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SYMBIOTIC COMPETITION. “Similar kinds of reproductive competition are predicted to occur in some other symbiotic relationships, and possible examples are presented for two of them: bacterial plasmids and endozoic algae." http://www.jstor.org/stable/2824738?seq=1#page_scan_tab_contents View in LinkedIn

COMPETITION WITHIN. "I propose that in certain circumstances natural selection favors intraorganismal reproductive competition between different varieties of organelle DNA, and in other circumstances selection favors competition between organelle and nuclear DNA. Evidence is marshalled to show that such competition occurs in nature. Situations which would lead to selection for both kinds of competition are described and are shown to be relatively common." (1980). http://www.jstor.org/stable/2824738?seq=1#page_scan_tab_contents View in LinkedIn

CELLULAR ECOSYSTEM. "A eukaryotic cell can be likened to a society composed of a nucleus and a crowd of subcellular organelles in which all members cooperate for the common good." https://lnkd.in/dSKRVqw View in LinkedIn

PHENOTYPIC OPTIONS. "The mere fact that organisms are subject to natural selection, so that we only expect to observe organisms with maximal (or nearly maximal) relative fitness, implies that we’ll see trade-offs." https://lnkd.in/dGaAzSA View in LinkedIn

CONSTRAINTS ON PHENOTYPE. "The common theme of all of the above is constraints on phenotypes. Allocation, antagonistic pleiotropy, mutational decay, and the laws of physics are all reasons why organisms can’t build (or can’t maintain, over evolutionary time) certain phenotypes. Trade-offs reflect constraints on the range of phenotypic options that are open to organisms.” https://lnkd.in/dGaAzSA View in LinkedIn

REASONS FOR TRADE-OFFS. "Allocation is a big one: a unit of energy, materials, or time that an organism uses to do one thing (say, build a defensive structure) cannot be used to do something else (say, reproduce). Antagonistic pleiotropy is another big one: a mutation that improves one biological function often degrades another (although this is presumably not an ultimate explanation for trade offs, since one can ask why we expect antagonistic pleiotropy). Mutational decay is a third: a mutation that degrades an unused function (think cave fish eyes) will be selectively neutral." https://lnkd.in/dGaAzSA View in LinkedIn

DEVELOPMENTAL TEST. "When sections are cut from a Drosophila imaginal disc, adjoining cells divide to produce a normal-sized trait, even when the injured disc is placed outside of the environment of the developing larva." http://www.pnas.org/content/95/7/3685.full View in LinkedIn

"THE PRINCIPLE OF ALLOCATION is a basic concept in ecology. The principle of allocation also underlies some aspects of the concept of tradeoffs and typically is considered in terms of energy. As a result, organisms tend to be unable to be simultaneously exceptionally durable, such as in terms of maintaining homeostasis, and at the same time exceptionally fecund, at least in terms of a limited resource budget." https://lnkd.in/dSYMHu9 View in LinkedIn

TRAIT SIZE REGULATION. "The findings we describe bear on an old and still unanswered question in biology, namely, how the absolute and relative sizes of traits are regulated. Numerous experiments on regeneration and transplantation have shown that the final size of appendages and internal organs is regulated autonomously, within the structure itself; size regulation of body parts typically requires no external control." http://www.pnas.org/content/95/7/3685.full View in LinkedIn

TOUGH OLD IDEA. "The concept that, during development, different parts of an organism could be in competition with each other is old, and intuitive, but has proven difficult to demonstrate in practice. One reason for this difficulty may be that resource allocation tradeoffs are difficult to measure in organisms that grow and feed continuously, because changes in demands on developmental resources can be met by changes in resource acquisition." View in LinkedIn