Our Origins: Discovering Physical Anthropology (Third Edition)
Clark Spencer Larsen
Format: PDF / Kindle (mobi) / ePub
Gives students the tools they need to see the Big Picture.
The Third Edition of this best-selling text now includes an update to the evolutionary primate taxonomy and even more tools to help students grasp the major concepts in physical anthropology―including new, photorealistic art.
foods (Figure 1.4). The first development represents the most profound physical difference between humans and other animals, namely the manner in which we get around: we are committed to bipedalism, that is, walking on two feet. The next development was the loss of a large, honing canine tooth, like the one that apes typically use to shred their food (mostly plants) to the simple nonhoning canine with which we simply process food. Our ancestors’ honing canine disappeared because they acquired the
individual scientists. However, many more identifications and other information came from the Human Genome Project (1990–2003), an international effort in which hundreds of scientists sought to discover and map all the genes. In 2004, the genome map that resulted from this massive research was published in the British journal Nature. Contrary to expectations that 100,000 genes are responsible for the human body’s proteins, the map revealed that less than a quarter of that figure—between 20,000
a chain of amino acids. A chain of these peptide bonds is called a polypeptide. Although a single polypeptide may function as a protein, in many cases multiple polypeptides must bind together and fold into a three-dimensional structure to form a functional protein. For example, hemoglobin, a molecule found on the surface of red blood cells, is comprised of two pairs of polypeptide chains. Once the protein has formed, it breaks away from the tRNA and commences with its task, either structural or
to determine. ■ Most physical characteristics are determined by more than one gene (polygenic), and some genes can have multiple effects (pleiotropy). A wwnorton.com/studyspace KEY TERMS adenine adenosine triphosphate (ATP) amino acids antibodies anticodons antigens autosomes coding DNA codominance codons complementary bases cross-over 82 cytoplasm cytosine diploid essential amino acids eukaryotes free-floating nucleotides gametes genome genomics guanine haploid haplogroups Chapter 3
water produced by the eccrine glands, which are located over the entire body’s surface. Evaporation of the thin layer of water on the skin results in cooling of the surface. Humans can sweat a remarkably high volume of water, and this physiological process is central to humans’ long-term functional adaptation to heat. Sweating is less effective in areas of the body having a dense hair cover than in areas of the body having little or no hair. This relationship suggests that sweating evolved as a