Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Natural selection wikipedia , lookup
Punctuated equilibrium wikipedia , lookup
Inclusive fitness wikipedia , lookup
Hologenome theory of evolution wikipedia , lookup
Transitional fossil wikipedia , lookup
Evidence of common descent wikipedia , lookup
Evolutionary history of life wikipedia , lookup
Theistic evolution wikipedia , lookup
Paleontology wikipedia , lookup
The Descent of Man, and Selection in Relation to Sex wikipedia , lookup
Evolution Diversity of Life 1 Lamarck’s Theory of Evolution Use & Disuse - The Size Or Shape Of Body Organs Can Be Changed Due To Use Or Disuse Blacksmiths & Their Sons (muscular arms) Giraffe’s Necks Longer from stretching) 2 3 Voyage of the Beagle Charles Darwin Naturalist 5 Year Voyage around world, HMS Beagle Avid Collector of Flora & Fauna Astounded By Variety of Life 4 The Galapagos Islands Small Group of Islands 1000 km West of South America Very Different Climates Animals On Islands Unique »Tortoises »Iguanas »Finches 5 The Galapagos Islands Finches on the islands resembled a mainland finch Finches had different types of beaks adapted to their type of food gathering 6 7 Darwin’s Observations Patterns of Diversity were shown Unique Adaptations in organisms Species Not Evenly Distributed » Australia, Kangaroos, but No Rabbits » S. America, Llamas 8 Darwin’s Observations Both Living Organisms & Fossils collected Fossils included: »Trilobites »Giant Ground Sloth of South America This species NO longer existed. What had happened to them? 9 Definition • Evolution is the slow , gradual change in a population of organisms over time 10 Darwin’s Observations Left unchecked, the number of organisms of each species will increase exponentially, generation to generation In nature, populations tend to remain stable in size Environmental resources are limited 11 Darwin’s Conclusion • Production of more individuals than can be supported by the environment leads to a struggle for existence among individuals • Only a fraction of offspring survive each generation • Survival of the Fittest 12 Darwin’s Observations • Individuals of a population vary extensively in their characteristics with no two individuals being exactly alike. • Much of this variation between individuals is inheritable. 13 Darwin’s Conclusion • Individuals who inherit characteristics most fit for their environment are likely to leave more offspring than less fit individuals • Called Natural Selection 14 Darwin’s Theory of Evolution •The unequal ability of individuals to survive and reproduce leads to a gradual change in a population, with favorable characteristics accumulating over generations (natural selection) 15 •New species evolve Common Descent with Modification Darwin proposed that organisms descended from common ancestors Idea that organisms change with time, diverging from a common form Caused evolution of new species 16 Natural Selection Driving force for evolution During the struggle for resources, strongest survive & reproduce Idea that at least some of the differences between individuals, which impact their survival and fertility, are inheritable . 17 Evolution By Natural Selection Concepts The Struggle for Existence (compete for food, mates, space, water, etc.) Survival of the Fittest (strongest able to survive and reproduce) Descent with Modification (new species arise from common ancestor replacing less fit species) 18 Survival of the Fittest Fitness – Ability of an Individual To Survive & Reproduce Adaptation – Inherited Characteristic That Increases an Organisms Chance for Survival 19 Survival of the Fittest Adaptations Can Be: – Physical »Speed, Camouflage, Claws, Quills, etc. – Behavioral »Solitary, Herds, Packs, Activity, etc. 20 Survival of the Fittest Fitness Is Central To The Process Of Evolution Individuals With Low Fitness – Die – Produce Few Offspring Survival of the Fittest AKA Natural Selection 21 Survival of the Fittest Key Concept Over Time, Natural Selection Results In Changes In The Inherited Characteristics Of A Population. These Changes Increase A Species Fitness In Its Environment 22 Descent With Modification Takes Place Over Long Periods of Time Natural Selection Can Be Observed As Changes In – Body Structures – Ecological Niches – Habitats 23 Descent With Modification Species Today Look Different From Their Ancestors Each Living Species Has – Descended – With Changes – From Other Species – Over Time 24 Descent With Modification Implies – All Living Organisms Are Related Common Descent – All Species, Living & Extinct, Were Derived From Common Ancestors 25 Evolutionary Time Scales Macroevolution: Long time scale events that create and destroy species. 26 Evolutionary Time Scales Microevolution: Short time scale events (generationto-generation) that change the genotypes and phenotypes of populations 27 Evidence of Evolution Key Concept Darwin Argued That Living Things Have Been Evolving On Earth For Millions of Years. Evidence For This Process Could Be Found In: – The Fossil Record – The Geographical Distribution of Living Species – Homologous Structures of Living Organisms – Similarities In Early Development 28 Fossil Record Earth is Billions of Years Old Fossils In Different Layers of Rock (sedimentary Rock Strata) Showed Evidence Of Gradual Change Over Time 29 Geographic Distribution of Living Species Different Animals On Different Continents But Similar Adaptations To Shared Environments 30 Homologous Body Structures Structures That Have Different Mature Forms But Develop From The Same Embryonic Tissues Strong Evidence That All FourLimbed Animals With Backbones Descended, With Modification, From A Common Ancestor Help Scientist Group Animals 31 Homologous Structures 32 Similarities In Early Development Embryonic Structures Of Different Species Show Significant Similarities Embryo – early stages of vertebrate development 33 Chicken Turtle Human Rat 34