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Matthias Jakob Schleiden (German: [maˈtiːas ˈjaːkɔp ˈʃlaɪdn̩]; [1] [2] 5 April 1804 – 23 June 1881) was a German botanist and co-founder of cell theory, along with Theodor Schwann and Rudolf Virchow.
The book has been called "a conspicuous milestone in nineteenth century biology" by Karl Sudhoff and "epoch making" By Francis Münzer. [3] The book, originally published in German, was translated to English in 1847 by Henry Spencer Smith in an edition that also contained the treatise Phytogenesis, by Matthias Schleiden. [4]
In the 1960s, it was determined that the Earth's earliest life-forms treated as plants, the cyanobacteria known as stromatolites, dated back some 3.5 billion years. [118] Mid-century transmission and scanning electron microscopy presented another level of resolution to the structure of matter, taking anatomy into the new world of "ultrastructure".
The earliest evidence for life on Earth includes: 3.8 billion-year-old biogenic hematite in a banded iron formation of the Nuvvuagittuq Greenstone Belt in Canada; [30] graphite in 3.7 billion-year-old metasedimentary rocks in western Greenland; [31] and microbial mat fossils in 3.48 billion-year-old sandstone in Western Australia.
The history of life on Earth traces the processes by which living and extinct organisms evolved, from the earliest emergence of life to the present day. Earth formed about 4.5 billion years ago (abbreviated as Ga, for gigaannum) and evidence suggests that life emerged prior to 3.7 Ga. [1] [2] [3] The similarities among all known present-day species indicate that they have diverged through the ...
The age of Earth is about 4.54 billion years; [7] [33] [34] the earliest undisputed evidence of life on Earth dates from at least 3.5 billion years ago according to the stromatolite record. [35] Some computer models suggest life began as early as 4.5 billion years ago. [36] [37] The oldest evidence of life is indirect in the form of isotopic ...
The identification of plant fossils in Cambrian strata is an uncertain area in the evolutionary history of plants because of the small and soft-bodied nature of these plants. It is also difficult in a fossil of this age to distinguish among various similar appearing groups with simple branching patterns, and not all of these groups are plants.
The Purple Earth Hypothesis (PEH) is an astrobiological hypothesis, first proposed by molecular biologist Shiladitya DasSarma in 2007, [1] that the earliest photosynthetic life forms of Early Earth were based on the simpler molecule retinal rather than the more complex porphyrin-based chlorophyll, making the surface biosphere appear purplish ...