.”