Theory of Evolution Chapter 15 Part 1

What are the characteristics of this chameleon that help it hunt successfully?

Orgs are well suited to: –Where they live –What they do The most adapted species will survive and sexually reproduce, passing on the desirable traits to offspring D.W.

Why? Previous Theory: Divine creation –Every org. was created just as seen now

Additional Opposing Theories Lamarck 1809 a.Evolution by use or disuse of physical features b.These “acquired” traits are then passed to offspring Ex: giraffe long neck, cut pinky off

Charles Darwin Naturalist aboard ship “Beagle” Galapagos Islands –Finches: the birds resembled birds from South America Book he wrote: “On the Origin of Species by Means of Natural” Selection (1859)

D.W.

4 Principles of Evolution by Natural Selection

Variation All life forms vary genetically w/i a pop. It is this variation upon which selection works.

New variations in a pop. occur b/c of spontaneous mutations and the recombination of alleles from sexual reproduction. The environment cannot create mutations!

Inheritance Genetic traits are inherited from parents and passed on to offspring.

Selection Orgs. with traits that help them survive, get to live and pass on their genes to the next generation. Many org. have more offspring than can survive.

Time E. takes time, sometimes in a few generations but usually much longer.

Process of Natural Selection StepsExample 1. Variation is the raw material for natural selection Giraffes were born with alleles for varying neck lengths (short & long) 2. Living things face a constant struggle for existence Giraffes with longer necks could reach leaves in tall trees 3. Only some individuals survive and reproduce The giraffes with longer necks were better at getting food. Consequently, they produced more offspring than did giraffes with short necks. 4. Natural selection causes genetic change. Over time, long-necked giraffes became common and replaced short-necked giraffes. D.W.

4 - Evidences of E. Fossils Biochemical Similarities Anatomy & Development Embryonic Development D.W.

1. Fossil Record Absolute Dating Relative Dating Finding Transitional fossils

2. Biochemical Similarities Proteins and Amino Acid sequences –More differences will emerge as more mutations accumulate –Takes TIME for mutations to accumulate

3. Anatomy:

Homologous Structures Similar structures inherited from a common ancestor Ex: forelimbs of vertebrates Page 424

Vestigial Structures Structures that have lost most or all of their previous function Pg. 425 Wings of an ostrich

Analogous Structure Body parts in different species that are similar in function but not structure (pg 426) Example: bat wing versus butterfly wing

4. Development - Embryology Structures may develop at different rates and at different stages. Can show a common ancestor

Examples of E. Industrial Melanism: Kettlewell’s experiment (quick response) Beaks of Finches –Size and shape depended on the environment Antibiotic resistance (quick response) Other adaptations

Industrial Melanism Evolution due to industrial air pollution (light color trees turned dark) Used 2 varieties of peppered moths (light & dark), marked them, and released into industrial and non- industrial areas.

Conclusion Verified the moths who survived in each location matched the tree color. Natural Selection at work

Adaptations Are traits shaped by N.S. that increases org. reproductive success Can arise abruptly in response to strong environmental selective pressures: –Examples of environment: antibiotic resistance, pesticide resistance, pollution Natural Selection can be influenced by the environment!!!!

Examples of other Adaptations Camouflage Mimicry – resembles another species

owl lizard stingray cricket Leafy mantis

owl ptarmigan Leaf frog flounder Purple frog

Mimicry Kingsnake (non) / coral (venomous) Yellow jacket / clearwing moth