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Knowledge and Skills Statement

Science concepts--biological evolution. The student knows evolutionary theory is a scientific explanation for the unity and diversity of life that has multiple lines of evidence.

Engaging in this student expectation may help students become aware that there is a common genetic code for all life on Earth, which is why molecular homologies work and are the strongest form of evidence. The degree to which two proteins share the same amino acid or codon sequence can indicate how closely related the organisms are. Scientists use molecular homologies to create phylogenetic trees of various complexities and depth. For example, DNA helps determine the number of domains and kingdoms.

The fossil record provides documentation of species evolution over geological time. The fossil record can be used to show anatomical homologies and biogeographical relationships between species. Biogeography can be used to study both extant and extinct species. Studying the physical distribution of species and populations across the landscape can provide clues about how and when species have evolved or may evolve.

structures that are the same between different organisms

anatomical similarities between animals during the early embryo stages

the theory in biology postulating that the various types of plants, animals, and other living things on Earth have their origin in other preexisting types and that the distinguishable differences are due to modifications in successive generations

the history of life as documented by fossils; the remains or imprints of organisms from earlier geological periods preserved in sedimentary rock

the similarity that two organisms share at the genetic level for a particular molecule

Research

Hurst, Laurence D. "Showcasing the Evidence for Evolution." Nature 461, no. 7264 (October 2009): 596. https://www.nature.com/articles/461596a

Summary:  I am usually reluctant to claim anything to be a 'fact'. Likewise, I shy away from the word 'proof ' beyond the certainties of mathematics. But, as Richard Dawkins makes plain in The Greatest Show on Earth, cautious scientists like me should get off the fence. Our enterprise has established facts and we should have the confidence to say so. Evolution is one such fact, and the evidence for it is laid out in two new books by Dawkins and Carl Zimmer.

Research

Spoor, F., S. Bajpai, S. T. Hussain, K. Kumar & J. G. M. Thewissen. "Vestibular Evidence for the Evolution of Aquatic Behaviour in Early Cetaceans." Nature 417, no. 6885 (May 2002): 163-166. https://doi.org/10.1038/417163a

Summary:  Early cetaceans evolved from terrestrial quadrupeds to obligate swimmers, a change that is traditionally studied by functional analysis of the postcranial skeleton. Here we assess the evolution of cetacean locomotor behavior from an independent perspective by looking at the semicircular canal system, one of the main sense organs involved in the neural control of locomotion. We hypothesize that the unparalleled modification of the semicircular canal system represented a key ‘point of no return’ event in early cetacean evolution, leading to full independence from life on land.