Download ASTR101 Unit 13 Assessment Answer Key 1. The Miller

ASTR101
Unit 13 Assessment
Answer Key
1. The Miller-Urey experiment, in which simple inorganic molecules and an energy
source produced a variety of organic compounds including amino acids, the building
blocks of proteins, was the first to demonstrate chemical evolution. Since then, many
similar experiments have been done producing other biologically significant organic
molecules. The presence of organic molecules in meteorites and in the interstellar
medium is also evidence for chemical evolution. Experiments also show that under
certain conditions, organic molecules can spontaneously form cell-like structures.
2. The existence of datable fossils is the primary evidence for evolution. Evolution
requires that the morphological changes that lead from the most primitive species of a
particular type of organism to the present must occur in chronological order. Fossil
evidence is always consistent with this requirement. The existence of vestigial organs
is also evidence for evolution. For example, hips and leg bones in whales show that the
ancestors of whales once walked on land.
3. Vertebrates, amphibians, reptiles, mammals, primates.
4. Australopithecus afarensis, Australopithecus africanus, Homo habilis, and Homo
erectus are the best known. The major trends are bipedalism, increase in height,
increase in cranial capacity, reduction of tooth size, and a flattening of the face.
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