IN AFRICA thats where you'll find many fossils :D
Biodiversity generally refers to the variety and variability of life on Earth. According to the United Nations Environment Programme(UNEP), biodiversity typically measures variation at the genetic, species, and ecosystem level.[1] Terrestrial biodiversity tends to be greater near the equator,[2] which seems to be the result of the warm climateand high primary productivity.[3] Biodiversity is not distributed evenly on Earth, and is richest in the tropics. These tropical forest ecosystems cover less than 10 percent of earth's surface, and contain about 90 percent of the world's species.[4] Marine biodiversitytends to be highest along coasts in the Western Pacific, where sea surface temperature is highest, and in the mid-latitudinal band in all oceans. There are latitudinal gradients in species diversity.[5]Biodiversity generally tends to cluster in hotspots,[6] and has been increasing through time,[7][8] but will be likely to slow in the future.[9]
Rapid environmental changes typically cause mass extinctions.[10][11][12] More than 99.9 percent of all species that ever lived on Earth, amounting to over five billion species,[13] are estimated to be extinct.lstimates on the number of Earth's current species range from 10 million to 14 million,[f which about 1.2 million have been documented and over 86 percent have not yet been described] More recently, in May 2016, scientists reported that 1 trillion species are estimated to be on Earth currently with only one-thousandth of one percent described.[18]The total amount of related DNA base pairson Earth is estimated at 5.0 x 1037 and weighs 50 billion tonnes.[19] In comparison, the total mass of the biosphere has been estimated to be as much as 4 TtC (trillion tons of carbon).[20] In July 2016, scientists reported identifying a set of 355 genes from the Last Universal Common Ancestor (LUCA) of all organisms living on Earth.[21]
The age of the Earth is about 4.54 billion years.[22][23][24] The earliest undisputed evidence of life on Earth dates at least from 3.5 billion years ago,[25][26][27] during the Eoarchean Era after a geological crust started to solidify following the earlier molten HadeanEon. There are microbial mat fossils found in 3.48 billion-year-old sandstone discovered in Western Australia.[28][29][30] Other early physical evidence of a biogenic substance is graphite in 3.7 billion-year-old meta-sedimentary rocks discovered in Western Greenland.More recently, in 2015, "remains of biotic life" were found in 4.1 billion-year-old rocks in Western Australia.[32][33] According to one of the researchers, "If life arose relatively quickly on Earth .. then it could be common in the universe.
decreased and then increased after major waves of mass extinctions
Answer is.
Maintaining the genetic diversity is long term solution which help to maintain polar bear population.
Explanation:
Polar bear from Norwegian way bears are genetically unique. These bears are only who survive in the world. they have lack genetic diversity so it is possible to they stay healthy and somehow survive in worst condition.
The climate and condition of Norwegian is way better so it is necessary to relocate the other polar bear. The other important thing is to ensure about their food. Polar bear mainly eat seal but due to the melting of ice they are unable to get proper food.
Answer:
Pineal gland
Explanation:
The suprachiasmatic nucleus is the paired nucleus made of about 1000 neurons each in the hypothalamus. The suprachiasmatic nucleus is involved in maintaining the endogenous clock or the internal clock.
The suprachiasmatic nucleus controls the circadian rhythm by controlling the amount of melatonin. The melatonin is produced by the pineal gland from the serotonin and tryptophan precursors. The hypothalamus thus controls the amount of the melatonin by regulating the pineal gland.
Thus, Pineal gland is the correct answer.
