Can we say how life on earth started?<\/p>\n
The origins of life on earth must predate the earliest fossils, and presumably must be simpler in form than even those earliest fossils. It is very unlikely that we will ever know what these life forms were,...<\/p>","DOI":"10.1093\/wentk\/9780190922894.003.0004","type":"book-chapter","created":{"date-parts":[[2020,11,12]],"date-time":"2020-11-12T18:34:23Z","timestamp":1605206063000},"source":"Crossref","is-referenced-by-count":0,"title":["Evolution of Life"],"prefix":"10.1093","author":[{"given":"Robin","family":"Dunbar","sequence":"first","affiliation":[]}],"member":"286","published-online":{"date-parts":[[2020,11,12]]},"container-title":["Evolution"],"original-title":["Evolution of Life"],"language":"en","deposited":{"date-parts":[[2022,7,6]],"date-time":"2022-07-06T00:46:45Z","timestamp":1657068405000},"score":9.849669,"resource":{"primary":{"URL":"https:\/\/whateveryoneneedstoknow.com\/view\/10.1093\/wentk\/9780190922894.001.0001\/isbn-9780190922894-book-part-4"}},"issued":{"date-parts":[[2020,11,12]]},"ISBN":["9780190922894","9780197569740"],"references-count":0,"URL":"https:\/\/doi.org\/10.1093\/wentk\/9780190922894.003.0004","published":{"date-parts":[[2020,11,12]]}},{"indexed":{"date-parts":[[2024,5,9]],"date-time":"2024-05-09T17:42:02Z","timestamp":1715276522383},"reference-count":0,"publisher":"Oxford University Press","isbn-type":[{"value":"9780190922894","type":"print"},{"value":"9780197569740","type":"electronic"}],"content-domain":{"domain":[],"crossmark-restriction":false},"published-print":{"date-parts":[[2020,12,17]]},"abstract":"
Who were our earliest ancestors?<\/p>\n
Our lineage can be said to have started when the African great apes of the late Miocene gave rise to a new, more terrestrial group, the australopithecines, some six or seven million years ago. Two important things had happened at...<\/p>","DOI":"10.1093\/wentk\/9780190922894.003.0007","type":"book-chapter","created":{"date-parts":[[2020,11,12]],"date-time":"2020-11-12T18:51:17Z","timestamp":1605207077000},"source":"Crossref","is-referenced-by-count":0,"title":["Evolution of Humans"],"prefix":"10.1093","author":[{"given":"Robin","family":"Dunbar","sequence":"first","affiliation":[]}],"member":"286","published-online":{"date-parts":[[2020,11,12]]},"container-title":["Evolution"],"original-title":["Evolution of Humans"],"language":"en","deposited":{"date-parts":[[2022,7,5]],"date-time":"2022-07-05T20:54:21Z","timestamp":1657054461000},"score":9.845269,"resource":{"primary":{"URL":"https:\/\/whateveryoneneedstoknow.com\/view\/10.1093\/wentk\/9780190922894.001.0001\/isbn-9780190922894-book-part-7"}},"issued":{"date-parts":[[2020,11,12]]},"ISBN":["9780190922894","9780197569740"],"references-count":0,"URL":"https:\/\/doi.org\/10.1093\/wentk\/9780190922894.003.0007","published":{"date-parts":[[2020,11,12]]}},{"indexed":{"date-parts":[[2024,5,9]],"date-time":"2024-05-09T17:41:58Z","timestamp":1715276518976},"reference-count":0,"publisher":"Oxford University Press","isbn-type":[{"value":"9780190922894","type":"print"},{"value":"9780197569740","type":"electronic"}],"content-domain":{"domain":[],"crossmark-restriction":false},"published-print":{"date-parts":[[2020,12,17]]},"abstract":"
What is a species?<\/p>\n
Having some way of classifying the natural world is important. That is the starting point of all science. For biology, it is also important for undertaking the kinds of very sophisticated statistical analyses that involve comparisons across different species and genera\u2014the...<\/p>","DOI":"10.1093\/wentk\/9780190922894.003.0005","type":"book-chapter","created":{"date-parts":[[2020,11,12]],"date-time":"2020-11-12T18:33:13Z","timestamp":1605205993000},"source":"Crossref","is-referenced-by-count":0,"title":["Evolution of Species"],"prefix":"10.1093","author":[{"given":"Robin","family":"Dunbar","sequence":"first","affiliation":[]}],"member":"286","published-online":{"date-parts":[[2020,11,12]]},"container-title":["Evolution"],"original-title":["Evolution of Species"],"language":"en","deposited":{"date-parts":[[2022,7,5]],"date-time":"2022-07-05T21:41:08Z","timestamp":1657057268000},"score":9.844706,"resource":{"primary":{"URL":"https:\/\/whateveryoneneedstoknow.com\/view\/10.1093\/wentk\/9780190922894.001.0001\/isbn-9780190922894-book-part-5"}},"issued":{"date-parts":[[2020,11,12]]},"ISBN":["9780190922894","9780197569740"],"references-count":0,"URL":"https:\/\/doi.org\/10.1093\/wentk\/9780190922894.003.0005","published":{"date-parts":[[2020,11,12]]}},{"indexed":{"date-parts":[[2024,5,9]],"date-time":"2024-05-09T17:41:58Z","timestamp":1715276518529},"reference-count":0,"publisher":"Oxford University Press","isbn-type":[{"value":"9780190922894","type":"print"},{"value":"9780197569740","type":"electronic"}],"content-domain":{"domain":[],"crossmark-restriction":false},"published-print":{"date-parts":[[2020,12,17]]},"abstract":"
How do species adapt to their environments?<\/p>\n
Darwin argued that species became increasingly adapted to their environments as variants (or what we would now call genetic mutants) that exhibited a slightly better fit to their environment survived better and were able to reproduce more successfully....<\/p>","DOI":"10.1093\/wentk\/9780190922894.003.0002","type":"book-chapter","created":{"date-parts":[[2020,11,12]],"date-time":"2020-11-12T18:12:39Z","timestamp":1605204759000},"source":"Crossref","is-referenced-by-count":0,"title":["Evolution and Adaptation"],"prefix":"10.1093","author":[{"given":"Robin","family":"Dunbar","sequence":"first","affiliation":[]}],"member":"286","published-online":{"date-parts":[[2020,11,12]]},"container-title":["Evolution"],"original-title":["Evolution and Adaptation"],"language":"en","deposited":{"date-parts":[[2022,7,6]],"date-time":"2022-07-06T00:37:16Z","timestamp":1657067836000},"score":9.829368,"resource":{"primary":{"URL":"https:\/\/whateveryoneneedstoknow.com\/view\/10.1093\/wentk\/9780190922894.001.0001\/isbn-9780190922894-book-part-2"}},"issued":{"date-parts":[[2020,11,12]]},"ISBN":["9780190922894","9780197569740"],"references-count":0,"URL":"https:\/\/doi.org\/10.1093\/wentk\/9780190922894.003.0002","published":{"date-parts":[[2020,11,12]]}},{"indexed":{"date-parts":[[2024,5,9]],"date-time":"2024-05-09T17:42:04Z","timestamp":1715276524650},"reference-count":0,"publisher":"Oxford University Press","isbn-type":[{"value":"9780190922894","type":"print"},{"value":"9780197569740","type":"electronic"}],"content-domain":{"domain":[],"crossmark-restriction":false},"published-print":{"date-parts":[[2020,12,17]]},"abstract":"
Why do some animals live in groups?<\/p>\n
The ancestral mammals were small (we can tell that from their fossils) and almost certainly solitary (as suggested by reconstructing their likely behavior from the social arrangements of living species using statistical analyses that take species evolutionary...<\/p>","DOI":"10.1093\/wentk\/9780190922894.003.0009","type":"book-chapter","created":{"date-parts":[[2020,11,12]],"date-time":"2020-11-12T19:15:23Z","timestamp":1605208523000},"source":"Crossref","is-referenced-by-count":0,"title":["Evolution of Sociality"],"prefix":"10.1093","author":[{"given":"Robin","family":"Dunbar","sequence":"first","affiliation":[]}],"member":"286","published-online":{"date-parts":[[2020,11,12]]},"container-title":["Evolution"],"original-title":["Evolution of Sociality"],"language":"en","deposited":{"date-parts":[[2022,7,5]],"date-time":"2022-07-05T20:36:46Z","timestamp":1657053406000},"score":9.813263,"resource":{"primary":{"URL":"https:\/\/whateveryoneneedstoknow.com\/view\/10.1093\/wentk\/9780190922894.001.0001\/isbn-9780190922894-book-part-9"}},"issued":{"date-parts":[[2020,11,12]]},"ISBN":["9780190922894","9780197569740"],"references-count":0,"URL":"https:\/\/doi.org\/10.1093\/wentk\/9780190922894.003.0009","published":{"date-parts":[[2020,11,12]]}},{"indexed":{"date-parts":[[2024,5,9]],"date-time":"2024-05-09T17:41:57Z","timestamp":1715276517205},"reference-count":0,"publisher":"Oxford University Press","isbn-type":[{"value":"9780190922894","type":"print"},{"value":"9780197569740","type":"electronic"}],"content-domain":{"domain":[],"crossmark-restriction":false},"published-print":{"date-parts":[[2020,12,17]]},"abstract":"
Why was the discovery of genetics so important for our understanding of evolution?<\/p>\n
Despite the fact that Darwin\u2019s theory of evolution was widely acclaimed by his scientific contemporaries, it had a central weakness that left it open to criticism. Neither Darwin nor anyone else had...<\/p>","DOI":"10.1093\/wentk\/9780190922894.003.0003","type":"book-chapter","created":{"date-parts":[[2020,11,12]],"date-time":"2020-11-12T17:51:29Z","timestamp":1605203489000},"source":"Crossref","is-referenced-by-count":0,"title":["Evolution and Genetics"],"prefix":"10.1093","author":[{"given":"Robin","family":"Dunbar","sequence":"first","affiliation":[]}],"member":"286","published-online":{"date-parts":[[2020,11,12]]},"container-title":["Evolution"],"original-title":["Evolution and Genetics"],"language":"en","deposited":{"date-parts":[[2022,7,5]],"date-time":"2022-07-05T21:08:48Z","timestamp":1657055328000},"score":9.801508,"resource":{"primary":{"URL":"https:\/\/whateveryoneneedstoknow.com\/view\/10.1093\/wentk\/9780190922894.001.0001\/isbn-9780190922894-book-part-3"}},"issued":{"date-parts":[[2020,11,12]]},"ISBN":["9780190922894","9780197569740"],"references-count":0,"URL":"https:\/\/doi.org\/10.1093\/wentk\/9780190922894.003.0003","published":{"date-parts":[[2020,11,12]]}},{"indexed":{"date-parts":[[2024,5,9]],"date-time":"2024-05-09T17:42:03Z","timestamp":1715276523102},"reference-count":0,"publisher":"Oxford University Press","isbn-type":[{"value":"9780190922894","type":"print"},{"value":"9780197569740","type":"electronic"}],"content-domain":{"domain":[],"crossmark-restriction":false},"published-print":{"date-parts":[[2020,12,17]]},"abstract":"
Why do some species eat others?<\/p>\n
Life began as microscopic single-celled organisms making their own energy from sunlight and other chemical resources. At some point, some of these creatures found it less effort just to eat their neighbors and acquire the energy they had gone...<\/p>","DOI":"10.1093\/wentk\/9780190922894.003.0006","type":"book-chapter","created":{"date-parts":[[2020,11,12]],"date-time":"2020-11-12T19:08:50Z","timestamp":1605208130000},"source":"Crossref","is-referenced-by-count":0,"title":["Evolution of Complexity"],"prefix":"10.1093","author":[{"given":"Robin","family":"Dunbar","sequence":"first","affiliation":[]}],"member":"286","published-online":{"date-parts":[[2020,11,12]]},"container-title":["Evolution"],"original-title":["Evolution of Complexity"],"language":"en","deposited":{"date-parts":[[2022,7,5]],"date-time":"2022-07-05T15:47:20Z","timestamp":1657036040000},"score":9.801508,"resource":{"primary":{"URL":"https:\/\/whateveryoneneedstoknow.com\/view\/10.1093\/wentk\/9780190922894.001.0001\/isbn-9780190922894-book-part-6"}},"issued":{"date-parts":[[2020,11,12]]},"ISBN":["9780190922894","9780197569740"],"references-count":0,"URL":"https:\/\/doi.org\/10.1093\/wentk\/9780190922894.003.0006","published":{"date-parts":[[2020,11,12]]}},{"indexed":{"date-parts":[[2024,5,9]],"date-time":"2024-05-09T17:42:06Z","timestamp":1715276526667},"reference-count":0,"publisher":"Oxford University Press","isbn-type":[{"value":"9780190922894","type":"print"},{"value":"9780197569740","type":"electronic"}],"content-domain":{"domain":[],"crossmark-restriction":false},"published-print":{"date-parts":[[2020,12,17]]},"abstract":"
What role does behavior play in evolution?<\/p>\n
Most adaptations ultimately require some level of genetic change, but genetic change depends in part on the availability of sufficient genetic variation within the population\u2014or, at the very least, the chance to produce new mutations. If the environmental...<\/p>","DOI":"10.1093\/wentk\/9780190922894.003.0008","type":"book-chapter","created":{"date-parts":[[2020,11,12]],"date-time":"2020-11-12T19:20:55Z","timestamp":1605208855000},"source":"Crossref","is-referenced-by-count":0,"title":["Evolution of Behavior"],"prefix":"10.1093","author":[{"given":"Robin","family":"Dunbar","sequence":"first","affiliation":[]}],"member":"286","published-online":{"date-parts":[[2020,11,12]]},"container-title":["Evolution"],"original-title":["Evolution of Behavior"],"language":"en","deposited":{"date-parts":[[2022,7,5]],"date-time":"2022-07-05T18:40:18Z","timestamp":1657046418000},"score":9.760857,"resource":{"primary":{"URL":"https:\/\/whateveryoneneedstoknow.com\/view\/10.1093\/wentk\/9780190922894.001.0001\/isbn-9780190922894-book-part-8"}},"issued":{"date-parts":[[2020,11,12]]},"ISBN":["9780190922894","9780197569740"],"references-count":0,"URL":"https:\/\/doi.org\/10.1093\/wentk\/9780190922894.003.0008","published":{"date-parts":[[2020,11,12]]}},{"indexed":{"date-parts":[[2026,1,27]],"date-time":"2026-01-27T23:11:42Z","timestamp":1769555502171,"version":"3.49.0"},"reference-count":0,"publisher":"Oxford University Press","isbn-type":[{"value":"9780190922894","type":"print"},{"value":"9780197569740","type":"electronic"}],"content-domain":{"domain":[],"crossmark-restriction":false},"published-print":{"date-parts":[[2020,12,17]]},"abstract":"
Does culture evolve?<\/p>\n
Culture is defined as those aspects of our behavior and beliefs that are learned\u2014passed on from parents to children or between two unrelated individuals, by copying and instruction. Given that evolution simply means the way traits change over time, and all cultural...<\/p>","DOI":"10.1093\/wentk\/9780190922894.003.0010","type":"book-chapter","created":{"date-parts":[[2020,11,12]],"date-time":"2020-11-12T18:39:57Z","timestamp":1605206397000},"source":"Crossref","is-referenced-by-count":1,"title":["Evolution of Culture"],"prefix":"10.1093","author":[{"given":"Robin","family":"Dunbar","sequence":"first","affiliation":[]}],"member":"286","published-online":{"date-parts":[[2020,11,12]]},"container-title":["Evolution"],"original-title":["Evolution of Culture"],"language":"en","deposited":{"date-parts":[[2022,7,5]],"date-time":"2022-07-05T23:04:41Z","timestamp":1657062281000},"score":9.760857,"resource":{"primary":{"URL":"https:\/\/whateveryoneneedstoknow.com\/view\/10.1093\/wentk\/9780190922894.001.0001\/isbn-9780190922894-book-part-10"}},"issued":{"date-parts":[[2020,11,12]]},"ISBN":["9780190922894","9780197569740"],"references-count":0,"URL":"https:\/\/doi.org\/10.1093\/wentk\/9780190922894.003.0010","published":{"date-parts":[[2020,11,12]]}},{"indexed":{"date-parts":[[2024,5,15]],"date-time":"2024-05-15T05:40:51Z","timestamp":1715751651689},"reference-count":0,"publisher":"Oxford University Press","isbn-type":[{"value":"9780197619629","type":"print"},{"value":"9780197764824","type":"electronic"}],"content-domain":{"domain":[],"crossmark-restriction":false},"published-print":{"date-parts":[[2022,11,23]]},"abstract":"
Human activities are having enormous effects on nature, including extinction of many species. This leatherback turtle ( Why do we need a theory of evolution?<\/p>\n We live in a world of immense diversity. There are around 5,500 species of mammals and some 10,000 species of birds. But even that pales into insignificance beside the 12,000 species of roundworms, about half of whom...<\/p>","DOI":"10.1093\/wentk\/9780190922894.003.0001","type":"book-chapter","created":{"date-parts":[[2020,11,12]],"date-time":"2020-11-12T19:48:39Z","timestamp":1605210519000},"source":"Crossref","is-referenced-by-count":0,"title":["Evolution and Natural Selection"],"prefix":"10.1093","author":[{"given":"Robin","family":"Dunbar","sequence":"first","affiliation":[]}],"member":"286","published-online":{"date-parts":[[2020,11,12]]},"container-title":["Evolution"],"original-title":["Evolution and Natural Selection"],"language":"en","deposited":{"date-parts":[[2022,7,5]],"date-time":"2022-07-05T17:27:20Z","timestamp":1657042040000},"score":9.679308,"resource":{"primary":{"URL":"https:\/\/whateveryoneneedstoknow.com\/view\/10.1093\/wentk\/9780190922894.001.0001\/isbn-9780190922894-book-part-1"}},"issued":{"date-parts":[[2020,11,12]]},"ISBN":["9780190922894","9780197569740"],"references-count":0,"URL":"https:\/\/doi.org\/10.1093\/wentk\/9780190922894.003.0001","published":{"date-parts":[[2020,11,12]]}},{"indexed":{"date-parts":[[2024,5,15]],"date-time":"2024-05-15T05:40:45Z","timestamp":1715751645901},"reference-count":0,"publisher":"Oxford University Press","isbn-type":[{"value":"9780197619629","type":"print"},{"value":"9780197764824","type":"electronic"}],"content-domain":{"domain":[],"crossmark-restriction":false},"published-print":{"date-parts":[[2022,11,23]]},"abstract":" A giant barrel sponge ( How did the precisely arranged pattern of stripes of this plains zebra ( This chapter reviews experimental evolution. Many of the evolutionary processes extend over long periods of time\u2014long, that is, on human timescales of a few decades. With the resource of a laboratory, we can follow the evolution of large populations over thousands of generations in a few months. Such experiments can be used to probe evolutionary mechanisms in deep time. They have shifted evolutionary biology from a comparative science that interprets patterns of variation into an experimental science capable of documenting the smallest details of how evolution occurs. The chapter then outlines the two basic ways of setting up a microcosm: through batch culture or continuous culture. It also considers how deleterious mutation is balanced by purifying selection, and how beneficial mutation drives directional selection.<\/p>","DOI":"10.1093\/hesc\/9780198712572.003.0013","type":"book-chapter","created":{"date-parts":[[2023,9,15]],"date-time":"2023-09-15T07:47:12Z","timestamp":1694764032000},"source":"Crossref","is-referenced-by-count":0,"title":["Experimental Evolution"],"prefix":"10.1093","author":[{"given":"Graham","family":"Bell","sequence":"first","affiliation":[]}],"member":"286","published-online":{"date-parts":[[2023,8,31]]},"container-title":["The Evolution of Life"],"original-title":["Experimental Evolution"],"language":"en","link":[{"URL":"https:\/\/www.oxfordsciencetrove.com\/display\/10.1093\/hesc\/9780198712572.001.0001\/isbn-9780198712572-book-part-13","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,2,6]],"date-time":"2024-02-06T08:43:06Z","timestamp":1707208986000},"score":9.621587,"resource":{"primary":{"URL":"https:\/\/www.oxfordsciencetrove.com\/view\/10.1093\/hesc\/9780198712572.001.0001\/isbn-9780198712572-book-part-13"}},"issued":{"date-parts":[[2014,12,4]]},"ISBN":["9780198712572","9780191975141"],"references-count":0,"URL":"https:\/\/doi.org\/10.1093\/hesc\/9780198712572.003.0013","published":{"date-parts":[[2014,12,4]]}},{"indexed":{"date-parts":[[2024,5,15]],"date-time":"2024-05-15T03:33:25Z","timestamp":1715744005346},"reference-count":0,"publisher":"Oxford University Press","isbn-type":[{"value":"9780198862574","type":"print"},{"value":"9780191975615","type":"electronic"}],"content-domain":{"domain":[],"crossmark-restriction":false},"published-print":{"date-parts":[[2021,11,18]]},"abstract":" This chapter introduces the theory of evolution, which sparked concepts of competition, struggle, uncertainty, and random chance before it became the major unifying principle of biological sciences. The crucial concept of species is constantly referred to in discussions around this theory. Selection is the driver behind the evolution of species, while natural selection leads to the speciation and extinction of species. The chapter lists the different types of selection: stabilizing selection, sexual selection, disruptive selection, and directional selection. It also highlights the foundational works of Charles Darwin and Gregor Mendel establishing the field of evolution. The birth and death of species, through these works, came to be understood as central to the evolution of life on Earth.<\/p>","DOI":"10.1093\/hesc\/9780198862574.003.0001","type":"book-chapter","created":{"date-parts":[[2023,9,15]],"date-time":"2023-09-15T07:55:50Z","timestamp":1694764550000},"source":"Crossref","is-referenced-by-count":0,"title":["Introducing Evolution"],"prefix":"10.1093","author":[{"given":"Neil","family":"Ingram","sequence":"first","affiliation":[]},{"given":"Sylvia Hixson","family":"Andrews","sequence":"additional","affiliation":[]},{"given":"Jane","family":"Still","sequence":"additional","affiliation":[]}],"member":"286","published-online":{"date-parts":[[2021,11,18]]},"container-title":["Evolution"],"original-title":["Introducing Evolution"],"language":"en","link":[{"URL":"https:\/\/www.oxfordsciencetrove.com\/display\/10.1093\/hesc\/9780198862574.001.0001\/isbn-9780198862574-book-part-1","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,2,6]],"date-time":"2024-02-06T08:59:46Z","timestamp":1707209986000},"score":9.621411,"resource":{"primary":{"URL":"https:\/\/www.oxfordsciencetrove.com\/view\/10.1093\/hesc\/9780198862574.001.0001\/isbn-9780198862574-book-part-1"}},"issued":{"date-parts":[[2021,11,18]]},"ISBN":["9780198862574","9780191975615"],"references-count":0,"URL":"https:\/\/doi.org\/10.1093\/hesc\/9780198862574.003.0001","published":{"date-parts":[[2021,11,18]]}},{"indexed":{"date-parts":[[2026,1,18]],"date-time":"2026-01-18T04:09:24Z","timestamp":1768709364438,"version":"3.49.0"},"reference-count":0,"publisher":"Oxford University Press","isbn-type":[{"value":"9780195049121","type":"print"},{"value":"9780197560051","type":"electronic"}],"content-domain":{"domain":[],"crossmark-restriction":false},"published-print":{"date-parts":[[1988,11,24]]},"abstract":" In the preceding chapters we have built up the premises of an argument concerning morphogenesis and evolution. These are as follows: 1.Evolution occurs through processes of introduction and sorting of variation. 2.In a genealogical hierarchy, introduction and sorting of variation can occur at a series of focal levels and it is a property of the hierarchy that there is upward and downward causation between focal levels. 3.The crucial role of developmental processes with respect to evolutionary mechanisms is in the causation of new phenotypes. Phenotypes are always expressed in individual organisms, but the properties of other focal levels in the genealogical hierarchy must also be considered. 4.Development is also essentially hierarchical, involving processes acting at different focal levels. Each level is defined as the place where new gene expression occurs. For simplicity we can divide its hierarchy into stages from early pattern formation to late cytodifferentiation, each including unknown (but very large) numbers of phases of new gene expression. It must be noted that ontogeny of a given individual or given taxon represents a route through the basic hierarchy of developmental stages that, through historical accident or selective bias, may be extremely convoluted and unpredictable. 5.In the systematics of any group, there is a general correlation between taxonomic rank and different grades or ranks of morphological characters. There is a series of levels or grades of generality of phenotypic characters caused at different levels of the morphogenetic hierarchy. 6.The morphogenetic hierarchy that produces the different grades of phenotypic morphology can potentially involve upward but little if any downward causation. 7.The course of evolution appears principally to produce clusters of evolutionarily equivalent species rather than lines of progressive change. At any taxonomic level, diversification within a group has therefore to be distinguished from those rarer phases of progressive evolution leading to establishment of new groups. The two involve quite different processes because they involve the morphogenetic causation of different levels of morphological characters. 8.Phenotypic characters may occur in groups that are linked both in the sense of functional integration of the phenotype itself and\/or by virtue of the integration and interdependency of developmental pathways in morphogenesis.<\/p>","DOI":"10.1093\/oso\/9780195049121.003.0011","type":"book-chapter","created":{"date-parts":[[2020,11,10]],"date-time":"2020-11-10T23:14:46Z","timestamp":1605050086000},"source":"Crossref","is-referenced-by-count":8,"title":["Morphogenesis and Evolution"],"prefix":"10.1093","author":[{"given":"Keith Stewart","family":"Thomson","sequence":"first","affiliation":[]}],"member":"286","published-online":{"date-parts":[[2020,11,12]]},"container-title":["Morphogenesis and Evolution"],"original-title":["Morphogenesis and Evolution"],"language":"en","deposited":{"date-parts":[[2022,8,2]],"date-time":"2022-08-02T21:29:50Z","timestamp":1659475790000},"score":9.557538,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/book\/40845\/chapter\/348875464"}},"issued":{"date-parts":[[1988,11,24]]},"ISBN":["9780195049121","9780197560051"],"references-count":0,"URL":"https:\/\/doi.org\/10.1093\/oso\/9780195049121.003.0011","published":{"date-parts":[[1988,11,24]]}},{"indexed":{"date-parts":[[2024,9,15]],"date-time":"2024-09-15T21:06:39Z","timestamp":1726434399020},"reference-count":0,"publisher":"Oxford University Press","isbn-type":[{"type":"print","value":"9780195049121"},{"type":"electronic","value":"9780197560051"}],"content-domain":{"domain":[],"crossmark-restriction":false},"published-print":{"date-parts":[[1988,11,24]]},"abstract":" We now need to look more closely at the evolutionary patterns that we wish to explain. Again, we can use the study of patterns to discover and define important problems to be solved. The methods available for the study of patterns depend on the focal level of the mechanism with which one is concerned. If our interest is in individual variation, naturally we need extensive sampling and laboratory experimentation, looking at individuals within populations. In order to study the biology of populations we must work at the population level, and at such phenomena as gene and character frequencies in the field and laboratory. It is at this level that workers have most readily been able to measure selection coefficients and other quantitative elements of evolutionary science. If our interest is in the processes of speciation we must look as closely as possible at examples of the process in action\u2014at sibling species, at a whole range of hybridization patterns in the wild and laboratory, at the distribution of closely related species in space and time. (It will be noted that between population-level work and species-level work there is an unfortunate gap; one can look at prespeciation and postspeciation situations but it is rare indeed to be confident that one is looking at speciation in flagrante delicto.) We can also look beyond the species level at phenomena of species distribution within higher taxa. Here we progress to using the methods of systematic biology and comparative morphology and paleontology. Each of these different approaches gives a different view of the evolutionary process and, therefore, in terms of the questions discussed in this book, gives us a different view of the role of mechanisms acting at the developmental level within evolutionary mechanisms. Obviously the most immediate element of causality in the origin of adaptive structures resulting from developmental properties is in the matter of individual phenotypic variation, but some of the most interesting questions concern the consequences of developmental properties for higher focal levels\u2014their upwardly causing properties. To examine these we need to look at the species level and beyond (what has often been termed croevolution).<\/p>","DOI":"10.1093\/oso\/9780195049121.003.0010","type":"book-chapter","created":{"date-parts":[[2020,11,11]],"date-time":"2020-11-11T01:07:56Z","timestamp":1605056876000},"source":"Crossref","is-referenced-by-count":0,"title":["Patterns of Evolution"],"prefix":"10.1093","author":[{"given":"Keith Stewart","family":"Thomson","sequence":"first","affiliation":[]}],"member":"286","published-online":{"date-parts":[[2020,11,12]]},"container-title":["Morphogenesis and Evolution"],"original-title":["Patterns of Evolution"],"language":"en","deposited":{"date-parts":[[2022,8,2]],"date-time":"2022-08-02T21:29:50Z","timestamp":1659475790000},"score":9.534219,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/book\/40845\/chapter\/348875367"}},"issued":{"date-parts":[[1988,11,24]]},"ISBN":["9780195049121","9780197560051"],"references-count":0,"URL":"https:\/\/doi.org\/10.1093\/oso\/9780195049121.003.0010","published":{"date-parts":[[1988,11,24]]}},{"indexed":{"date-parts":[[2025,10,4]],"date-time":"2025-10-04T00:48:52Z","timestamp":1759538932281,"version":"build-2065373602"},"reference-count":0,"publisher":"Oxford University Press (OUP)","issue":"1","license":[{"start":{"date-parts":[[1981,1,1]],"date-time":"1981-01-01T00:00:00Z","timestamp":347155200000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1"},{"start":{"date-parts":[[2017,5,31]],"date-time":"2017-05-31T00:00:00Z","timestamp":1496188800000},"content-version":"vor","delay-in-days":13299,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Evolution"],"published-print":{"date-parts":[[1981,1]]},"DOI":"10.1111\/j.1558-5646.1981.tb04865.x","type":"journal-article","created":{"date-parts":[[2017,5,31]],"date-time":"2017-05-31T15:51:00Z","timestamp":1496245860000},"page":"138-138","source":"Crossref","is-referenced-by-count":1,"title":["EVOLUTION SOCIETY NEWS"],"prefix":"10.1093","volume":"35","member":"286","published-online":{"date-parts":[[2017,5,31]]},"container-title":["Evolution"],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1111%2Fj.1558-5646.1981.tb04865.x","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/onlinelibrary.wiley.com\/wol1\/doi\/10.1111\/j.1558-5646.1981.tb04865.x\/fullpdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,3]],"date-time":"2025-10-03T20:40:09Z","timestamp":1759524009000},"score":9.5137,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/evolut\/article\/35\/1\/138\/6871628"}},"issued":{"date-parts":[[1981,1]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1981,1]]}},"URL":"https:\/\/doi.org\/10.1111\/j.1558-5646.1981.tb04865.x","archive":["Portico"],"ISSN":["0014-3820"],"issn-type":[{"type":"print","value":"0014-3820"}],"published":{"date-parts":[[1981,1]]}},{"indexed":{"date-parts":[[2024,5,12]],"date-time":"2024-05-12T06:00:03Z","timestamp":1715493603099},"reference-count":0,"publisher":"Oxford University Press","isbn-type":[{"value":"9780195122343","type":"print"},{"value":"9780197561300","type":"electronic"}],"content-domain":{"domain":[],"crossmark-restriction":false},"published-print":{"date-parts":[[2003,3,13]]},"abstract":" Adaptive evolution\u2014phenotypic improvement due to selection\u2014is the central theme of Darwinian evolutionary biology. The concept of adaptive evolution by selection on heritable variation underlies every evolutionary analysis of form, function, and fitness. How biologists view adaptive evolution\u2014 how they are taught to view it\u2014has a profound influence on thinking and research in virtually every area of biology. Despite the importance of adaptive evolution, there is still controversy over how to relate development and selection in discussions of adaptive design (e.g. see Charlesworth, 1990; Amundson, 1996). It is a controversy that began in the late nineteenth century, when biologists unfortunately began to dichotomize development and selection, as if they were opposing factors in evolution (see the discussion of gradualism in chapter 24). The modern version of this debate dichotomizes selection and developmental constraints (e.g., see Maynard Smith et al., 1985; Bell, 1989; Ridley, 1993; Amundson, 1996; see also chapter 1). Phylogenetic constraint is another version of developmental constraint, since it refers to limits imposed by ancestry (inherited developmental patterns) on current form as does the idea of developmental constraint. The dichotomy between selection and development, as if they were opposed factors in adaptive evolution, is misconceived. Adaptive evolution is a two-step process: first the generation of variation by development, then the screening of that variation by selection (Mayr, 1962; Endler and McLellan, 1988, p. 395). If an established trait (one widespread in a population) persists through phylogenetic branching events, this is not evidence against selection as an explanation for the trait (cf. Coddington, 1988), as if speciation reduces the importance of selection. Rather, it could be taken as evidence that selection is important for maintenance of the trait in more than one lineage: trait persistence over long time spans certainly does not represent absence of continued selection, since it is known that traits no longer favored by selection, such as the eyes of cave animals and walking limbs in whales, are often lost (for other classic examples, see Rensch, 1960).<\/p>","DOI":"10.1093\/oso\/9780195122343.003.0011","type":"book-chapter","created":{"date-parts":[[2020,11,11]],"date-time":"2020-11-11T00:55:48Z","timestamp":1605056148000},"source":"Crossref","is-referenced-by-count":0,"title":["Adaptive Evolution"],"prefix":"10.1093","author":[{"given":"Mary Jane","family":"West-Eberhard","sequence":"first","affiliation":[]}],"member":"286","published-online":{"date-parts":[[2020,11,12]]},"container-title":["Developmental Plasticity and Evolution"],"original-title":["Adaptive Evolution"],"language":"en","deposited":{"date-parts":[[2022,8,2]],"date-time":"2022-08-02T21:08:29Z","timestamp":1659474509000},"score":9.49083,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/book\/40908\/chapter\/349014417"}},"issued":{"date-parts":[[2003,3,13]]},"ISBN":["9780195122343","9780197561300"],"references-count":0,"URL":"https:\/\/doi.org\/10.1093\/oso\/9780195122343.003.0011","published":{"date-parts":[[2003,3,13]]}},{"indexed":{"date-parts":[[2024,5,15]],"date-time":"2024-05-15T05:40:50Z","timestamp":1715751650833},"reference-count":0,"publisher":"Oxford University Press","isbn-type":[{"value":"9780197619629","type":"print"},{"value":"9780197764824","type":"electronic"}],"content-domain":{"domain":[],"crossmark-restriction":false},"published-print":{"date-parts":[[2022,11,23]]},"abstract":" Several species of grasses have been modified by human selection to make them the major food in many parts of the world. Among them is rice (