Understanding Evolution and Species Classification
Explore key concepts such as microevolution, macroevolution, species definition, population genetics, and the development of new species through variation over time. Learn about the importance of isolation in species formation, the hierarchical classification system, and the six kingdoms of life.
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charles_darwin_l C21_GenePool_2 Evolution = change/time Change of what? Inherited characteristics two types 1. Microevolution refers to change in the gene pool of a population 2. Macroevolution refers to speciation
Species Concept What is a species? Definition = a group of organisms that are capable of mating with one another in nature to produce fertile, viable (living), offspring
POPULATION GENETICS Def:study of changes in the genetic composition of populations What is a population? Def:organisms of the same species living together in the same area/environment NOTE: If organisms live in the same region, they experience same environmental pressures from natural selection!
IC8_page9 Peppered Moth moth_fig1 IN00601_
How does a species develop? Species develop from other species (ancestor) through variation over time! Variation = differences within a species Arise due to mutation, errors in DNA replication, meiosis, etc.
Does variation alone lead to a new species? No Isolation! When groups separate they change from one another due to different environmental pressures! What happens when 2 best friends go away to different colleges? s_aberts
Classification We classify based on a Hierarchical System! Big, general Small, specific King Phillip Came Over For Great Spaghetti Kingdom Phylum Class Order Family Genus Species
Kingdoms of Life Until recently scientists recognized 5 kingdoms: Monera, Protista, Fungi, Plantae, & Animalia Monera was split into two: archaebacteria and eubacteria Now scientists use a six kingdom model: 1. Eubacteria 2. Archaebacteria 3. Protista 4. Fungi 5. Plantae 6. Animalia
Example! Human Classification Kingdom Phylum Class Order Family Genus Species Animalia Chordata Mammalia Primate Hominidae Homo Sapien little_person
Binomial Nomenclature Carolus Linnaeus - Taxonomy Scientific Name vs. Common Name Always written in italics First word is capitalized = genus Second word is lowercase = species Example: White Pine Pinus strobus Dog dog_tag1 Canus familaris
History of Evolutionary Theory Portrait-of-Jean-Baptiste-de-Monet-Chevalier-de-Lamarck-1802-03-Giclee-Print-C12258838 Jean Baptiste Lamarck Theory of use & disuse Individual organisms change in response to their environment and pass this acquired trait to their offspring.
History of Evolutionary Theory DARWIN charles-darwin-8221 Charles Darwin Early to Mid 1800 s Age 22 left England aboard the HMS Beagle Galapagos Islands, South America, Africa, and Australia darwin testDarwin
originofspeciesxq5 Darwin s Theory 1859 On Origin of the Species Theory of Natural Selection survival and reproduction of organisms that are best suited to their environment sphinx_moth
Theory of Natural Selection Main Points 1. Populations tend to grow & overpopulate 2. Resource competition resources are limited 3. Inheritable Variation exists among populations that makes some individuals more fit than others. 4. Those individuals with variation that allows them to survive better will reproduce more often. Their genes & traits are passed onto offspring, causing these genes & traits to increase in proportion in the population.
Evidence for Evolution Fossil Record Comparative Anatomy Molecular Biology Biogeography Embryology
Fossil Record Remains of plants or animals that were once living Used to: reveal the existence of species that came before & are now extinct (Life has changed over time!) Develop relationships Rate of Evolutionary Change Incomplete Why?
Comparative Anatomy Study of different structures used to develop relationships Homologous, Analogous, Vestigial
Molecular Biology Study differences in DNA & amino acid sequences Those organisms most closely related have the most similarities. koalaalb Biogeography Movement of continents continental drift Trace species back to splits in populations due to continental drift
Embryology Study of similarities during embryo development
What can we conclude from all of this evidence? Descent with Modification! New life forms appeared to be modifications of fossil forms found in similar geographic areas. Implies that modern life forms are descendents of older life forms that have changed slowly over time. Q: What made them change?
Coevolution Change or Evolution of 1 species affects the evolution of another. Ex: Predator Prey (arms race) Convergent Evolution Occurs when environmental pressures act similarly to unrelated species. Example: whale & shark Divergent Evolution 2 or more related species become increasingly different Related species are introduced into different environments.
Divergent Evolution Adaptive Radiation Rapid increase in # of species image?id=54911rendTypeId=4
