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Evolution - Coggle Diagram
Evolution
History of Life
lifes record history: hadean, archaean, proterozoic, phanerozoic eons
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early atmosphere: little oxygen and contained water vapour and chemicals released by volcanic eruptions
conditions on early earth made life possible: abiotic synthesis of small organic molecules - joining of the small molecules into macromolecules - packaging of molecules into protocells - origin of self-replicating molecules
miller and urey: demonstrated that the abiotic synthesis of organic molecules in a reducing atmosphere was possible - other experiments found that many AA formed under conditions simulating volcanic eruption // organic compounds may have formed in reducing conditions near openings of volcanos
organic compounds may have also been formed in deep sea hydrothermal vents (areas on the sea floor where hot water and minerals gush from earth's interior into ocean)
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endosymbiosis = symbiotic incorportaion of one organism by another - eukaryotes created by endosymbiosis - prokaryotic cell engulfed another that would evolve into a mitochondrion and plastids
serial endosymbiosis: supposes that mitochondria evolved before plastids via sequence of endosymbiotic evenets
evidence supporting: inner membranes of both mitochondria and plastids are similiar to plasma membrane structure of living bacteria / dna structure and cell division are similiar to bacterai / both organelles transcribe and translate their own dna / ribosomes are more similiar to bacterial than to aukaryotic ribosome
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the cambrian - loads of diverse species w/ complex bodies, heads, mouths, guts , legs <- evidence for first predator-prey interactions - had claws and other adaptations - new defense adaptations eg sharp spines and body armour
the cambrian explosion = sudden appearence of fossils resembling modern animal phyla in the cambrian period - sponges were around earlier
colonization of land; fungi, plants and aniamls colonized 500 mya - many plants evolved to reproduce on land and avoid dehydration
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fossilised plants show evidence of mutually beneficial associations w/fungi as they colonized land together
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fossils, global change and macroevolution
fossils = remains of the past, found in sedimentary rock in layers called strata - Cuvier speculated that boundaries between strate represented catastrophic ecents
fossil record is biased in favour of a species that existed for a long time, were abundant and widespread, had hard parts eg shells
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origin of mammels - mammels belong to tetrapod group - mamalian deatures can be traced in fossils eg jaw and teeth evolution - darwin called this 'descent with modification'
tinkering: exaptations are structures that evolve in one contect but become co-opted for a diff function - structures dont evolve in anticipation for future use
phanerozoic = period when complex life forms were evovling post cabrian explosion - expect shifts in biomes due to climate chnage
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adaptive radiations = rapid evolution of diversely adapted species from a common ancestro - adaptive radiations may follwo such as mass exticntions, evolution of novel characteristics, colonization of new regions
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