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• W137279594 abstract "perspectives on life span Life span should be considered within a larger biological framework concerned with life duration—a model where the end points of life for an individual do not necessarily correspond to the conventional events of birth PDR 29 Supp Carey.sp 7/6/06, 3:16 PM 1 2 L I F E S P A N : A C O N C E P T U A L O V E R V I E W and death. The concept of life span does not apply to bacteria that reproduce by binary fission, to plant species that reproduce by cloning, or to modular organisms with iterated growth such as coral or honeybee colonies. The state of existence for an individual refers to one of several possible states of living such as “normal state,” metabolic reduction (e.g., hibernation), or arrest (e.g., frozen embryo; dormancy); its time of existence refers to the sum total of all stages of the individual’s life up to its extinction. What constitutes an individual is conditional on the level of individualism. For example, the individual cell within a multicellular organism and the individual worker bee in a colony of honeybees are individuals on one level but are part of a greater whole on another. Death of a component part (e.g., through apoptosis) may or may not determine the death of the whole, although in each case the components (cells; worker bees) relinquish both their evolutionary heritage and their autonomy in favor of the higher organisms (or in the case of honey bees, the colony as “super-organism”) of which they are a part (Michod 1999). The distinction between mortal macroorganisms and immortal microorganisms is unclear with certain organisms. For example, slime molds such as Dictostelium discoideum feed most of the time as millions of individual, potentially immortal single-celled amoeba in the forest soil and litter. Under certain conditions, however, these millions form aggregate “swarms” in dense, coordinated, visible, mortal masses that look slug-like. These aggregates then sprout into a “flower” to create and disseminate spores (Bonner 1967; Murchie 1967). A different life span issue concerns the concept of replacement of constituent parts (i.e., cells). The hydra, Hydra littoralis, replaces all of its cells over the course of a few weeks and thus can potentially live forever (Campbell 1967). When a single reproductive event that occurs at the end of the life course results in the death of the individual, then life span is linked deterministically to the species’ natural history. This occurs with the seed set of annual plants (grasses), in drone (male) honeybees as a consequence of the mechanical damage caused by mating, in many mayfly species when a female’s abdomen ruptures to release her eggs after she drops into a lake or stream, and in anadromous salmon that die shortly after spawning. Life span can be considered indeterminate for species (including humans) that are capable of repeated (iteroparous) reproduction. This concept is consistent with everything that is known about the lack of physiological cutoff points in biology: all evidence suggests that species do not have an internal clock for terminating life. Death and extinction Death is the unique and singular event that ends life. Dying is a graded process in virtually all organisms starting with substages of infirmity (weakPDR 29 Supp Carey.sp 7/6/06, 3:16 PM 2 J A M E S R . C A R E Y 3 ness) and morbidity (sickliness) and progressing to coma, breath stoppage, heart stoppage, brain death, cessation of metabolism, tissue degradation, and loss of DNA integrity. Because of this progression of death by stages, it is useful to distinguish between the death of the organism as a whole, which refers to somatic or organismic death (the organism as an integrated functional unit), and the death of the whole organism, which refers to death of the various tissues and cells (Kass 1983). Whereas the death of the organism as a whole is usually an event—an abrupt crossing-over from the live to the dead state—the death of different parts of the whole organism is a protracted process of degradation. In broader biological contexts, the ways in which individuals can become extinct (as opposed to extinction by dying) as singular entities are through fission in bacteria where one individual becomes two or through fragmentation as in fungi where the filaments of the original fungal growth break into many pieces, each of which is essentially a seed for new growth. A remarkable example is splitting in flatworms where the original individual can be divided into parts, each being capable of growing into a new worm. In each of these cases, the original individual no longer exists; no part or division has precedence over the other. End points and perpetuity Mortal refers to individuals destined to die, immortal refers to individuals living forever (however, it also is used in the context of immortal germ lines), finitude (or finite) refers to limits, infinitude (or infinity) to anything without limits, determinate refers to a fixed process or program, and indeterminate refers to an open-ended process or rate. The term immortalization describes cell cultures that can be propagated generation after generation with no loss of viability (Blackburn 2000) such as the HeLa cell line (the first human cells to live indefinitely outside the body), which was derived from and named after cancer victim Henrietta Lack’s cells in the 1940s (Murchie 1967; Skloot 2001), and immortalized B lymphocytes, which are used to produce virtually unlimited quantities of identical antibody molecules (Kohler and Milstein 1975). The term preservation refers to maintenance in the existing state. The bacteria trapped in 25–30-million-year-old amber (Cano and Borucki 1995) or in a 250-million-yearold primary salt crystal (Vreeland et al. 2000) and the mitochondrial DNA isolated from a 29,000-year-old Neanderthal (Ovchinnkov et al. 2000) are all examples of preservation. Cryopreservation is a special type of preservation using ultra-low temperatures (–196o C) to preserve human sperm and embryos (Silver 1998; Trounson 1986). Dormancy describes any one of a number of evolved types of arrested growth ranging from torpor to hibernation (Carson and Stalker 1947; Hairston and Caceres 1996; Mansingh 1971; Masaki 1980). PDR 29 Supp Carey.sp 7/6/06, 3:16 PM 3 4 L I F E S P A N : A C O N C E P T U A L O V E R V I E W" @default.
• W137279594 created "2016-06-24" @default.
• W137279594 creator A5012511933 @default.
• W137279594 creator A5054164624 @default.
• W137279594 date "2003-01-01" @default.
• W137279594 modified "2023-09-24" @default.
• W137279594 title "Life span : evolutionary, ecological, and demographic perspectives" @default.
• W137279594 cites W131983162 @default.
• W137279594 cites W1514533495 @default.
• W137279594 cites W1524525825 @default.
• W137279594 cites W1532858913 @default.
• W137279594 cites W1538443123 @default.
• W137279594 cites W1540286737 @default.
• W137279594 cites W1542797548 @default.
• W137279594 cites W1544815196 @default.
• W137279594 cites W1552856649 @default.
• W137279594 cites W155905007 @default.
• W137279594 cites W1566314769 @default.
• W137279594 cites W1566634393 @default.
• W137279594 cites W1582541805 @default.
• W137279594 cites W1593139096 @default.
• W137279594 cites W1601417721 @default.
• W137279594 cites W1607529401 @default.
• W137279594 cites W1639847869 @default.
• W137279594 cites W1670075887 @default.
• W137279594 cites W1678060042 @default.
• W137279594 cites W1737257822 @default.
• W137279594 cites W1964832668 @default.
• W137279594 cites W1965007097 @default.
• W137279594 cites W1969498530 @default.
• W137279594 cites W1969946603 @default.
• W137279594 cites W1970031354 @default.
• W137279594 cites W1972067231 @default.
• W137279594 cites W1980577245 @default.
• W137279594 cites W1983155510 @default.
• W137279594 cites W1984236954 @default.
• W137279594 cites W1986857932 @default.
• W137279594 cites W1988643163 @default.
• W137279594 cites W1990276200 @default.
• W137279594 cites W1990380024 @default.
• W137279594 cites W1990630927 @default.
• W137279594 cites W1991408099 @default.
• W137279594 cites W1991519591 @default.
• W137279594 cites W1995424845 @default.
• W137279594 cites W2005888265 @default.
• W137279594 cites W2006333167 @default.
• W137279594 cites W2006384398 @default.
• W137279594 cites W2006395975 @default.
• W137279594 cites W2008428406 @default.
• W137279594 cites W2008505874 @default.
• W137279594 cites W2008643117 @default.
• W137279594 cites W2008659241 @default.
• W137279594 cites W2009028587 @default.
• W137279594 cites W2011352194 @default.
• W137279594 cites W2013923928 @default.
• W137279594 cites W2023095530 @default.
• W137279594 cites W2025355955 @default.
• W137279594 cites W2026853124 @default.
• W137279594 cites W2027960843 @default.
• W137279594 cites W2028114397 @default.
• W137279594 cites W2032467890 @default.
• W137279594 cites W2033072394 @default.
• W137279594 cites W2033374666 @default.
• W137279594 cites W2033872641 @default.
• W137279594 cites W2034305622 @default.
• W137279594 cites W2036419021 @default.
• W137279594 cites W2038385776 @default.
• W137279594 cites W2038584209 @default.
• W137279594 cites W2042834342 @default.
• W137279594 cites W2045668377 @default.
• W137279594 cites W2047752581 @default.
• W137279594 cites W2049009766 @default.
• W137279594 cites W2049107009 @default.
• W137279594 cites W2050960442 @default.
• W137279594 cites W2054164550 @default.
• W137279594 cites W2056124784 @default.
• W137279594 cites W2056478998 @default.
• W137279594 cites W2062542842 @default.
• W137279594 cites W2062629127 @default.
• W137279594 cites W2063809442 @default.
• W137279594 cites W2064196546 @default.
• W137279594 cites W2068344138 @default.
• W137279594 cites W2068524195 @default.
• W137279594 cites W2072168063 @default.
• W137279594 cites W2072652164 @default.
• W137279594 cites W2074540478 @default.
• W137279594 cites W2078622873 @default.
• W137279594 cites W2086260067 @default.
• W137279594 cites W2087161045 @default.
• W137279594 cites W2088017232 @default.
• W137279594 cites W2088277595 @default.
• W137279594 cites W2088609197 @default.
• W137279594 cites W2088655169 @default.
• W137279594 cites W2088891796 @default.
• W137279594 cites W2089428701 @default.
• W137279594 cites W2090081972 @default.
• W137279594 cites W2094243809 @default.
• W137279594 cites W2102198565 @default.
• W137279594 cites W2106619606 @default.
• W137279594 cites W2107055065 @default.

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