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Beginning of animal evolution. [54] [55] 720–630 Ma Possible global glaciation [56] [57] which increased the atmospheric oxygen and decreased carbon dioxide, and was either caused by land plant evolution [58] or resulted in it. [59] Opinion is divided on whether it increased or decreased biodiversity or the rate of evolution. [60] [61] [62 ...
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 evolution of animals with backbones is one of the greatest stories in natural history. To tell this story, David presents explosive new fossil evidence from China, a region he has long dreamt of exploring and the frontier of modern paleontological research. This episode goes through how the vertebrates evolved and came onto land.
Earliest development of bilateral symmetry, mesoderm, head (anterior cephalization) and various gut muscles (and thus peristalsis) and, in the Nephrozoa, nephridia (kidney precursors), coelom (or maybe pseudocoelom), distinct mouth and anus (evolution of through-gut), and possibly even nerve cords and blood vessels. [8]
A recapitulation theory of evolutionary development was proposed by Étienne Serres in 1824–26, echoing the 1808 ideas of Johann Friedrich Meckel. They argued that the embryos of 'higher' animals went through or recapitulated a series of stages, each of which resembled an animal lower down the great chain of being.
The theory of recapitulation, also called the biogenetic law or embryological parallelism—often expressed using Ernst Haeckel's phrase "ontogeny recapitulates phylogeny"—is a historical hypothesis that the development of the embryo of an animal, from fertilization to gestation or hatching (), goes through stages resembling or representing successive adult stages in the evolution of the ...
Endless Forms Most Beautiful: The New Science of Evo Devo and the Making of the Animal Kingdom is a 2005 book by the molecular biologist Sean B. Carroll.It presents a summary of the emerging field of evolutionary developmental biology and the role of toolkit genes.
After Man: A Zoology of the Future is a 1981 speculative evolution book written by Scottish geologist and paleontologist Dougal Dixon and illustrated by several illustrators including Diz Wallis, John Butler, Brian McIntyre, Philip Hood, Roy Woodard and Gary Marsh.