The Fossil Record of the Cambrian “Explosion”: Resolving the Tree of Life
Geologist Keith Miller examines the "Cambrian Explosion", a period of rapid evolutionary diversification approximately 575 million years ago, and whether it poses a challenge to evolutionary theory. From the June 2014 issue of Perspectives on Science and Christian Faith from the American Scientific Affiliation.
Hominids Lived Millions of Years Ago, but How Can We Tell? (Videocast)
This BioLogos videocast addresses the age of recently discovered hominid fossils and how scientists are able to obtain those dates.
What scientific evidence do we have about the first humans?
In recent decades, scientists have discovered more about the beginnings of humanity. The fossil record shows a gradual transition over 5 million years ago from chimpanzee-size creatures to hominids with larger brains who walked on two legs. Later hominids used fire and stone tools and had brains as large as modern humans. Fossils of homo sapiens in east Africa date back nearly 200,000 years. Humans developed hearths for fire, stone points for spears and arrows, and cave paintings by 30,000 years ago. By 10,000 years ago, humans had spread throughout the globe. Genetic studies support the same picture. Humans share more DNA with chimpanzees than with any other animal, suggesting that humans and chimps share a relatively recent common ancestor. Also, the same defective genes appear in both humans and chimps, at the same locations in the genome—an observation difficult to explain except by common ancestry. Genetics also tells us that the human population today descended from more than two people. Evolution happens not to individuals but to populations, and the amount of genetic diversity in the gene pool today suggests that the human population was never smaller than several thousand individuals. Yet all humans, of all races, are descended from this group. Humanity is one family.
What is the genetic evidence for evolution?
Darwin developed his theory of evolution by looking at scientific evidence available in the mid-1800s. Since then, the whole field of genetics has developed, adding a powerful independent line of evidence in support of evolution. Genes show how the physical traits of living things are handed down and modified from one generation to the next. By comparing the DNA of many organisms, scientists can map the relationships between species. This map is in remarkable agreement with Darwin’s predictions. The structure of chromosomes and particular genetic sequences point to the conclusion not just of common design, but common descent as well.
Possibilities and Second Chances
In today’s video, Dr. Rick Colling states that evolution is not merely the imposition of death and destruction and survival of the fittest. Rather, it is about second chances.
Beginning with the End in Mind
In today's video, Oxford physicist Ard Louis discusses the famous debate between renowned evolutionary biologists Stephen Jay Gould and Simon Conway Morris over the idea of evolutionary convergence.
Genesis and the Genome
This article provides an overview of genomics evidence for common ancestry and hominid population sizes, and briefly discusses the implications of these lines of evidence for scientific concordist approaches to the Genesis narratives.
Does the Cambrian Explosion pose a challenge to evolution?
The “Cambrian Explosion” refers to the appearance in the fossil record of most major animal body plans about 543 million years ago. The new fossils appear in an interval of 20 million years or less. On evolutionary time scales, 20 million years is a rapid burst that appears to be inconsistent with the gradual pace of evolutionary change. However, rapid changes like this appear at other times in the fossil record, often following times of major extinction. The Cambrian Explosion does present a number of interesting and important research questions. It does not, however, challenge the fundamental correctness of the central thesis of evolution.
What does the fossil record show?
Fossils provide a unique view into the history of life by showing the forms and features of life in the past. Fossils tell us how species have changed across long periods of the Earth’s history. For instance, in 1998, scientists found a fossil showing an animal at the transition from sea creature to land creature. This tetrapod had a hand-like fin, confirming a prediction of evolutionary biology. Though the fossil record does not include every plant and animal that ever lived, it provides substantial evidence for the common descent of life via evolution. The fossil record is a remarkable gift for the study of nature.