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Gamma prime (γ'): This phase constitutes the precipitate used to strengthen the alloy. It is an intermetallic phase based on Ni 3 (Ti,Al) which have an ordered FCC L1 2 structure. [ 10 ] The γ' phase is coherent with the matrix of the superalloy having a lattice parameter that varies by around 0.5%.
Phylogeny: Found in a number of mammalian species, suggesting initial evolution tens of millions of years ago. Mechanism: Little is known about the neuromechanism. Ontogeny: Results from familiarity with another individual early in life, especially in the first 30 months for humans.
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 ...
Evolution is the change in a heritable trait in a population across generations since mutations generate variations in the heritable traits; they are considered the raw material for evolution. Therefore, beneficial mutation accumulations during the developmental processes could generate more phenotypic variations, which increases their gene ...
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 ...
The key stages that he discerned in early adulthood and midlife were as follows: Early Adult Transition (Ages 16–24) Forming a Life Structure (Ages 24–28) Settling down (Ages 29–34) Becoming One's Own Man (Ages 35–40) Midlife Transition (The early forties) Restabilization, into Late Adulthood (Age 45 and on) [37]
Evolutionary progress as a tree of life. Ernst Haeckel, 1866 Lamarck's two-factor theory involves 1) a complexifying force that drives animal body plans towards higher levels (orthogenesis) creating a ladder of phyla, and 2) an adaptive force that causes animals with a given body plan to adapt to circumstances (use and disuse, inheritance of acquired characteristics), creating a diversity of ...
Early mammals and possibly their eucynodontian ancestors had epipubic bones, which serve to hold the pouch in modern marsupials (in both sexes). 170-120 Ma Juramaia sinensis. Evolution of live birth , with early therians probably having pouches for keeping their undeveloped young like in modern marsupials.