Current Events

  • Irish Chronicles Document Links Between Volcanoes and Weather
    A study of over 40,000 written entries in Irish Annals and ice core measurements shows a strong corr...Read more

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    Irish Chronicles Document Links Between Volcanoes and Weather

    A study of over 40,000 written entries in Irish Annals and ice core measurements shows a strong correlation between the occurrence of volcanic eruptions and extreme cold weather in Ireland over a 1200 year period. Data analyzed in this study cover the period from 431 to 1649, during which time up to 48 volcanic eruptions are identified in Greenland ice core records through deposition of volcanic sulfate in annual layers of ice. You can find the study (open access), published on 6 June 2013 in IOP Publishing's journal Environmental Research Letters, at http://iopscience.iop.org/1748-9326/8/2/024035/article. Find out more about how volcanoes can influence climate.
  • EF-5 Tornado in El Reno, Oklahoma Widest Ever Recorded in US
    The EF-5 tornado that hit El Reno, Oklahoma on May 31st was the widest ever recorded in the US, acco...Read more

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    EF-5 Tornado in El Reno, Oklahoma Widest Ever Recorded in US

    The EF-5 tornado that hit El Reno, Oklahoma on May 31st was the widest ever recorded in the US, according to the National Weather Service in Norman Oklahoma. The tornado, which remained on the ground for 40 minutes and reached 2.6 miles across (4.2 km), took the lives of 18 people including storm chasers Tim Samaras, Paul Samaras and Carl Young. For more information on the tornado, visit http://ow.ly/i/2hfDG.
  • Atmospheric CO2 Level Tops 400 ppm
    During the week of May 13th, the CO2 level at the Mauna Loa Observatory in Hawaii topped 400 ppm rep...Read more

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    Atmospheric CO2 Level Tops 400 ppm

    During the week of May 13th, the CO2 level at the Mauna Loa Observatory in Hawaii topped 400 ppm repeatedly. Daily levels of CO2 can vary due to weather, and there are seasonal trends as well. The level of atmospheric greenhouse gases continues to increase, now over 120 ppm since the Industrial Revolution began. For more on the Keeling Curve, see http://keelingcurve.ucsd.edu/. Find out more about greenhouse gases and warming.

Evidence of Evolution

This illustration of the three domains of life is like a family tree. The branches that are very far apart are not very similar. Branches that are near each other indicate closely related groups.
Click on image for full size
Windows to the Universe original image

Evolution Hits the Beach

How Many Species Have There Been on Earth?

The Mystery of Mass Extinction is No Longer Murky

Early Whales Gave Birth on Land

What Is Evolution?

Evolution is the process of change through time. Many things evolve. Language evolves so that English spoken four hundred years ago during the time of playwright Shakespeare was very different than English spoken today. Technology evolves over time as new things are invented and modified. Scientific theories evolve as more data are collected and analyses are done. Life evolves over very long timescales as species change over many, many generations. This is called biological evolution. Evolution is the foundation for the modern sciences of paleontology (the study of fossils and the history of life), ecology (the study of ecosystems), and biology (the study of life) including medical science.

  • On a small scale, biological evolution is called microevolution and involves changes in the occurance of gene types in a population of the same species over several generations. These changes can lead to changes in the way a species looks over generations.
  • On a large scale, biological evolution is called macroevolution and involves the development of new species through cumulative genetic changes over many, many generations.

This Windows to the Universe Exploratour examines the scientific evidence for biological evolution. Click the “forward” button at the top of this page to continue the tour and learn more about the scientific basis of evolution.

Last modified May 15, 2009 by Jennifer Bergman.

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Learn about Earth and space science, and have fun while doing it! The games section of our online store includes a climate change card game and the Traveling Nitrogen game!

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Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Evolution Impacts Environment, Study Finds

Ecosystems have an impact on how living things evolve. And evolution has an impact on ecosystems too. Scientists have discovered the evolution of small fish called guppies affects the streams in which...more

Finding the Four-Footed Ancestors of Whales

Scientists have known for a long time that whales, the largest marine mammals, have distant relatives that lived on land millions of years ago. A team of scientists has been searching for fossils to better...more

How Many Species Have There Been on the Earth?

Scientists are interesting in knowing how many species can fit on the Earth. The number of species is called diversity. If there are a lot of species, then diversity is high. If there are few species,...more

Scientists Find Signs of “Snowball Earth” Amidst Early Animal Evolution

Near the Earth’s equator is where you could find some of the warmest places on Earth. But it wasn’t always like that. It used to be cold at the equator, so cold that ice formed on land and in the ocean....more

ExploraTour - Looking at the World in a Different Light

Look at the bed below the body of the sleeping man. You can still see where he was lying down. The heat from his body warmed up the bed sheets which are now radiating infrared light toward your eyes....more

ExploraTour - Looking at the World in a Different Light

All warm objects (not just people) release infrared light. Warmer objects give off more infrared light. Very hot objects radiate other types of light as well. Click on the picture to see the infrared...more

ExploraTour - Looking at the World in a Different Light

What kinds of light can people see? Our eyes can see visible light. When it passes into our eyes different types of visible light create different sensations that we see as colors. ...more

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The Winter 2010 issue of The Earth Scientist includes a variety of educational resources, ranging from astronomy to glaciers. Check out the other publications and classroom materials in our online store.

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF