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Natural selection is tantamount to common descent in that long-term occurrence and selection pressures can lead to the diversity of life on earth as found today. All adaptations—documented and undocumented changes concerned—are caused by natural selection (and a few other minor processes).
Most biologists agree however that the period since human emergence is part of a new mass extinction, named the Holocene extinction event, caused primarily by the impact humans are having on the environment. [124] It has been argued that the present rate of extinction is sufficient to eliminate most species on the planet Earth within 100 years ...
Evolution is the change in the heritable characteristics of biological populations over successive generations. [1] [2] It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. [3]
A species range map represents the region where individuals of a species can be found. This is a range map of Juniperus communis, the common juniper.. Species distribution, or species dispersion, [1] is the manner in which a biological taxon is spatially arranged. [2]
The most recent common ancestor of all currently living organisms is the last universal ancestor, [3] which lived about 3.9 billion years ago. [ 5 ] [ 6 ] The two earliest pieces of evidence for life on Earth are graphite found to be biogenic in 3.7 billion-year-old metasedimentary rocks discovered in western Greenland [ 7 ] and microbial mat ...
More than 99 percent of all species, amounting to over five billion species, [7] that ever lived on Earth are estimated to be extinct. [8] [9] Estimates on the number of Earth's current species range from 10 million to 14 million, [10] of which about 1.2 million have been documented and over 86 percent have not yet been described. [11]
Aurora Australis, or the Southern Lights, is a natural light display caused by solar wind particles colliding with Earth’s magnetic field. This creates colorful lights in the sky, typically ...
Natural selection acts on adaptive genes which allows the organisms to evolve. [7] The rate of evolution on adaptive genes is greater than on neutral genes due to the influence of selection. [8] However, it has been difficult to identify alleles for adaptive genes and thus adaptive genetic diversity is most often measured indirectly. [7]