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Science stack 1

Define species a group of organisms that share similar characteristics - can reproduce among themselves and produce fertile offspring
Define evolution changes in inherited characteristics
Evolution ideas (Darwin) Darwin is the father of natural selection. a.) studied finches on Galapagos Island. b.) all similar to one type of finch . c.) believed the species of finch changed as they competed for food.
Darwin's research led to the theory of- natural selection
Define natural selection organisms with traits best suited to the environment to survive and reproduce. Traits are then passed on to offspring. Unfavorable traits die off with offspring that do not survive.
Define variation inherited trait that makes an individual different from other members of its species.
Variations can come from- mutations
Beneficial mutations are- more likely to be passed on due to natural selection
Explain changes in species changes in species can take a long time to appear. -changes can appear when members of same species move into or out of area. -if small # of individuals are isolated from others variation may appear, that are not present in large population.
What can happen to populations? (explaining changes in species continued...) populations can become so different they cannot breed
Define adaptation variation that increases an organism's chance for survival
Define gradualism (speed of evolution) slow process where one species changes into another
Define punctuated equilibrium (speed of evolution) rapid evolution occurs when individuals mutate and pass on those mutations
Example of punctuated equilibrium i.e. bacteria that are resistant to antibiotics
Define fossils remains or trace of once living organism, usually found in sedimentary rock
List the types of fossils imprint, cast, mold
Define imprint carbon left after organism decays; can harden to rock
Define cast sediments fill in cavity left by decaying organism
Define mold impression of the shape or track of an organism survives
Define relative dating an estimate about the age of the fossil based on location in rock (older fossils are farther down)
Define radiometric dating (half life) amount of time it takes for 1/2 of radioactive material to decay, radioactive material is unstable and decays at set rate, more accurate for determining fossil age
Carbon-14 has a half life of about 5,700; if a fossil had decayed through 2 half-lives, how old is the fossil? 2 x 5,700 = 11,400 -- use the number 2 bc it had 2 half lives, times the age of the fossil- which is 5,700
Carbon-14 has a half life of about 5,700; if a fossil originally has 100 grams of C-14 and now has 25 grams, how old is the fossil? 100 divided by 2 = 50 divided by 2 = 25 -- 100 is the amount of grams (ORIGINALLY), and you have to solve to get to 25. So, find out how many half lives there are until you reach that number (in this case, 25)
Define embryonic structures early in development human embryos and other vertebrates embryos look similar (think of picture example in class)
Define vestigial structures a part that functions in one organism but does not function in another, i.e) tailbone
Define homologous structures structures that are developmentally similar but have different functions, i.e) human arm, cat leg, dolphin flipper, bat wing
Define DNA similar DNA shows common ancestors
Define primates opposable thumbs (grab objects), binocular vison (judge distances), flexible shoulders that rotate (more range of motion). Monkeys, apes and humans are in the same primate group
Define hominids appeared 4-6 million years ago, ate plants and meat; walked upright. are considered relatives of humans- closer than chimpanzees
Example of hominids Australopithecus- "Lucy"- small brain, humanlike brain and teeth; 2.9-3.4 million years ago (after Lucy came)
Homo habilis used simple tools
List the order of evolutionary appearance of hominids Australopithecus, homo habilis, homo erectus, homo sapiens
Homo erectus had larger brain
Homo sapiens appeared 400,00 years ago
What happened 125,000 years ago? Cro-Magnon and Neanderthals appeared (both homo sapiens)
Explain Neanderthals lived in caves, used stone tools, short with small chins, disappeared about 30,000 years ago
Explain Cro-Magnon 10,000-40,000 years ago, more similar and closely related to modern humans, lived in caves, had culture, buried their dead, painted on walls of caves
Created by: areed50