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Visualizzazione post con etichetta extinction. Mostra tutti i post
Visualizzazione post con etichetta extinction. Mostra tutti i post

giovedì 25 giugno 2020

# life: a paradigm shift; extinction vs. evanescence, relict species, ...

<< The first "complete" paradigm of extinction was proposed as "the multigenerational, attritional loss of reproductive fitness," for which MALF is a suitable acronym. A "complete" paradigm must encompass cause, effect, and a mechanism. The primary goal of this study is to verify the new paradigm. (AA) cite four independent tests of the paradigm employing observational, experimental, and wholly theoretical techniques, >>

<< "extinction" presents certain problems with adjectival and gerund forms. (AA) do not refer to a process of "extinctioning" or "extincting" and there is no disciplinary field named "extinctionary" biology, ecology, or genetics. There are several possible verbs for extinction that treat the population or species as agent. These include "devolve," "senesce," "die off," "terminate," and "disappear," among others. However, all of these are in common use with connotations that would distract from (they) proposed meaning. "Devolve" is common in antievolutionist literature. "Senesce" is usually applied only to individuals. "Die off" does not have a single-word noun form. "Terminate" used intransitively comes close to our proposed meaning, but the popularity of the Arnold Schwarzenegger film Terminator will suggest the transitive form to most people. "Disappear" suggests something that is merely out of sight, not necessarily extinct. Instead of these common words, (they) propose using a verb with no distracting connotations. (AA) take our cue from Jefferson’s concern over extinction. Jefferson (1799:256) uses the term "evanish," or in its modern form, "vanish." The adjectival form "vanished" is usable but the noun form sounds a bit awkward: "vanishment." However, Jefferson’s "evanish" calls attention to the Latin root, e + vanescere = to pass away. "Evanesce" has an elegant noun form, "evanescence," and several adjectival forms covering a range of states: "evanesced" denoting the completed action, "evanescing" denoting an action in process, and "evanescent" denoting action in process or in potential. In physics, the adjective "evanescent" is used to designate an electromagnetic field that does not propagate waves beyond the vicinity of the source of the field. Physics and biology are sufficiently distinct that (AA) proposed usage would not create confusion. "Evanescence" does not imply an external agent performing the action and fits the understanding of extinction as a process without adding confusing connotations. This process may be a precursor or complement to evolution, but not necessarily so. >>

Delbert Wiens, Timothy Sweet, Thomas Worsley. Validating the New Paradigm for Extinction: Overcoming 200 Years of Historical Neglect, Philosophical Misconception, and Inadequate Language. The Quarterly Review of Biology. Vol. 95, Issue 2, Pages 109-124. doi: 10.1086/709086. Jun 2020.


Goodbye 'extinction,' hello 'evanescence'? Validating a new paradigm. University of Chicago. Jun 18, 2020. 



sabato 23 maggio 2020

# evol: apropos of a big mystery; Neanderthal may have been surrounded and terminated (killed) by Sapiens competition (and/or probably by Sapiens multitudes, their viruses, their chatter, ...)

<< Climate scientists from the IBS Center for Climate Physics discover that, contrary to previously held beliefs, Neanderthal extinction was neither caused by abrupt glacial climate shifts, nor by interbreeding with Homo sapiens. According to new supercomputer model simulations, only competition between Neanderthals and Homo sapiens can explain the rapid demise of Neanderthals around 43 to 38 thousand years ago. >>

Supercomputer model simulations reveal cause of Neanderthal extinction. Institute for Basic Science. May 20, 2020.


<< Anatomically Modern Humans are the sole survivor of a group of hominins that inhabited our planet during the last ice age and that included, among others, Homo neanderthalensis, Homo denisova, and Homo erectus. Whether previous hominin extinctions were triggered by external factors, such as abrupt climate change, volcanic eruptions or whether competition and interbreeding played major roles in their demise still remains unresolved. (..)  a realistic extinction of the Neanderthal population can only be simulated when Homo sapiens is chosen to be considerably more effective in exploiting scarce glacial food resources as compared to Neanderthals. >>

Axel Timmermann. Quantifying the potential causes of Neanderthal extinction: Abrupt climate change versus competition and interbreeding. Quaternary Science Reviews. 
Volume 238, 15 June 2020, 106331. May 15, 2020. 


Also

keyword 'Neanderthal' in FonT



giovedì 14 maggio 2020

# ecol: when a predator could help his prey to adapt to an uncertain future (among the fly Iteomyia salicisverruca) ...

<< The loss of biodiversity is rewiring the web of life; however, it is uncertain how this will affect the ability of remaining populations to evolve and adapt to future environments. >>

AA << conducted a field experiment that either maintained a natural community of predators or removed all but one of the predators that was able to impose selection on a common prey. (They) found that the loss of predators acted to constrain prey evolution toward a particular combination of traits. Moreover, (they) found that the loss of predators could make it more difficult for prey to adapt to uncertain future environments. Taken together, (these) results suggest that the simplification of the web of life may constrain the adaptive potential of remaining populations. >>

Matthew A. Barbour, Christopher J. Greyson‐Gaito, et al. Loss of consumers constrains phenotypic evolution in the resulting food web. Evolution Letters. doi: 10.1002/ evl3.170. Apr 20, 2020. 


<< Thinking about the big picture, our study hints at a potential insidious side effect of extinctions, (..) The extinction of natural enemies may compromise the ability of remaining species to adapt and persist in an uncertain and changing world. If this is true, this would put many ecosystems at even greater risk than we currently realize. >> Matthew A. Barbour.

Predators help prey adapt to an uncertain future. University of Zurich. 
 May 4, 2020




giovedì 20 febbraio 2020

# life: the fate of humans and insects intertwine

<< The fate of humans and insects intertwine, especially through the medium of plants. >>

Michael J.Samways, Philip S.Barton, et al. Solutions for humanity on how to conserve insects. Biological Conservation. Volume 242, 108427,  Review. Feb 9, 2020.

https://www.sciencedirect.com/science/article/pii/S0006320719317793

Damian Carrington. Fates of humans and insects intertwined, warn scientists. Experts call for solutions to be enforced immediately to halt global population collapses. Feb 20, 2020.

https://www.theguardian.com/environment/2020/feb/20/fates-humans-insects-intertwined-scientists-population-collapse

Also

the beetle Carabaeus lamarcki, dancer and sky analyzer.  May 14, 2016.

https://flashontrack.blogspot.com/2016/05/s-behav-beetle-carabaeus-lamarcki.html