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"Axis of Upheaval" is a term coined in 2024 by Center for a New American Security foreign policy analysts Richard Fontaine and Andrea Kendall-Taylor and used by many foreign policy analysts, [1] [2] [3] military officials, [4] [5] and international groups [6] to describe the growing anti-Western collaboration between Russia, Iran, China and ...
Photoperiod is the change of day length around the seasons. The rotation of the earth around its axis produces 24 hour changes in light (day) and dark (night) cycles on earth. The length of the light and dark in each phase varies across the seasons due to the tilt of the earth around its axis.
The geographic poles are defined by the points on the surface of Earth that are intersected by the axis of rotation. The pole shift hypothesis describes a change in location of these poles with respect to the underlying surface – a phenomenon distinct from the changes in axial orientation with respect to the plane of the ecliptic that are caused by precession and nutation, and is an ...
Sea level above present day 180 m; rising to 220 m in Caradoc and falling sharply to 140 m in end-Ordovician glaciations [ 8 ] The Ordovician ( / ɔːr d ə ˈ v ɪ ʃ i . ə n , - d oʊ -, - ˈ v ɪ ʃ ən / or-də- VISH -ee-ən, -doh-, - VISH -ən ) [ 9 ] is a geologic period and system , the second of six periods of the Paleozoic Era ...
Timelines are often used in education [14] to help students and researchers with understanding the order or chronology of historical events and trends for a subject. To show time on a specific scale on an axis, a timeline can visualize time lapses between events, durations (such as lifetimes or wars), and the simultaneity or the overlap of ...
Symmetry breaking in biology is the process by which uniformity is broken, or the number of points to view invariance are reduced, to generate a more structured and improbable state. [1] Symmetry breaking is the event where symmetry along a particular axis is lost to establish a polarity.
In biology, evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organization , from kingdoms to species , and individual organisms and molecules , such as DNA and proteins .
The idea of a tree of life arose from ancient notions of a ladder-like progression from lower into higher forms of life (such as in the Great Chain of Being).Early representations of "branching" phylogenetic trees include a "paleontological chart" showing the geological relationships among plants and animals in the book Elementary Geology, by Edward Hitchcock (first edition: 1840).