From The Archives: Where are the Transitional Fossils?
From the archives: A common argument leveled against the theory of evolution is that scientists have not been able to produce transitional fossils that show the change of one species into another. In this podcast, we address a common misconception about what transitional fossils actually are.
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.
Evolution: What We Know and What We Don't
This entry was originally posted on February 17, 2010. In this video conversation, Jeff Schloss makes the observation that when we use the term “evolution”, it is not always exactly clear what we are actually discussing unless we denote the intended usage.
What evidence do we have for evolution besides fossils and genes?
Scientists have found multiple lines of evidence for evolution, not just one or two. These types of evidence are independent of each other, coming from sources as different as ancient fossils and modern genetics labs. Evidence also comes from comparing the anatomy of creatures living today. All creatures with four limbs (whether mammals, birds, or reptiles) have the same bone structure in each limb, pointing to their descent from a common ancestor. More evidence comes from biogeography. Isolated islands are missing common species found on the mainland, but are filled with many unique species that can be related by a common ancestor. Finally, evidence comes from embryonic development. As an embryo of a mammal grows, its heart develops through stages similar to fish, amphibians, and reptiles. God’s creation declares the history of life in many different ways. All these ways are pointing to a consistent picture of God creating through evolution.
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.
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.
Evolution: What We Know and What We Don't
In this video conversation, Jeff Schloss makes the observation that when we use the term “evolution”, it is not always exactly clear what we are actually discussing unless we denote the intended usage.
A Deeper Pattern (Video)
In this video interview, evolutionary biologist Simon Conway Morris discusses evolutionary convergence, the emergence of identical biological traits through unrelated evolutionary lineages. He gives two examples in the video -- the camera eye and saber toothed cats.
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.
How can evolution account for the complexity of life on earth today?
A complex biological structure with many interacting parts might appear, at first glance, as if it were originally created in its present form with all its interlocking components fully formed and intact. It doesn’t seem possible that they developed step by step via biological evolution. In Darwin’s Black Box, Michael Behe introduces a term that he and other proponents of Intelligent Design use for this concept: irreducible complexity.
Isn’t the origin of life highly improbable?
From all we know about the state of the Earth 3 to 4 billion years ago and what we know about the complexity of the building blocks of life — DNA, RNA, amino acids, sugars — no entirely plausible hypothesis for the spontaneous origin of life has been found. But this does not mean that supernatural activity is the only possible explanation.
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.
What is evolution?
Evolution is the biological model for the history of life on Earth. While some consider evolution to be equivalent to atheism, BioLogos sees evolution as a description of how God created all life. Evolution refers to descent with modification. Small modifications occur at the genetic level (in DNA) with each generation, and these genetic changes can affect how the creature interacts with its environment. Over time, accumulation of these genetic changes can alter the characteristics of the whole population, and a new species appears. Major changes in life forms take place by the same mechanism but over even longer periods of time. All life today can be traced back to a common ancestor some 3.85 billion years ago.