Evolution (Part 1) IN: 163 & 165

Incorrect Theories of Evolution: Lamarck Lamarck proposed an incorrect mechanism for how organisms evolve –Simple life forms continually came into existence from dead matter –Continually become more complex –More "perfect" -- as they transformed into new species. He correctly pointed out that change in species is linked to an organism’s environment.

Linnaeus ( ) Swedish Botanist Tried to Classify all of life on earth Kingdoms, Classes, Orders, Genera, & Species He influenced Darwin’s Theories Today we classify life by this order: 1.Kingdom (Keep) 2.Phylum (Pots) 3.Subphylum(Sparkling) 4.Class (Clean) 5.Order (or) 6.Family (Food) 7.Genus (gets) 8.Species (Stuck!)

Who Was Charles Darwin Label your paper : Write 5 facts from the short video clip on Darwin… n/library/11/2/e_s_2.html

Darwin’s Observations Animals on the coast of S. America: – Resembled those on the nearby islands –Evolved differences Or –Descended w/ modification after separating from a common ancestor.

Figure page 406 Left page 126: Figure page 406

Today’s Activity: Darwin’s Great Voyage!!! IN 128 & Plot Darwin’s 17 Stops on map IN: Mark the date next to each stop 3.List one observation he made at each stop on the map

Evolution (Part 2) IN 169 & 171

Growth of Populations Darwin was influenced by Thomas Malthus He wrote: Populations grow as much as the environment allows.

Evolution by Natural Selection The process of: Survival of the Fittest “Survival of the Fittest” Organisms that adapt to their environment survive while those that do not adapt disappear adaptationsN.S. leads to adaptations in a population.

Label Paper: 1.Genetic Variation a. b. 2.Overproduction of Offspring a. b. 3.Struggle for Existence a. b. 4.Differential Survival & Reproduction a. b. Natural Selection Video ution/library/11/2/e_s_4.html 6 min 39 sec

Darwin’s Ideas Updated 1) Change Within Populations N.S. causes the frequency of certain alleles in a population to change over time. 2) Species Formation Under certain conditions, change within a species due to reproductive isolation can lead to new species. 3) The Tempo of Evolution Gradualism is a process of evolution in which speciation occurs gradually Punctuated Equilibrium is a process in which speciation occurs rapidly between periods of little or no change.

Evidence of Evolution-- Formation of Fossils Evidence of orderly change can be seen when fossils are arranged according to their age.

Anatomy and Development Vestigial Structures Reduced or nonfunctional vestigial structures – hind limbs in whales provide evidence of an organism’s evolutionary history.

ibrary/03/4/l_034_05.html 5 min, 9 sec Whale Evolution Video Label Paper 1-5

Homologous Structures Structures in different organism that indicate a shared ancestry –include vertebrate forelimb.

Biological Molecules Evidence of Evolution-- Proteins MORE differences in amino acid sequences of distantly related species LESS differences between species that are more closely related. Nucleic Acids (what is a nucleic acid???) MORE differences in DNA sequences b/t distant relatives LESS differences between species that are more closely related.

Natural Selection at Work Examples of Evolution-- 1) Factors in Natural Selection Organisms w/traits helping them survive— reproduce & pass genes. 2) Evolution of Antibiotic Resistance Experiments show that evolution through N.S. has occurred within populations of antibiotic-resistant bacteria –Tuberculosis bacteria 3) Evolution in Darwin’s Finches Experiments show that evolution through N.S. has occurred in beak size in Darwin’s Finches.

Speciation 1) Speciation Speciation begins as a population adapts to its environment. 2) Forming Subspecies subspeciesPopulations of the same species that differ genetically b/c of adaptations to different living conditions are called: subspecies. Newly formed subspecies are on the road towards speciation. 3) Maintaining New Species Reproductive isolation through barriers keeps species from breeding with one another. Formation of New Species

Dichotomous Keys Tool used when new species is found Used to categorize different species based on physical characteristics Classification Classification is a way of separating a large group of closely related organisms into smaller subgroups. A Dichotomous Key is a listing of characteristics, such as structure and behavior, organized in such a way that an organism can be identified or classified.