How Biological Diversity Evolves Chapter 14 The origin of species What accounts for all the diversity in the millions of species (extinct and extant) on our planet? What makes these two meadowlarks different?
A variety of barriers prevent interbreeding Eastern and western meadowlarks are two different species and do not interbreed Prezygotic barriers Temporal Isolation Skunk species that mate at different times Prezygotic barriers Habitat/Ecological Isolation
Garter snake species from different habitats Prezygotic barriers Behavioral Isolation Mating ritual of blue-footed boobies Prezygotic barriers Mechanical Isolation Snail species whose genital openings cannot align Prezygotic barriers
Gametic Isolation Sea urchin species whose gametes cannot fuse Postzygotic barriers Reduced Hybrid Viability Frail hybrid salamander offspring Reduced Hybrid Fertility Postzygotic barriers
Horse Donkey Mule Mule (sterile hybrid of horse and donkey) Postzygotic barriers Hybrid Breakdown Sterile next-generation rice hybrid INDIVIDUALS OF DIFFERENT SPECIES
Prezygotic Barriers Temporal isolation Habitat isolation Behavioral isolation MATING ATTEMPT Mechanical isolation Gametic isolation FERTILIZATION (ZYGOTE FORMS) Postzygotic Barriers Reduced hybrid viability Reduced hybrid fertility Hybrid breakdown VIABLE, FERTILE OFFSPRING No Barriers
Mechanisms for speciation Allopatric speciation Sympatric speciation Allopatric speciation Ammospermophilus harrisii Ammospermophilus leucurus Sympatric speciation Chromosomes
cannot pair Species A 2n 4 Species B 2n 6 Asexual reproduction Gamete n2 Gamete n3
Sterile hybrid n5 Can reproduce asexually Viable, fertile hybrid species 2n 10 The fossil record in strata Plate tectonics and biogeography North
American Plate ATLANTIC Caribbean OCEAN Plate Juan de Fuca Plate Pacific Plate Philippine Plate
Arabian Plate Indian Plate Cocos Plate Nazca Plate PACIFIC OCEAN Key Eurasian Plate
South American Plate Australian Plate African Plate Scotia Plate Zones of violent tectonic activity Antarctic Plate Direction of movement
er Am ica Eurasia th r Africa No India South Madagascar America a
trali Antarctica Aus Mesozoic Laurasia Paleozoic Pangaea is formed. Cenozoic Present 65
135 Pangaea splits into Laurasia and Gondwana. 251 million years ago Pangea all land India collides with Eurasia. Gon
dwa na aea ng a P Biogeography Australia and its neighboring islands are home to more than 200 species of marsupials, most of which are found nowhere else in the world
Sugar glider, an omnivore Tasmanian devil, a carnivore Koala, an herbivore Figure 14.22 Order Family Genus Species
Felidae Panthera Panthera pardus (leopard) Mephitis Carnivora Mephitis mephitis (striped skunk) Mustelidae
Lutra Lutra lutra (European otter) Canis latrans (coyote) Phylogeny for some of the members of the order Carnivora Canidae
Canis Canis lupus (wolf) Practical application of phylogenies Growing food Researchers have identified two species of wild grasses that may be maizes closest living relatives
The genomes of these plants may harbor alleles that offer disease resistance or other useful traits that could be transferred into cultivated maize Analogous structures Cladistics diagram or cladogram Iguana Outgroup (reptile) Duck-billed
platypus Hair, mammary glands Gestation Long gestation Kangaroo Beaver Ingroup (mammals) Classification: a work in progress
Phylogenetic trees are hypotheses about evolutionary history Linnaeus divided all known forms of life between the plant and animal kingdoms This two-kingdom system prevailed in biology for over 200 years In the mid-1900s, the two-kingdom system was replaced by a five-kingdom system that
placed all prokaryotes in one kingdom and divided the eukaryotes among four other kingdoms In the late 1900s, molecular studies and cladistics led to the development of a three-domain system, recognizing two domains of prokaryotes (Bacteria and Archaea) and one domain of eukaryotes (Eukarya) The domain Eukarya is currently divided into kingdoms, but the exact number of kingdoms is still under debate
