Transcript Chapter #29
Chapter #29 Evolution Chapter 29.1 Notes Adaptation is a trait that makes a living thing able to survive in its surroundings. Natural Selection is the process in which something in a living thing’s surroundings determines if it will or will not survive. • Mutation is a change in DNA. Mutations can be helpful, harmful, or have no effect. • Species is a group of living things that can breed with others of the same species and form fertile offspring. • Fertile being able to reproduce by forming sperm and egg. How new species form? 1. Barrier formed that separated members of a species. 2. Animals live in different environments 3. Groups began to show different traits as a result of natural selection over time 2 groups become 2 different species. Difficulty of defining "species" and identifying particular species • • 1. 2. 3. It is surprisingly difficult to define the word "species" in a way that applies to all naturally occurring organisms, and the debate among biologists about how to define "species" and how to identify actual species is called the species problem. Most textbooks define a species as all the individual organisms of a natural population that generally interbreed at maturity in the wild and whose interbreeding produces fertile offspring. Various parts of this definition are there to exclude some unusual or artificial matings: Those which occur only in captivity (when the animal's normal mating partners may not be available) or as a result of deliberate human action. Animals which may be physically and physiologically capable of mating but do not normally do so because only their normal mating partners perform the courtship rituals or some other behavior "correctly". Animals whose offspring are normally sterile. For example, mules and hinnies have never (so far) produced further offspring when mated with a creature of the same type (a mule with a mule, or a hinny with a hinny). Some hybrids, e.g. mules, hinnies, ligers and tigons, apparently cannot produce offspring when mated with one of their own kind (e.g. a mule with a mule), but sometimes do produce offspring when mated with members of one of the parent species (e.g. a ligon with a lion). Usually in such hybrids the males are sterile, so one could improve the basic textbook definition by changing "... whose interbreeding produces fertile offspring" to "... whose interbreeding produces offspring in which both sexes are normally fertile". • Primates are mammals with eyes that face forward, a well-developed cerebrum, and thumbs that can be used for grasping. • New-world monkeys have a tail that can grasp and nostrils that open upward. Examples howler and spider monkey. • Old-world monkeys can’t grasp with their tails, if they have one, nostrils open downward. Examples baboons, apes, gorillas, chimpanzees. Humanlike forms 3 million years ago. • Homo sapiens is the only human life-form alive today. • Neanderthal man became extinct they were shorter than modern humans and had thicker bones. Chapter 29.2 Notes • 1. 2. 3. 4. Charles Darwin- developed the modern theory of evolution and natural selection. Darwin's Main Points Living things overproduce There is variation among the offspring There is a struggle to survive. Competition is the struggle among living things to get their needs for life. Natural Selection is always taking place. • Evolution is a change in the hereditary features of a group of organisms over time. • Fossils are the remains of once-living things. • Sedimentary rocks- form from layers of mud, sand, and other fine particles. Oldest layer 1 Youngest layer 7 • Vestigial structure is a body part that no longer has a function. Examples third eyelid, appendixes. Work Cited • “Evolution”. May 8, 2007. http://chnm.gmu.edu/resources/essays/images/EvolutionIntelligentD esignClimateChange/evolution1.jpg • “Bee Mutations”. May 8, 2007. http://www.answersingenesis.org/home/area/cfol/images/mutationsfig16.jpg • “Mutation cartoon”. May 8, 2007. http://www.cartoonstock.com/newscartoons/cartoonists/rmc/lowres/r mcn9l.jpg • “Water fowl mutation”. May 8, 2007. http://exoticwaterfowl.com/Quickstart/ImageLib/silver_woods.JPG • “Darwin's Finches”. May 8, 2007. http://www.biologyonline.org/images/darwin_finches.jpg • “Species problem”. May 8, 2007. http://en.wikipedia.org/wiki/Species http://javalab.cs.unibonn.de/research/darwin/images/darwin.jp g • “Darwin”. May 9, 2007. • “Rock Layer”. May 9, 2007. http://updatecenter.britannica.com/eb/imag e?binaryId=63386 • “Vestigial structures”. May 9, 2007. http://www.answersingenesis.org/home/ar ea/magazines/tj/images/v14n2_vestigial_s tructures.gif