EVOLUTION Neanderthal Modern day human Homo neanderthalensis Homo

EVOLUTION Neanderthal Modern day human Homo neanderthalensis Homo sapiens

If evolution was condensed into 1 day…. . yrs.

Evolution- change in organisms over time “the diversity of living things as well as their unity may be the result of evolution” The theory of evolution suggests that organisms that exist today evolved from earlier, more primitive forms over a long period of time. Evidence of Evolution 1. Fossils- shows common ancestry among organisms ~any remains or trace of a once- living organism sedimentary ~found in _________rock*, ice, tar or amber *sedimentary rock is a type of rock formed from layers of particles that settled to the bottom of a body of water, often containing fossils

~the ages of rocks have been determined by __________ radioactive dating older, simpler ~lower layers of rock contain ________life forms newer, more complex ~upper layers of rock contain ___________life forms

2. Comparative Anatomy- shows common ancestry among organisms a. homologous structures- structures in various organisms that are similar in structure and origin but have different functions in each organisms ex). whale flipper, bat wing and human arm

b. vestigial structures- structures that were once functional but no longer are. ex). appendix, tailbone, wisdom teeth Discover 6/04

3. Comparative Embryology- shows common ancestry among organisms w/a backbone When you compare vertebrate______ embryos, at some point in development, they all have similar appearances (gill slits, tails) Fish Salamander Tortoise Chick Hog Cat Rabbit Human

4. Comparative Cytology- shows common ancestry among organisms the study of cells ~Cytology = ___________ ~all living things are made of cells ~all cells have similar organelles with similar functions 5. Comparative Biochemistry- shows common ancestry among organisms ~all living things contain similar compounds enzymes hormones DNA glucose _________________ ~the closer the relationship between organisms, the greater the similarity of their chemicals (humans can use insulin from sheep and pigs!)

Theory of Spontaneous Generation Idea that living things could arise spontaneously from things like mud, sweat, decaying meat. Redi disproved this theory. A relatively simple sketch of Redi's experiment regarding spontaneous generation. Starting from the left, the first flask is capped, and no maggots grow within it, then in the second flask flies are kept out, but the mesh allows maggots to grow within, and finally flies are allowed into the third flask where maggots grow.

THEORIES OF EVOLUTION 1. Jean Baptiste Lamarcka. Theory of use and disuse- “use it or lose it”. He theorized that if you need a structure and use it , it will become more developed over time. Likewise, if you no longer need a structure (appendix, tail) and stop using it, it will decrease in size, become non-functional or disappear. b. Theory of Acquired Characteristics. He believed that traits acquired in a lifetime are passed on to offspring (like my acquired taste for chocolate!)

2. August Weismanndisproved Lamarck's theory of acquired characteristics. His experiment: he removed the tails of mice, mated them and all of the offspring HAD tails! Other examples that support Weismann: dog breeds with clipped tails and ears, circumcision

3. Charles Darwin- theorized that evolution occurred as a result of Natural Selection. . The main points of his theory: a. overproduction- most species produce more offspring than can survive because of limited food and space b. competition- overproduction leads to a struggle for available food, water, space and mates c. survival of the fittest~variations among individuals make some better adapted or more “fit ” ~the “fit” survive because they are best adapted to the environment ~(the “fit” are not necessarily the strongest) Look at these examples of “fit” organisms: leaf fish, frog, spider, ptarmagin

d. natural selection- nature “selects” organisms with optimal traits (the “fittest”) to survive and be the parents of the next generation. This next generation will inherit the favorable characteristics that enabled their parents to survive & reproduce e. speciation- when a new species arises with helpful variations/adaptations that have accumulated over many generations An older Darwin

Survival of the fittest……this tree has adapted to grow on the side of a hill (Thatcher Park, 9/05)

MODERN THEORY OF EVOLUTION a. Today’s theorists accept Darwin’s ideas of natural selection, BUT Darwin’s theory DID NOT address how variations arise in a population. For example, why do some giraffes have long necks and some have short ones? The answer is from gene mutation and random fertilization recombination of genes during _________ The same thing goes for humans. We’re all different because of mutations and combination of genes from our different parents.

b. natural selection: nature has selected the fittest organisms in the following instances: ~insects that are resistant to pesticides (are fit enough to survive and reproduce) ~bacteria that are resistant to antibiotics (are fit enough to survive and reproduce). You’ve all probably been on antibiotics and have noticed that you’ve taken different brands. That’s because the bacteria build up a resistance to the old antibiotics. c. Geographic Isolation~small population becomes isolated (mountain range, body of water, Pangea) ~they adapt to their new environment and become so different they can no longer interbreed with the original population ~this inability to breed with the original population is called ________________ ~overreproductive time , this leads to isolation speciation: _______________ development of a new Islands species ex). Darwin’sthe finches on the Galapagos that

d. Rate of Change- there are 2 different theories on how long it takes for evolution to occur: 1. Gradualism- evolution occurs gradually, slowly and continuously 2. Punctuated Equilibrium- when species have long periods of stability and then have sudden, brief intervals of major change. Gradualism Punctuated. Equilibrium

II. The Heterotroph Hypothesis. . . how did life begin on earth? ? ? primitive conditions inorganic materials “hot, thin soup”: gases: -NH 3 (ammonia) -CH 4 (methane) -H 2 (hydrogen) sun and lightning provided the ENERGY needed to SYNTHESIZE materials small organic molecules formed (sugars, amino acids) Stanley Miller reproduced this theory in his lab sun, lightning and energy= SYNTHESIS

Video clip, S. Miller’s expt 15 mins ****

large organic molecules were formed (proteins, carbs) Sidney Fox reproduced this theory in his lab large molecules clumped together aggregates (colonies) were now present These were heterotrophic (no CO 2 available) they reproduced! these aggregates are now considered ALIVE BECAUSE THEY CAN REPRODUCE no free oxygen these heterotrophs were anaerobic heterotrophs produced CO 2 during respiration/fermentation photosynthesis now possible

autotrophs evolved produced oxygen aerobes evolved

Quick Summary Heterotrophs anaer. resp CO 2 given off photo. O 2 synthesis autotrophs producedaerobes

(fossils, comparisons) you cannot inherit acquired characteristics (simpler) (mutation & crossing-over) survival of the fittest

Pine bush, rainforest An increase in biodiversity increases the stability of an environment

evolution fossils comparative biochem homologous vestigial Darwin Lamarck speciation gradualism punctuated equil. reproductive geographic spontaneous generation Origin of life aggregate O 2 photosyn They were anaerobic respiration or ferm sun, lightning, radiation

Notes: The Unity and Diversity of Living Things All living things have the potential to carry out life functions. This is one fact that unites living things. But, living things are not the same. There are billions of different living things. How do we tell them apart? How do we keep them organized?

Biological Diversity (don’t put in notes) Edward Wilson, 1999 The total # of kinds of plants, animals and microorganisms known to science (those which have a scientific name) is about 1. 4 million. But, the actual # is estimated to be between 10 and 80 million. “We don’t know even to the nearest, the amount of diversity in the world. ” Out of the 1. 4 million named organisms, there approximately 750, 000 insects 242, 428 plants 123, 151 arthropods 46, 983 fungi 19, 056 fish 9, 048 birds 4, 000 mammals

Humanity is creating a radical new environment too quickly to allow species to adjust. Species need thousands of years (maybe millions) to assemble complex genetic adaptations. Most of life is consequently at risk (of extinction)” ……this is why human impact is directly related to the environment. Now, back to notes….

The Diversity of Life In order to study the billions of living organisms, scientists need to have an organized system: a classification system. Taxonomy is the branch of Biology that studies classification. Hundreds of years ago, scientists classified living organisms into 2 groups called kingdoms. Plant Animal But, they kept discovering organisms (ex. mushrooms) that didn’t fit into either kingdom. Today, we use a 5 kingdom classification system: 1. Monera 2. Protista 3. Fungi 4. Plant 5. Animal

But, even these groups are too broad to have an organized system so the kingdoms are broken down into smaller & smaller groups: Kingdom Broadest, largest group Phylum Class Order Family Genus Species Smallest, most specific (hint: species~specific) How do we place organisms in the proper K, P, C, O, F, G, S? We examine them and group them according to the following:

1. evolutionary relationships (did they come from the same ancestor? ) 2. the presence (eukaryotic) or absence (prokaryotic) of a nuclear membrane within the cell. 3. unicellular or multicellular? 4. type of nutrition (heterotrophic or autotrophic)

Kingdom Monera Protista a. protozoa b. algae Characteristics • most primitive kingdom • lacks a nuclear membrane (prokaryotic) • some organelles Examples • bacteria • blue green algae • mostly unicellular • eukaryotic heterotrophic autotrophic paramecium ameba spirogyra

Kingdom Fungi Characteristics • Eukaryotic • Multicellular • Have branched filaments called rhizoids (like roots) that secrete digestive enzymes into the surface that the fungi is on. The fungi then absorb the digested material • heterotrophic Examples mushroom yeast bread mold athlete’s foot fungus see next slide Plants a. Bryophytes • multicellular • photosynthetic • autotrophic lack vascular tissue (xylem, phloem) have no true roots, stems, leaves b. Tracheophytes do have vascular tissue and true roots, stems, leaves moss fern water lily sycamore tree

pores • hollow body cavity • 2 cell layers flatworms • round worms • parasitic sponges hydra jellyfish planaria tapeworm liver fluke trichina hookworm heartworm segmented worms earthworm leech

soft-bodied 2 shells clams, oysters 1 shell: snail no shell: slug, octopus, squid lobster, crab, shrimp exoskeleton (chitin) centipedes: 60 legs millipedes : 600 legs jointed spiders, scorpions appendages bees, beetles, cockroaches starfish sea cucumber spiny skinned endoskeleton dorsal nerve cord brittle star sea urchin many including: reptiles birds mammals

prokaryote eukaryote……………………. . hetero but chemosyn in archaebact no uni hetero no uni bacteria, ameba, blue-green paramecium algae auto yes uni/ colony spirogyra hetero auto hetero no yes no multi mushroom fern human bread mold tree dog

Scientific Naming There is a naming system called binomial nomenclature two name naming system Just like we all have a first and a last name, so do organisms. Scientists refer to organisms by their genus (1 st name) and species (2 nd name) Ex). Felis domesticus = common house cat genus species

Rules for using scientific names: 1. Genus is always capitalized 2. Species is always lower case 3. Both words are either underlined or italicized Note: a species is defined as a group of organisms that can mate and produce fertile offspring G s

3 11 8 9 7 2 10 4 6 1 5

coccus Diplococcus pneumonia Bacillus botulinum Bacillus tetani Bacillus anthracis strep Bacillus diplo Organizes by structure, shape, arrangement

Dipteron cyclops Helikopteron bacillus Dipteron polyoculus Sessilis terretris Podus cyclops Sessilis aquatilis Podus biantennae Podus anoculus Podus monoantennae Podus triantennae Helikopteron coccus