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Rediscovering Biology: Molecular to Global Perspectives

Human Evolution

Human evolution has been a hotly debated field of study, now aided by molecular data and new fossil finds. This unit examines concepts such as the Mitochondrial Eve, Africa as the point of origin of our species, the human replacement of all other hominids, and the significant impact these vents have had on the genes of modern humans.

ONLINE TEXTBOOK
The online textbook chapters support and extend the content of each video. The Web version can be viewed as a full chapter or as individual sub-sections, and includes links to glossary terms and other related material.

ANIMATIONS & IMAGES
Explore the archive of animations, images and figures from the videos and online textbook. All of the images can be viewed online or downloaded as jpg files.

EXPERT INTERVIEW TRANSCRIPTS
Read profiles of the expert scientists featured in the video and find the complete transcripts of the interviews conducted for this unit.
Kari Stefansson, M.D.
Ian Tattersall, Ph.D.
Ajit Varki, M.D.
Christopher Wills, Ph.D.

Chapter Contents

Introduction
New Fossils
What Does DNA Tell Us About Our Position Among the Apes?
Variation Within and Among Human Populations
Out of Africa?
Neaderthals in Our Gene Pool?
Human Genetic Variation and Disease
Malaria, Sickle Cell Anemia, and Balancing Selection
Resistance to HIV
The Genetics of Asthma, a Complex Disease
Our History, Our Future

Unit Glossary

Balancing selection
Selection that actively maintains more than one variant of a gene in a population.

Chemokine
A chemical signal that attracts white blood cells to infected parts of the body.

Chemokine receptor
Protein associated with the membranes of white blood cells that chemokines can attach to.

Gene tree
A representation of the evolutionary history of a particular gene or DNA sequence.

Hominids
All members of the lineage that diverged humans; includes Homo sapiens and all extinct species since it split from the common ancestor of humans and apes.

Mitochondrial Eve
The woman who possessed the most recent common ancestor of all mitochondrial DNA variants currently in the human population.

Molecular clock
The hypothesis that, within lineages, DNA sequences of a particular gene will evolve in a roughly clock-like manner; that is, approximately as a linear function of time.

Molecular clock
The hypothesis that, within lineages, DNA sequences of a particular gene will evolve in a roughly clock-like manner; that is, approximately as a linear function of time.

“Out of Africa” (replacement) hypothesis
The hypothesis that postulates that modern Homo sapiens spread out of Africa into Europe and Asia, and replaced archaic Homo sapiens living in those regions; contrasted with the Multi-Regional hypothesis.

Species tree
A representation of the evolutionary relationships of different species.

 

Unit Animations

  • Hominoid Family Tree
    Family tree of hominoids, including the apes and man.
    View Animation Still
  • Human Fossil Bush
    The Hominid Family Bush made up of modern humans, their ancestors, and their now-extinct relatives.
    View Animation Still
  • Human Migration Hypotheses
    Most scientists agree that an early hominid species evolved in Africa and spread across the Old World. After that, there is still some debate between the Multiregional hypothesis and the Out of Africa, or Replacement hypothesis as to how modern humans came to evolve and populate the globe.
    View Quicktime Movie
  • Mitochondrial DNA
    A 3-D animation of the way that a zygote receives nuclear, or genomic, DNA from both parents (sperm and egg cells) but inherits mitochondrial DNA only from the mother.
    View Quicktime Movie
  • Mitochondrial Eve
    This shows how one female ancestor passed on her mitochondrial DNA to everyone living today. This woman, called “Mitochondrial Eve,” probably lived only 200,000-300,000 years ago.
    View Quicktime Movie
  • Regulatory Hypothesis
    This animation illustrates the experiments that Ajit Varki, Wolf Enard, and Svente Paabo carried out to compare the gene expression between chimpanzees, humans, and an outgroup, the Rhesus monkey. While gene expression was similar between humans and chimps in the liver and blood, they showed very different patterns of gene expression in the brain.
    View Quicktime Movie

Related Resources

Books
Freeman, S., and J. C. Herron. 2001. Evolutionary analysis. 2d ed. Upper Sadle River, NJ: Prentice Hall.
An excellent inquiry-based college-level textbook on evolution.

Ridley, M. 2000. Genome: The autobiography of our species in 23 chapters. New York: HarperCollins.
A series of essays (one for each chromosome in the human genome) that discuss various aspects of human genetics and evolution.

Willis, C. 1998. Children of prometheus: The accelerating pace of human evolution.
In this semi-popular book, Willis discusses the ways in which humans are still evolving.

Series Directory

Rediscovering Biology: Molecular to Global Perspectives

Credits

Produced by Oregon Public Broadcasting. 2003.
  • ISBN: 1-57680-733-9