These are recent changes to Wikenigma
Newest at the top. Click links to view . . .

• Insect flight evolutionplugin-autotooltip__plain plugin-autotooltip_bigInsect flight evolution
  
  "Sometime in the Carboniferous Period, some 350 to 400 million years ago, when there were only two major land masses, insects began flying. How and why insect wings developed is not well understood, largely due to the scarcity of appropriate fossils from the period of their development in the Lower Carboniferous."
• 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 :
• Human Evolutionplugin-autotooltip__plain plugin-autotooltip_bigHuman Evolution
  
  "[...] over the past 15 years, almost every part of our story, every assumption about who our ancestors were and where we came from, has been called into question. The new insights have some unsettling implications for how long we have walked the earth, and even who we really are.
• Flowering plants evolutionplugin-autotooltip__plain plugin-autotooltip_bigFlowering plants evolution
  
  The evolutionary pathways that produced the flowering plants (the Angiosperms) have been studied for at least 140 years.
  
  The flowering plants appear very suddenly (geologically speaking) in the fossil record, at around 100 million years ago. Before that, all known plants were
• Feather evolutionplugin-autotooltip__plain plugin-autotooltip_bigFeather evolution
  
  It has been known since the mid 1800s that many species of dinosaur had 'feathers'. Until the 1970s, it was widely assumed that the evolution of feathers happened concurrently as animals became able to 'glide' or fly.
  
  In the 1970s, fossils of several species of
• Avian flight evolutionplugin-autotooltip__plain plugin-autotooltip_bigAvian flight evolution
  
  It's now widely agreed that modern-day birds evolved, during the Mesozoic Era, from dinosaur species which survived the Cretaceous / Tertiary extinction event. (See: Avian K-T survival )
  
  But the question of how and why birds acquired the ability to fly is still being debated.
• Cell sizeplugin-autotooltip__plain plugin-autotooltip_bigCell size
  
  A detailed explanation of the factors which regulate cell size (i.e. the size to which cells grow) has not yet been found. Since (most) cells stop growing when they reach a specific size, it's suggested that there must be some feedback mechanism to restrict growth beyond that point.
• The Nuclear Matrixplugin-autotooltip__plain plugin-autotooltip_bigThe Nuclear Matrix
  
  First described in 1948, the Nuclear Matrix refers to a network of fibres found inside the nucleus of all animal, plant, fungi and bacterial (etc.) cells, It has also been termed the “Nuclear-Scaffold” or "NuMat".
  
  The function of the matrix is disputed. Some theorists suggest that it's an active structure involved in biochemical and genetic transport - as it contains proteins, chaperones, DNA/RNA-binding proteins, chromatin remodeling and transcription factors (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.
• 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.
• Cellular vaultsplugin-autotooltip__plain plugin-autotooltip_bigCellular vaults
  
  Vaults are microscopic structures found in nearly all cells which have a nucleus. They were first seen in 1986 using electron microscope 'negative staining' techniques.(ref.)
  
  They are highly regular in structure, made of specialsed proteins, and with a strict 36-fold symmetry (
• Cellular organellesplugin-autotooltip__plain plugin-autotooltip_bigCellular organelles
  
  Eukaryotic cells are cells which have a nucleus. Within that nucleus are various discrete structures with very specific functions that are, as a group, called 'organelles'.
  
  In the 1970s a book by professor Lynn Margulis (titled Origin of Eukaryotic Cells)
• Life on Earth (timespan)plugin-autotooltip__plain plugin-autotooltip_bigLife on Earth (timespan)
  
  There is currently no scientific agreement as to how long ago life on Earth evolved. Estimates, based on geological evidence, vary by about 200 million years - from between 3.85 billion years ago (Ga), and 3.65 Ga..
  
  To date, the oldest undisputed fossils appear in rocks from 3.2 Ga, but recent carbon-dating techniques applied to rocks from
• Primordial Soupplugin-autotooltip__plain plugin-autotooltip_bigPrimordial Soup
  
  "In 1953 an iconic set of experiments showed that some of the chemical building blocks of life, such as amino acids, could form spontaneously in the atmospheric conditions thought to prevail on the primordial Earth. This gave rise to the idea that the early oceans were a "primordial soup" from which life somehow emerged.
• 'Borg' DNAplugin-autotooltip__plain plugin-autotooltip_big'Borg' DNA
  
  'Borgs' are newly discovered (2021) large functional DNA sequences found in the cell nucleus, but outside the chromosomes.
  
  They have been found, in abundance, in some species of the micro-organisms Archaea - in particular, ones which can oxidise and remove methane from the environment. On a global scale, the activities of these organisms are crucial for controlling methane levels (methane being a naturally occurring and powerful 'Greenhouse Gas').

• 'Borg' DNAplugin-autotooltip__plain plugin-autotooltip_big'Borg' DNA
  
  'Borgs' are newly discovered (2021) large functional DNA sequences found in the cell nucleus, but outside the chromosomes.
  
  They have been found, in abundance, in some species of the micro-organisms Archaea - in particular, ones which can oxidise and remove methane from the environment. On a global scale, the activities of these organisms are crucial for controlling methane levels (methane being a naturally occurring and powerful 'Greenhouse Gas').
• Nematocytes mechanismsplugin-autotooltip__plain plugin-autotooltip_bigNematocytes mechanisms
  
  Nematocytes (a.k.a nematocysts, cnidocysts or cnidae) are the stinging cells found in jellyfish, hydra, sea anemones &etc.
  
  "Though an enormous amount of work has been done on nematocysts, the problem of how they are discharged remains unsolved. There are really two separate problems. First, what is the natural stimulus which excites the cnidoblast; second, what is the physical mechanism by which the nematocyst itself discharges? There is more work on the mechanics of di…
• Cushing's diseaseplugin-autotooltip__plain plugin-autotooltip_bigCushing's disease
  
  Cushing's disease, (a.k.a Cushing's syndrome and hypercortisolism ) is a rare, life-threatening, hormonal imbalance disorder.
  
  "Cushing's syndrome, also called hypercortisolism, is a rare endocrine disorder caused by chronic exposure of the body's tissues to excess levels of cortisol - a hormone naturally produced by the adrenal gland. Exposure to too much cortisol can occur from long-term use of synthetic glucocorticoid hormones to treat inflammatory illnesses. Pituitary ade…
• Hadamard conjectureplugin-autotooltip__plain plugin-autotooltip_bigHadamard conjecture
  
  "A Hadamard matrix is a type of square (-1,1)-matrix invented by Sylvester (1867) under the name of anallagmatic pavement, 26 years before Hadamard (1893) considered them. In a Hadamard matrix, placing any two columns or rows side by side gives half the adjacent cells the same sign and half the other sign. When viewed as pavements, cells with 1s are colored black and those with
• 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
• 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."