PHYSICAL ANTHROPOLOGY, Exams of Physical anthropology

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PHYSICAL

ANTHROPOLOGY

ANTH

VERSION 1

COLLEGE OF THE CANYONS

Physical Anthropology

An Open Educational Resources Publication by Taft College

Authored and compiled by Sarah Etheredge

Editor: Trudi Radtke

Version 2

2019

Table of Contents

• Physical Anthropology
  • Acknowledgements.....................................................................................................................
  • Acknowledgements.....................................................................................................................
  • Chapter 1: What is Anthropology?
    • The Four Subfields...................................................................................................................
    • The Process of Science
    • The Scientific Method
    • Types of Science
  • Chapter 2: Darwin and the Diversity of Life..............................................................................
    • The Diversity of Life
    • Evolution
    • Charles Darwin and Natural Selection
    • Evidence of Evolution
    • Misconceptions of Evolution
    • Processes and Patterns of Evolution
    • Sources:
  • Chapter 3: Cell biology
    • Cells as Building Blocks
    • DNA
    • Basics of DNA Replication
    • DNA and Protein Synthesis
    • Chromosomes and DNA
    • Cell Division
    • Chromosomal Theory of Inheritance
    • Homologous Recombination
    • Disorders in Chromosome Number
    • Chromosomal Structural Rearrangements
    • Genetics
    • Punnett Squares
    • ABO Blood Type
    • Sources:
  • Chapter 4: Population Genetics
  • Species and the Ability to Reproduce
  • Speciation..............................................................................................................................
  • Allopatric Speciation
  • Adaptive Radiation
  • Reproductive Isolation
  • Genetic Variance
  • Genetic Drift
  • Gene Flow
  • Mutation
  • Additional Forces of Evolution: Nonrandom Mating
  • Environmental Variance........................................................................................................
  • Hardy-Weinberg Equation to Test for Evolution
  • Hardy-Weinberg Equilibrium
  • Sources:
• Chapter 5 – Human Variation
  • The Concept of Race
  • Introduction
  • Reason for Race, Not Justification
  • Evolution of Skin Color
  • Sex and Gender
  • Genetics of Homosexuality, Transgender and Intersex
  • Human Growth and Development – What Can Bones Tell Us?
  • Young or Old?........................................................................................................................
  • Clues in the Pelvis
  • Ancestry
  • Human or Non-Human?
  • Forensic Anthropology
  • Forensic Facial Reconstruction
  • A Modern Forensic Case File.................................................................................................
  • Sources:
• Chapter 6 – The Primates
  • Introduction
  • From the Beginning: Evolution of Mammals
  • Early Mammals: Monotremes
  • Marsupials
  • Lactation
  • Body Temperature
  • Placental Mammals.............................................................................................................
  • Taxonomy............................................................................................................................
  • Phylogenetic Trees
  • Order Primates
  • Social Behavior and Intelligence
  • Studying Primates
  • Sources:
• Chapter 7 – Primate Intelligence and Conservation
  • Vocal Communication and Language
  • Primate Brain
  • Conservation of Biodiversity
  • Threats to Primates.............................................................................................................
  • Early Life History Theories: K-selected and r-selected Species
  • Modern Life History Theory
  • Types of Natural Resources:
  • The Role of Captive Breeding..............................................................................................
  • Water Conservation
  • Sources:
• Chapter 8—Fossils and Early Primates
  • Fossils
  • Evolution and the Tree of Life.............................................................................................
  • Bipedalism
  • Brain Size
  • Free Hands
  • Tool Use
  • Chronology and dating methods
  • Early Primate Evolution.......................................................................................................
  • Sources:
• Chapter 9—Bipedalism and Human Evolution
  • What is a Hominin?
  • Evolution of Bipedalism
  • Bipedal Anatomy
  • Very Early Hominins
  • Earliest Bipeds
  • Early Hominins: Genus Australopithecus............................................................................
  • Kenyanthropus platyops
  • Australopithecus gahri
  • Australopithecus sediba......................................................................................................
  • A Dead End: Genus Paranthropus
  • Sources:
• Chapter 10—Genus Homo Early Members.............................................................................
  • Early Hominins: Genus Homo
  • New Discovery: Homo naledi
  • Sources:
• Chapter 11—Genus Homo and Homo sapiens
  • Homo heidelbergensis
  • Denisovans
  • Homo Neanderthalensis
  • Humans: Homo sapiens
  • Sources:
• Chapter 12— Homo sapiens, our History and our Future
  • Culture/Behavior.................................................................................................................
  • The Beringians.....................................................................................................................
  • Are Humans Still Evolving?
  • Agriculture and its Effect on Humans
  • Evolution and Human Health: Balanced Polymorphisms
  • Humans’ Future: Climate Change
  • Sources:

Acknowledgements

We would like to extend appreciation to the following people and organizations

for allowing this textbook to be created:

California Community Colleges Chancellor’s Office

Chancellor Diane Van Hook

Santa Clarita Community College District

College of the Canyons Distance Learning Office

In providing content for this textbook, the following professionals and sources

were invaluable:

Major sources of content:

The American Anthropological Association

Lumens Learning

OpenStax

Faculty involved:

Compiled by

Sarah Etheridge-Criswell MA, PHD

Special Thank You to Brian Barr & Trudi Radtke for helping with formatting, editing, readability, and aesthetics.

The contents of this textbook were developed under the Title V grant from the Department of Education (Award #P031S140092). However, those contents do not necessarily represent the policy of the Department of Education, and you should not assume endorsement by the Federal Government.

Unless otherwise noted, the content in this textbook is licensed under CC BY 4.

Biological Anthropology

Biological anthropologists seek to understand how humans adapt to different environments, what causes disease and early death, and how humans evolved from other animals. To do this, they study humans (living and dead), other primates such as monkeys and apes, and human ancestors (fossils). They are also interested in how biology and culture work together to shape our lives. They are interested in explaining the similarities and differences that are found among humans across the world. Through this work, biological anthropologists have shown that, while humans do vary in their biology and behavior, they are more similar to one another than different.

Cultural Anthropology

Sociocultural anthropologists explore how people in different places live and understand the world around them. They want to know what people think is important and the rules they make about how they should interact with one another. Even within one country or society, people may disagree about how they should speak, dress, eat, or treat others. Anthropologists want to listen to all voices and viewpoints in order to understand how societies vary and what they have in common. Sociocultural anthropologists often find that the best way to learn about diverse peoples and cultures is to spend time living among them. They try to understand the perspectives, practices, and social organization of other groups whose values and lifeways may be very different from their own. The knowledge they gain can enrich human understanding on a broader level.

Linguistic Anthropology

Linguistic anthropologists study the many ways people communicate across the globe. They are interested in how language is linked to how we see the world and how we relate to each other. This can mean looking at how language works in all its different forms, and how it changes over time. It also means looking at what we believe about language and communication, and how we use language in our lives. This includes the ways we use language to build and share meaning, to form or change identities, and to make or change relations of power. For linguistic anthropologists, language and communication are keys to how we make society and culture.

Applied and Practicing Anthropology

Applied or practicing anthropologists are an important part of anthropology. Each of the four subfields of anthropology can be applied. Applied anthropologists work to solve real world problems by using anthropological methods and ideas. For example, they may work in local communities helping to solve problems related to health, education, or the environment.

They might also work for museums or national or state parks helping to interpret history. They might work for local, state or federal governments or for non-profit organizations. Others may work for businesses, like retail stores or software and technology companies, to learn more about how people use products or technology in their daily lives. Some work in the USA while others work internationally. Jobs for applied anthropologists have shown strong growth in the recent past with more and more opportunities becoming available as demand grows for their valuable skill sets.

The Process of Science

Physical or biological anthropology uses biology as a foundation. Biological anthropology is a science, but what exactly is science? What does the study of biology share with other scientific disciplines? Science (from the Latin scientia , meaning “knowledge”) can be defined as knowledge that covers general truths or the operation of general laws, especially when acquired and tested by the scientific method. It becomes clear from this definition that the application of the scientific method plays a major role in science. The scientific method is a method of research with defined steps that include experiments and careful observation.

The steps of the scientific method will be examined in detail later, but one of the most important aspects of this method is the testing of hypotheses by means of repeatable experiments. A hypothesis is a suggested explanation for an event, which can be tested. Although using the scientific method is inherent to science, it is inadequate in determining what science is. This is because it is relatively easy to apply the scientific method to disciplines such as physics and chemistry, but when it comes to disciplines like archaeology, psychology, and geology, the scientific method becomes less applicable as it becomes more difficult to repeat experiments.

These areas of study are still sciences, however. Consider archeology—even though one cannot perform repeatable experiments, hypotheses may still be supported. For instance, an archeologist can hypothesize that an ancient culture existed based on finding a piece of pottery. Further hypotheses could be made about various characteristics of this culture, and these hypotheses may be found to be correct or false through continued support or contradictions from other findings. A hypothesis may become a verified theory. A theory is a tested and confirmed explanation for observations or phenomena. Science may be better defined as fields of study that attempt to comprehend the nature of the universe.

Testing a Hypothesis

A valid hypothesis must be testable. It should also be falsifiable , meaning that it can be disproven by experimental results. Importantly, science does not claim to “prove” anything because scientific understandings are always subject to modification with further information. This step—openness to disproving ideas—is what distinguishes sciences from non-sciences. The presence of the supernatural, for instance, is neither testable nor falsifiable. To test a hypothesis, a researcher will conduct one or more experiments designed to eliminate one or more of the hypotheses.

Each experiment will have one or more variables and one or more controls. A variable is any part of the experiment that can vary or change during the experiment. The control group contains every feature of the experimental group except it is not given the manipulation that is hypothesized about. Therefore, if the results of the experimental group differ from the control group, the difference must be due to the hypothesized manipulation, rather than some outside factor. Look for the variables and controls in the examples that follow.

To test the first hypothesis, the student would find out if the air conditioning is on. If the air conditioning is turned on but does not work, there should be another reason, and this hypothesis should be rejected. To test the second hypothesis, the student could check if the lights in the classroom are functional. If so, there is no power failure and this hypothesis should be rejected. Each hypothesis should be tested by carrying out appropriate experiments. Be aware that rejecting one hypothesis does not determine whether or not the other hypotheses can be accepted; it simply eliminates one hypothesis that is not valid. Using the scientific method, the hypotheses that are inconsistent with experimental data are rejected.

While this “warm classroom” example is based on observational results, other hypotheses and experiments might have clearer controls. For instance, a student might attend class on Monday and realize she had difficulty concentrating on the lecture. One observation to explain this occurrence might be, “When I eat breakfast before class, I am better able to pay attention.” The student could then design an experiment with a control to test this hypothesis.

In hypothesis-based science, specific results are predicted from a general premise. This type of reasoning is called deductive reasoning : deduction proceeds from the general to the particular. But the reverse of the process is also possible: sometimes, scientists reach a general conclusion from a number of specific observations. This type of reasoning is called inductive reasoning, and it proceeds from the particular to the general. Inductive and deductive reasoning are often used in tandem to advance scientific knowledge.

Figure 2. A Graphical illustration of the scientific method

The scientific method consists of a series of well-defined steps. If a hypothesis is not supported by experimental data, a new hypothesis can be proposed.

In the example figure, the scientific method is used to solve an everyday problem. Order the scientific method steps (numbered items) with the process of solving the everyday problem (lettered items). Based on the results of the experiment, is the hypothesis correct? If it is incorrect, propose some alternative hypotheses.

1. Observation
2. Question
3. Hypothesis (answer)
4. Prediction
5. Experiment
6. Result

Types of Science

Basic science or “pure” science seeks to expand knowledge regardless of the short-term application of that knowledge. It is not focused on developing a product or a service of immediate public or commercial value. The immediate goal of basic science is knowledge for knowledge’s sake, though this does not mean that, in the end, it may not result in a practical application.

The Human Genome Project was a 13-year collaborative effort among researchers working in several different fields of science. The project, which sequenced the entire human genome, was completed in 2003. (credit: the U.S. Department of Energy Genome Programs (http://genomics.energy.gov))

Citation: A link to the American Anthropological Association webpage

http://www.ornl.gov/hgmis (Genome seal)

Chapter 2: Darwin and the Diversity of Life

The Diversity of Life

The fact that biology, as a science, has such a broad scope has to do with the tremendous diversity of life on earth. The source of this diversity is evolution , the process of gradual change during which new species arise from older species. Evolutionary biologists study the evolution of living things in everything from the microscopic world to ecosystems.

This phylogenetic tree was constructed by microbiologist Carl Woese using data obtained from sequencing ribosomal RNA genes. The tree shows the separation of living organisms into three domains: Bacteria, Archaea, and Eukarya. Bacteria and Archaea are prokaryotes, single-celled organisms lacking intracellular organelles

Figure 1: The Phylogenic tree credit: Eric Gaba; NASA Astrobiology Institute

The evolution of various life forms on Earth can be summarized in a phylogenetic tree. A phylogenetic tree is a diagram showing the evolutionary relationships among biological species based on similarities and differences in genetic or physical traits or both. A phylogenetic tree is composed of nodes and branches. The internal nodes represent ancestors and are points in evolution when, based on scientific evidence, an ancestor is thought to have diverged to form two new species. The length of each branch is proportional to the time elapsed since the

Figure 2: Darwin observed that beak shape varies among finch species. He postulated that the beak of an ancestral species had adapted over time to equip the finches to acquire different food sources.

On these islands, Darwin observed species of organisms on different islands that were clearly similar, yet had distinct differences. For example, the ground finches inhabiting the Galápagos Islands comprised several species with a unique beak shape. The species on the islands had a graded series of beak sizes and shapes with very small differences between the most similar. He observed that these finches closely resembled another finch species on the mainland of South America. Darwin imagined that the island species might be species modified from one of the original mainland species. Upon further study, he realized that the varied beaks of each finch helped the birds acquire a specific type of food. For example, seed-eating finches had stronger, thicker beaks for breaking seeds, and insect-eating finches had spear-like beaks for stabbing their prey. Darwin observed that beak shape varies among finch species. He postulated that the beak of an ancestral species had adapted over time to equip the finches to acquire different food sources.

Wallace and Darwin both observed similar patterns in other organisms and they independently developed the same explanation for how and why such changes could take place. Darwin called this mechanism natural selection. Natural selection , also known as “survival of the fittest,” is the more prolific reproduction of individuals with favorable traits that survive environmental change because of those traits; this leads to evolutionary change.

For example, a population of giant tortoises found in the Galapagos Archipelago was observed by Darwin to have longer necks than those that lived on other islands with dry lowlands. These tortoises were “selected” because they could reach more leaves and access more food than those with short necks. In times of drought when fewer leaves would be available, those that could reach more leaves had a better chance to eat and survive than those that couldn’t reach the food source. Consequently, long-necked tortoises would be more likely to be reproductively successful and pass the long-necked trait to their offspring. Over time, only long-necked tortoises would be present in the population.

Figure 3: Both (a) Charles Darwin and (b) Alfred Wallace wrote scientific papers on natural selection that were presented together before the Linnean Society in 1858.

Natural selection, Darwin argued, was an inevitable outcome of three principles that operated in nature.

 First, most characteristics of organisms are inherited, or passed from parent to offspring. Although no one, including Darwin and Wallace, knew how this happened at the time, it was a common understanding.  Second, more offspring are produced than are able to survive, so resources for survival and reproduction are limited. The capacity for reproduction in all organisms outstrips the availability of resources to support their numbers. Thus, there is competition for those resources in each generation. Both Darwin and Wallace’s understanding of this principle came from reading an essay by the economist Thomas Malthus who discussed this principle in relation to human populations.  Third, offspring vary among each other in regard to their characteristics and those variations are inherited. Darwin and Wallace reasoned that offspring with inherited characteristics which allow them to best compete for limited resources will survive and have more offspring than those individuals with variations that are less able to compete. Because characteristics are inherited, these traits will be better represented in the next generation. This will lead to change in populations over generations in a process that Darwin called descent with modification. Ultimately, natural selection leads to greater adaptation of the population to its local environment; it is the only mechanism known for adaptive evolution.

Papers by Darwin and Wallace presenting the idea of natural selection were read together in 1858 before the Linnean Society in London. The following year Darwin’s book, On the Origin of Species, was published. His book outlined in considerable detail his arguments for evolution by