Questions Categorized as "Scientific Evidence"

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How are the ages of the Earth and universe calculated?

Many independent measurements have established that the Earth and the universe are billions of years old.  Geologists have found annual layers in glaciers that can be counted back 740,000 years.  Using the known rate of change in radio-active elements (radiometric dating), some Earth rocks have been shown to be billions of years old, while the oldest solar system rocks are dated at 4.6 billion years.  Astronomers use the distance to galaxies and the speed of light to calculate that the light has been traveling for billions of years.  The expansion of the universe gives an age for the universe as a whole: 13.7 billion years old.

(Updated April 16, 2012)

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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.

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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.

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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.

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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.

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