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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 ...
Arnold I. Miller (2002). "Diversity of Life Through Time". Encyclopedia of Life Sciences. John Wiley & Sons. John Phillips (1841). Figures and descriptions of Palaeozoic fossils of Cornwall, Devon and West Somerset, Observed in the Course of the Ordnance Survey of that District. London: Longman. The Succession of Life in the Sea
Figure 1:In mammals, the quadrate and articular bones are small and part of the middle ear; the lower jaw consists only of dentary bone.. While living mammal species can be identified by the presence of milk-producing mammary glands in the females, other features are required when classifying fossils, because mammary glands and other soft-tissue features are not visible in fossils.
c. 560 Ma – Trace fossils, e.g., worm burrows, and small bilaterally symmetrical animals. Earliest arthropods. Earliest fungi. c. 558 Ma – Dickinsonia, a large slow moving disc-like creature, first appears – the discovery of fat molecules in its tissues make it the first confirmed true metazoan animal of the fossil record.
The tree of life or universal tree of life is a metaphor, conceptual model, and research tool used to explore the evolution of life and describe the relationships between organisms, both living and extinct, as described in a famous passage in Charles Darwin's On the Origin of Species (1859). [1]
Variations in the toolkit may have produced a large part of the morphological evolution of animals. The toolkit can drive evolution in two ways. A toolkit gene can be expressed in a different pattern, as when the beak of Darwin's large ground-finch was enlarged by the BMP gene, [62] or when snakes lost their legs as distal-less became under ...
Evolution of fish – Origin and diversification of fish through geologic time; Evolution of insects – Development of insects from an ancestral crustacean and their subsequent radiation Evolution of butterflies – Origin and diversification of butterflies through geologic time; Peppered moth evolution – Significance of the peppered moth in ...