C) It includes transitional forms with progressively specialized teeth. E) the maintenance of the previously existing ocean currents and wind patterns.27) The major evolutionary episode corresponding most closely in time with the formation of Pangaea was the A) Cambrian explosion. A) He would have placed them all in the same species. A) Natural selection and sexual selection can work at cross-purposes to each other. When they had become sufficiently large, these extensions became useful for gliding through the air, and selection later refined them as flight-producing wings. This trend toward species that perform live birth in a particular environment is an example of A) natural selection. Both species had large brains and advanced intellects.

accommodating employees - Common isotopes for radiometric dating

E) It includes a series that shows the gradual change of scales into fur.14) If a fossil is encased in a stratum of sedimentary rock without any strata of igneous rock (for example, lava, volcanic ash) nearby, then it should be A) easy to determine the absolute age of the fossil, because the radioisotopes in the sediments will not have been "reset" by the heat of the igneous rocks. C) He would have placed them in more species than modern botanists do. It, and the loss of limbs by snakes, are an example of similar adaptations to a similar environment. A) species selection B) uniformitarianism C) sexual selection D) convergent evolution39) The existence of evolutionary trends, such as increasing body sizes among horse species, is evidence that A) a larger volume-to-surface area ratio is beneficial to all mammals. C) evolution always tends toward increased complexity or increased size.

B) easy to determine the absolute age of the fossil, because the igneous rocks will not have physically obstructed the deposition of sediment of a single age next to the fossil. D) He would have used evolutionary relatedness as the primary criterion for their classification.29) An organism has a relatively large number of Hox genes in its genome. A) These genes are fundamental, and are expressed in all cells of the organism. D) in particular environments, similar adaptations can be beneficial in more than one species.

D) Early Earth's atmosphere had significant quantities of ozone.3) What is true of the amino acids that might have been delivered to Earth within carbonaceous chondrites?

A) They had the same proportion of L and D isomers as Earth does today. formation of DNA-based genetic systems A) I, II, III, IV B) I, III, II, IV C) II, III, I, IV D) II, III, IV, I5) Which of the following is a defining characteristic that all protobionts had in common?

D) They were delivered in the form of polypeptides.4) Which of the following is the correct sequence of events in the origin of life? B) earlier genetic systems than those based on DNA. D) the delivery of organic matter to Earth by meteors and comets.

E) the endosymbiotic origin of mitochondria and chloroplasts.8) Several scientific laboratories across the globe are involved in research concerning the origin of life on Earth.

9) If natural selection in a particular environment favored genetic systems that permitted the production of daughter "cells" that were genetically dissimilar from the mother "cells," then one should expect selection for which of the following? polynucleotide polymerase with low mismatch error rates II.

polynucleotide polymerases without proofreading capability III. batteries of efficient polynucleotide repair enzymes IV.

E) prevent the formation of an ozone layer.16) Which of the following statements provides the strongest evidence that prokaryotes evolved before eukaryotes? B) The meteorites that have struck Earth contain fossils only of prokaryotes. Adult female bagworm moths are larval in appearance; they lack the wings and other structures of the adult male and instead retain the appearance of a caterpillar even though they are sexually mature and can lay eggs within the bag. D) the feathers were plucked from the bodies of other adults to provide nest-building materials. At the arrow labeled "I" (the rift valley), the igneous rock of the sea floor is so young that it can be accurately dated using carbon-14 dating. The figure represents a cross section of the sea floor through a mid-ocean rift valley, with alternating patches of black and white indicating sea floor with reversed magnetic polarities.