accumulate and ultimately produce new traits in organisms.
In a completely different realm of science, in the world of paleontology, fossil evidence shows that life has existed for most of Earth’ s history. Across the globe, in Western Australia, paleontologists have discovered that stromatolites, or layered rocks resulting from bacterial activity, and cyanobacteria fossils, have been determined to be 3.5 million years and 3.4 million years old, respectively. Other chemical tests suggest that life existed even before then.
older materials overall did not resemble the more current organisms as closely as the younger materials. This suggested to many scientists that the over time, the organisms changed.
Modern stromatolites are formed from cyanobacteria and trapped sediments. The buildup of these layers are found in Precambrian rocks and are some of the earliest known fossils.
Further evidence of evolution in the world of paleontology correlates with the methods used to date certain fossils- examining the age of rocks. In the early nineteenth century, scientists realized that fossils appear in layers of sedimentary rock, or rocks formed by the particles deposited by water, wind or ice. They noticed that the older material was deposited deeper in and toward the bottom of the sedimentary rock, whereas the more recent materials were deposited in layers above the older materials. The fossils in the
Next, evidence in the branch of biogeography, which deals with the geographic distribution of organisms, further supports evolution: take
31 VOGUE JUNE 2013