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 (1707-1778) • 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:

1.1. Kingdom (Keep)Kingdom (Keep)

2.2. Phylum (Pots)Phylum (Pots)

3.3. Subphylum(Sparkling) Subphylum(Sparkling)

4.4. Class (Clean)Class (Clean)

5.5. Order (or)Order (or)

6.6. Family (Food)Family (Food)

7.7. Genus (gets)Genus (gets)

8.8. Species (Stuck!)Species (Stuck!)

Who Was Charles DarwinLabel your paper :

1.

2.

3.

4.

5.

Write 5 facts from the short video clip on Darwin…

http://www.pbs.org/wgbh/evolution/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.

Left page 126: Figure 16-13 page 406Figure 16-13 page 406

Today’s Activity: Darwin’s Great Voyage!!! IN 128 & 129

1. Plot Darwin’s 17 Stops on map IN: 166

2. Mark the date next to each stop

3. List one observation he made at each stop on the map

http://www.pbs.org/wgbh/evolution/educators/lessons/lesson2/act1.html

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 FittestSurvival of the Fittest” • Organisms that adapt

to their environment survive while those that do not adapt disappear

• N.S. leads to adaptationsadaptations 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

http://www.pbs.org/wgbh/evolution/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 DevelopmentVestigial Structures • Reduced or nonfunctional vestigial structures

– hind limbs in whales• provide evidence of an organism’s

evolutionary history.

http://www.pbs.org/wgbh/evolution/library/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 WorkExamples 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.

1) SpeciationSpeciation • Speciation begins as a population adapts to its

environment. 2) Forming Subspecies • Populations of the same species that differ

genetically b/c of adaptations to different living conditions are called: subspeciessubspecies.

• 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

• ClassificationClassification 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.