Ch 14/15 Lecture Evolution the Theory

First Spontaneous generation ____ experiment

____________ Experiment

History ________ experiment

First Organisms ____________ Cyanobacteria Made Oxygen

_____________ Theory

A sea voyage helped Darwin frame his theory of evolution Aristotle and the Judeo-Christian culture ________ that species are fixed Fossils suggested that life forms change This idea was embraced by ________ in the early 1800s

While on the voyage of the HMS Beagle in the 1830s, Charles Darwin observed similarities between ______ and fossil organisms the diversity of life on the Galápagos Islands, such as blue-footed boobies and giant ________

The voyage of the ________ Great Britain Europe North America Pacific Ocean Atlantic Ocean Africa Galápagos Islands Equator South America Australia Andes Cape of Good Hope Tasmania Cape Horn New Zealand Tierra del Fuego

Darwin became convinced that the Earth was old and continually _______ He concluded that living things also change, or evolve over generations: _______ advantage He also stated that living species descended from earlier life-forms: descent with __________

Natural Selection ________ of the ________ Organisms which reproduce add to gene pool & __________

Darwin proposed natural selection as the mechanism of evolution DARWIN’S THEORY AND THE MODERN SYNTHESIS Darwin proposed natural selection as the mechanism of evolution Darwin observed that organisms produce more ________ than the environment can support organisms vary in many __________ these variations can be _________

Darwin saw natural selection as the basic mechanism of evolution Darwin concluded that individuals best suited for a particular environment are more likely to survive and reproduce than those less well ________ Darwin saw natural selection as the basic mechanism of evolution As a result, the proportion of individuals with __________ characteristics increases Populations gradually change in response to the ___________

Darwin also saw that when humans choose organisms with specific characteristics as breeding stock, they are performing the role of the environment This is called ________ selection Example of artificial selection in plants: five vegetables derived from wild _________ Figure 13.4A

Example of artificial selection in animals: dog __________ English springer spaniel German shepherd Yorkshire terrier Mini-dachshund Golden retriever Hundreds to thousands of years of breeding (artificial selection) Ancestral dog

Thousands to millions of years of natural selection These five canine species evolved from a common ancestor through natural selection ___________ radiation African wild dog Coyote Fox Wolf Jackal Thousands to millions of years of natural selection Ancestral canine

Connection: Scientists can observe natural selection in action Evolutionary adaptations have been observed in populations of birds, insects, and many other organisms Example: camouflage adaptations of mantids that live in different environments

Insecticide application The evolution of insecticide resistance is an example of natural selection in action Chromosome with gene conferring resistance to insecticide Insecticide application Additional applications of the same insecticide will be less effective, and the frequency of resistant insects in the population will grow Survivor

Connection: The evolution of antibiotic ___________ in bacteria is a serious public health concern The excessive use of _________ is leading to the evolution of antibiotic-resistant bacteria Example: Mycobacterium tuberculosis

A species is a group of populations whose individuals can ________ and produce ______ offspring Human populations tend to concentrate locally, as this satellite photograph of North America shows The modern synthesis connects Darwin’s theory of natural selection with population genetics Figure 13.6

The gene pool of a nonevolving population remains constant over the generations Hardy-Weinberg _________ states that the shuffling of genes during sexual reproduction does not alter the proportions of different alleles in a gene pool To test this, let’s look at an imaginary, ________ population of blue-footed boobies Webbing No webbing

We can follow alleles in a population to observe if Hardy-Weinberg equilibrium exists Phenotypes Genotypes WW Ww ww Number of animals (total = 500) 320 160 20 Genotype frequencies 320/500 = 0.64 160/500 = 0.32 20/500 = 0.04 Number of alleles in gene pool (total = 1,000) 640 W 160 W + 160 w 40 w Allele frequencies 800/1,000 = 0.8 W 200/1,000 = 0.2 w

Recombination of alleles from parent generation W sperm p = 0.8 W egg p = 0.8 SPERM EGGS WW p2 = 0.64 w sperm q = 0.2 w egg q = 0.2 WW qp = 0.16 Ww pq = 0.16 ww q2 = 0.04 Next generation: Genotype frequencies 0.64 WW 0.32 Ww 0.04 ww Allele frequencies 0.8 W 0.2 w

______ conditions are required for Hardy-Weinberg equilibrium The population is very _____ The population is _______ ________ do not alter the gene pool Mating is _________ All individuals are _______ in reproductive success

Divergent Evolution: _________ structures

Vestigial structure: _________ Evolution

__________ Evolution Analogous Structures similar structures with different origins Used to fly but not made of the same stuff.

Evolution Underground Evolution has generally been thought of as a very _______process However, examples of rapid evolution have been observed

One example of rapid evolution occurred among mosquitoes who ______ into the London underground In less than 150 years, Culex pipiens evolved into a new mosquito species, Culex molestus The origin of new species is called ________

The isolated mosquitoes adapted to their new underground environment They altered their __________________ ________________________________ ___________ barriers that isolate populations are just one of many mechanisms in the evolution of species

Geographic isolation can lead to speciation MECHANISMS OF SPECIATION When a population is cut off from its parent stock, species evolution may occur An ______ population may become _________ unique as its gene pool is changed by natural selection, genetic drift, or mutation This is called _________ speciation

Islands are living laboratories of speciation On the Galápagos Islands, repeated isolation and adaptation have resulted in _________ radiation of ____ species of Darwin’s finches

__________ radiation on an island chain 1 Species A from mainland 2 B A B 3 B B 4 C C C C D C D 5

Niche Every organism has a specific “______” and “____” No two species can hold the same niche in the same place for a long period of time

______ drift Random Change in Gene pool frequency 1 or 2 humps or tusks

There are several potential causes of microevolution Genetic drift is a change in a gene pool due to chance Genetic drift can cause the _____________ Hunting to extinction can cause bottleneck Bottlenecking event Original population Surviving population

Reproductive barriers keep species separate _________ and _________ reproductive barriers prevent individuals of different species from interbreeding

_____________ in blue-footed boobies is an example of one kind of prezygotic barrier, behavioral isolation Many plant species have flower structures that are adapted to specific pollinators This is an example of _________isolation, another prezygotic barrier

Hybrid sterility is one type of postzygotic barrier A horse and a donkey may produce a hybrid offspring, a mule Mules are _______

Sexual selection may produce sexual ___________ Sexual selection leads to the evolution of secondary sexual characteristics These may give individuals an advantage in mating

How fast is Evolution?

Slow!!! __________ over billions of years slow changes How fast is evolution? Slow!!! __________ over billions of years slow changes

Fast!!! How fast is evolution? ____________ equilibrium short periods of quick change

Fast!!! _____________ death of many species opened space for new ones How fast is evolution? Fast!!! _____________ death of many species opened space for new ones