What does the Cambrian explosion tell us about evolution?
The Cambrian explosion happened more than 500 million years ago. It was when most of the major animal groups started to appear in the fossil record, a time of rapid expansion of different forms of life on Earth.
What evidence do we have for the Cambrian explosion?
Morphology and phylogenetics revealed by fossils. Perhaps the strongest evidence to support the Cambrian evolutionary explosion of animal forms is the first clear appearance, in the Early Cambrian, of skeletal fossils representing members of many marine bilaterian animal phyla.
What is the Cambrian explosion and why is it significant?
The Cambrian Period marks an important point in the history of life on Earth; it is the time when most of the major groups of animals first appear in the fossil record. This event is sometimes called the “Cambrian Explosion,” because of the relatively short time over which this diversity of forms appears.
What 3 factors could account for the Cambrian explosion?
8.1.1 Increase in oxygen levels.
How did the Cambrian explosion impact life on Earth?
The Cambrian period, part of the Paleozoic era, produced the most intense burst of evolution ever known. The Cambrian Explosion saw an incredible diversity of life emerge, including many major animal groups alive today. Among them were the chordates, to which vertebrates (animals with backbones) such as humans belong.
What caused the Cambrian explosion of life?
Oxygen fluctuations stalled life on Earth Given the importance of oxygen for animals, researchers suspected that a sudden increase in the gas to near-modern levels in the ocean could have spurred the Cambrian explosion.
What was Earth like during the Paleozoic Era?
During the late Paleozoic, huge, swampy forest regions covered much of the northern continents. Plant and animal life flourished. Amphibians left the oceans to live on land, reptiles evolved as fully terrestrial life-forms, and insect life began. Ferns grew to tree size, and precursors of the conifers appeared.
Why was the Cambrian explosion such a unique event?
What era are we currently in?
Cenozoic era
Currently, we’re in the Phanerozoic eon, Cenozoic era, Quaternary period, Holocene epoch and (as mentioned) the Meghalayan age.
What important evolutionary step occurred in the Proterozoic?
Free oxygen in the atmosphere increased significantly as a result of biological activity during the Proterozoic. The most important period of change occurred between 2.3 billion and 1.8 billion years ago when free oxygen began to accumulate in the atmosphere.