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Allochronic speciation (also known as allochronic isolation, or temporal isolation) is a form of speciation (specifically ecological speciation) arising from reproductive isolation that occurs due to a change in breeding time that reduces or eliminates gene flow between two populations of a species.
[1]: 229 However, a biozone may vary in age from one location or another. For example, a given taxon may migrate, so its first appearance varies from place to place. In particular, facies-controlled organisms (organisms that lived in a particular sedimentary environment ) are not well suited for biochronology because they move with their ...
In palaeontology, the evidence for species and evolution comes mainly from the comparative anatomy of fossils. A chronospecies is defined in a single lineage (solid line) whose morphology changes with time. At some point, palaeontologists judge that enough change has occurred that two forms (A and B), separated in time and anatomy, once existed.
Overview, including some physiological parameters, of the human circadian rhythm ("biological clock").. Chronobiology is a field of biology that examines timing processes, including periodic (cyclic) phenomena in living organisms, such as their adaptation to solar- and lunar-related rhythms. [1]
Alternation of generations is defined as the alternation of multicellular diploid and haploid forms in the organism's life cycle, regardless of whether these forms are free-living. [6] In some species, such as the alga Ulva lactuca, the diploid and haploid forms are indeed both free-living independent organisms, essentially identical in ...
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]
The biotic environment includes genes, cells, organisms, members of the same species (conspecifics) and other species that share a habitat. [ 172 ] The distinction between external and internal environments, however, is an abstraction parsing life and environment into units or facts that are inseparable in reality.
At the same time, Sahara is green with rivers, lakes, cattle, crocodiles and monsoons. At 8 ka, Common (Bread) wheat (Triticum aestivum) originates in southwest Asia due to hybridisation of emmer wheat with a goat-grass, Aegilops tauschii. At 6.5 ka, two rice species are domesticated: Asian rice, Oryza sativa, and African rice Oryza glaberrima.