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• Hand and digits evolutionplugin-autotooltip__plain plugin-autotooltip_bigHand and digits evolution
  
  "How the hand and digits originated from fish fins during the Devonian fin-to-limb transition remains unsolved. Controversy in this conundrum stems from the scarcity of ontogenetic data from extant lobe-finned fishes."
  
  Source :
• Auction optimizationplugin-autotooltip__plain plugin-autotooltip_bigAuction optimization
  
  "A major difficulty in designing auctions is that valuations are private and bidders need to be incentivized to report their valuations truthfully. The goal is to learn an incentive compatible auction that maximizes revenue. In a seminal piece of work, Myerson resolved the optimal auction design problem when there is a
• Centrioles (cell biology)plugin-autotooltip__plain plugin-autotooltip_bigCentrioles (cell biology)
  
  Centrioles (a.k.a. Basal bodies) are found in many* cells that have a nucleus. They were discovered when advances in microscopes made it possible to look closely at the inner structure of living cells.
  
  They feature a central cylinder or barrel-like structure, about 450 nm high and 250 nm in diameter, with various 'appendages' attached in a nine-fold symmetrical pattern. It's known that the structure features more than 100 different proteins.
• Tobacco smoking and Parkinson's diseaseplugin-autotooltip__plain plugin-autotooltip_bigTobacco smoking and Parkinson's disease
  
  Beginning in the early 2000s, the results of various studies which examined lifestyle choices as possible factors in the development of Parkinson's disease (PD) began suggesting a strong link with long-term smoking.
  
  A 2016 'review study' which compiled and compared results from groups of earlier research papers, was published in
• Lunar waterplugin-autotooltip__plain plugin-autotooltip_bigLunar water
  
  A large number of experimental studies have confirmed that water (as ice) is present in multiple locations on the Moon. A 2010 study from NASA estimated that there are at least 600 million metric tonnes of ice around the Moon's North pole alone. (
• Avian navigationplugin-autotooltip__plain plugin-autotooltip_bigAvian navigation
  
  Many species of birds can very reliably navigate over large distances, even from places they have never been to, and return to their desired destination, often over hundreds or even thousands of kilometres.
  
  Homing pigeons, for example, can very consistently find their way back to their adopted roosting place - even when they have been physically removed hundreds of kilometres away - and often without any knowledge of the removal route.
• Floral longevityplugin-autotooltip__plain plugin-autotooltip_bigFloral longevity
  
  Flowers allowed to remain on the parent plant tend to last anywhere between 1 to 30 days* in terms of their pollination period. This large variation (x30) in longevity remains unexplained.
  
  "Floral longevity, the length of time a flower remains open and functional, is an important trait in pollination biology. Optimal floral longevities balance flowering costs against the rate of pollen export and receipt."
• Cell deathplugin-autotooltip__plain plugin-autotooltip_bigCell death
  
  "Why living organisms inevitably die and what death even means in terms of physics and dynamical systems are still open questions despite the vast advances in molecular biology. Revealing how some cells die — not through biochemical processes but physics — would help to answer them."
• Heritable primingplugin-autotooltip__plain plugin-autotooltip_bigHeritable priming
  
  Heritable Priming is the name given to the process in which organisms are able to pass on stress-protection from the parent generation to the siblings.
  
  The 'stress' can be physical (one of the original studies investigated how plants' lack of water can protect later generations from drought stress) or bacteriological / viral.
• Ephaptic couplingplugin-autotooltip__plain plugin-autotooltip_bigEphaptic coupling
  
  Ephaptic coupling is a mode of signal transfer between brain neurons. Researchers in the 19th century had suggested that electricity might be influencing interactions between nerve fibres in close proximity to each other. But it wasn't until 1939 that a team from UCL, London, found experimental proof of electrical interaction between two adjacent - but
• Dreamingplugin-autotooltip__plain plugin-autotooltip_bigDreaming
  
  undefined
  
  "The content and purpose of dreams are not yet understood, though they have been a topic of speculation and interest throughout recorded history.
  
  Source : Wikipedia"
  
  Not only is the function of dreaming unknown (if there is one), but there isn't as yet an agreed definition of what it is.
• Rock salt depositsplugin-autotooltip__plain plugin-autotooltip_bigRock salt deposits
  
  Rock salt (a.k.a. Halite) deposits on Earth are extremely common, with many very extensive deposits thousands of metres deep, and probably totaling trillions of tonnes * See note below.
  
  In geological 'textbook' terms, rock salt deposits are normally classed as an
• Deliriumplugin-autotooltip__plain plugin-autotooltip_bigDelirium
  
  "Over 2.6 million adults over the age of 65 develop delirium each year in the United States (US). Delirium is associated with a significant increase in mortality and the US health care costs associated with delirium are estimated at over $164 billion annually.
• Brain sandplugin-autotooltip__plain plugin-autotooltip_bigBrain sand
  
  Brain Sand (a.k.a. corpora arenacea, acervuli, psammoma bodies and pineal concretions ) refers to small (2–3 μm) sand-like calcified grains which are found in the brains of mammals and some birds.
  
  Because the grains are dense bio-mineralization formations, they show up very well on X-ray scans - especially as they tend to clump together, and can form nodules around 1mm across.
• Automaticity a.k.a. 'Autopilot'plugin-autotooltip__plain plugin-autotooltip_bigAutomaticity a.k.a. 'Autopilot'
  
  Most people who routinely drive to and from their workplace will have experienced 'Highway hypnosis' (ref.) at some stage. In other words, arriving at their destination with little or no recollection of the drive.
  
  Leading to the idea that either :

• Cluster headacheplugin-autotooltip__plain plugin-autotooltip_bigCluster headache
  
  "Cluster headache (CH) always involves pain that is one sided (although it can switch sides) and the main defining feature is the association with one or more of the 'cranial autonomic' features normally described as follows: • Reddening and tearing of the eye • A runny or blocked nostril • Droopy eyelid • Constriction of the pupil • Flushing and facial sweating
• Hand and digits evolutionplugin-autotooltip__plain plugin-autotooltip_bigHand and digits evolution
  
  "How the hand and digits originated from fish fins during the Devonian fin-to-limb transition remains unsolved. Controversy in this conundrum stems from the scarcity of ontogenetic data from extant lobe-finned fishes."
  
  Source :
• Golgi Apparatusplugin-autotooltip__plain plugin-autotooltip_bigGolgi Apparatus
  
  The Golgi Apparatus (a.k.a the Golgi Body and Golgi Complex) is an 'oganelle' (small component) found in almost all cells that have a nucleus (i.e. eukaryotic cells).
  
  It packages 'vesicles' (i.e. small packages of protein wrapped in a fatty membrane) and dispatches them to the correct destination within the cell (i.e. outside the nucleus). It is a fundamentally essential part of the 'machinery' of the cell, and therefore of all complex organisms.
• Auction optimizationplugin-autotooltip__plain plugin-autotooltip_bigAuction optimization
  
  "A major difficulty in designing auctions is that valuations are private and bidders need to be incentivized to report their valuations truthfully. The goal is to learn an incentive compatible auction that maximizes revenue. In a seminal piece of work, Myerson resolved the optimal auction design problem when there is a
• Tobacco smoking and Parkinson's diseaseplugin-autotooltip__plain plugin-autotooltip_bigTobacco smoking and Parkinson's disease
  
  Beginning in the early 2000s, the results of various studies which examined lifestyle choices as possible factors in the development of Parkinson's disease (PD) began suggesting a strong link with long-term smoking.
  
  A 2016 'review study' which compiled and compared results from groups of earlier research papers, was published in
• Musical pitch perceptionplugin-autotooltip__plain plugin-autotooltip_bigMusical pitch perception
  
  "Pitch is a perceptual property of sounds that allows their ordering on a frequency-related scale, or more commonly, pitch is the quality that makes it possible to judge sounds as 'higher' and 'lower' in the sense associated with musical melodies. Pitch can be determined only in sounds that have a frequency that is clear and stable enough to distinguish from noise."
• Firefly light display synchronyplugin-autotooltip__plain plugin-autotooltip_bigFirefly light display synchrony
  
  There are many documented accounts (including video footage) of large groups of 'Fireflies' (typically beetles of the Lampyridae family) flashing their bio-luminescent lights in a synchronised display.
  
  It's not known why they have developed the synchronised displays, and recent research is suggesting that the methods used to synchronise are less straightforward than was previously assumed.
• Water - its originplugin-autotooltip__plain plugin-autotooltip_bigWater - its origin
  
  One obvious difference between Earth and other planets in the Solar System is that it's 70% covered in liquid water. There are at least five major (and very different) theories proposing the origins of such a large volume of water (estimated at around 1.3 billion cubic kilometres).
• Lunar waterplugin-autotooltip__plain plugin-autotooltip_bigLunar water
  
  A large number of experimental studies have confirmed that water (as ice) is present in multiple locations on the Moon. A 2010 study from NASA estimated that there are at least 600 million metric tonnes of ice around the Moon's North pole alone. (
• Messinian salinity crisisplugin-autotooltip__plain plugin-autotooltip_bigMessinian salinity crisis
  
  The Messianian Salinity Crisis refers to very large deposits of sea salt found in the Mediterranean region, about 1km below the current sea bed. (Named after Messina, a southern Italian city, where the deposits were first identified)
• Bird Migrationplugin-autotooltip__plain plugin-autotooltip_bigBird Migration
  
  Around 50% of birds migrate (i.e. undertake large-scale routine long distance travel for breeding / feeding).
  
  The distances covered can be huge - e.g. Manx Shearwaters migrate 14,000 km (8,700 mi) each year. The time-triggers, and the methods of route navigation, have been widely investigated, but much of the detail is still unknown.
• Galaxy formationplugin-autotooltip__plain plugin-autotooltip_bigGalaxy formation
  
  There are currently two (mutually exclusive) theories regarding the formation of galaxies, which according to current models, all have a supermassive Black Hole at their centre.
  
  In brief, the theories are that :
  
  1) The galaxy formed around a pre-existing Black Hole which was sufficiently massive as to attract all the nearby stars.
• Cell deathplugin-autotooltip__plain plugin-autotooltip_bigCell death
  
  "Why living organisms inevitably die and what death even means in terms of physics and dynamical systems are still open questions despite the vast advances in molecular biology. Revealing how some cells die — not through biochemical processes but physics — would help to answer them."
• Floral longevityplugin-autotooltip__plain plugin-autotooltip_bigFloral longevity
  
  Flowers allowed to remain on the parent plant tend to last anywhere between 1 to 30 days* in terms of their pollination period. This large variation (x30) in longevity remains unexplained.
  
  "Floral longevity, the length of time a flower remains open and functional, is an important trait in pollination biology. Optimal floral longevities balance flowering costs against the rate of pollen export and receipt."
• Time Awarenessplugin-autotooltip__plain plugin-autotooltip_bigTime Awareness
  
  "Anticipating events that will happen in the future is among the most important functions the brain performs. Indeed, it has been increasingly stressed that learning and memory are prospective brain functions; that is, they are only adaptive to the extent that they help animals anticipate and prepare for the future (Dudai and Carruthers, 2005; Schacter and Addis, 2007). To anticipate when events will happen, the brain has evolved mechanisms to tell time across a wide range of te…