Floris van Breugel / Temple Crag above Second lake, one the of the Big Pine lakes below the Palisade basin, John Muir Wilderness, Sierra Nevada, California, USA, May

Simon Colmer / Green-veined White butterfly egg (Pieris napi) above, Orange-tip butterfly egg (Anthocharis cardamines) below, on Garlic mustard (Alliaria petiolata) Sussex, UK. June.

Ole Jorgen Liodden / Man resting by tree with small fire, with Northern Lights in the sky above, Valdres, Norway, January 2005.

Denis-Huot / African elephant (Loxodonta africana) herd at sunset, Masai-Mara Game Reserve, Kenya. January.

Denis-Huot / Wildebeest (Connochaetes taurinus) herd below stormy sky during migration, Masai-Mara game reserve, Kenya.

Pascal Kobeh / Female humpback whale (Megaptera novaeangliae) with its very young calf at the surface, Rurutu island, Australs Archipelago, French Polynesia. Pacific Ocean.

Alex Mustard,Alex Mustard / Green surf anemones (Anthopleura xanthogrammica) grow in shallow water below the temperate rain forest. Browning Pass, Port Hardy, Vancouver Island, British Columbia, Canada. North East Pacific Ocean.

David Tipling / 2020VISION / Barn Owl (Tyto alba) female hunting over grazing marsh, Burnham Overy, Norfolk, UK, February. Did you know? During flight, the left ear of the barn owl captures sounds below while the right ear focuse...

Bryan and Cherry Alexander / Tabular iceberg showing the portion underwater that is sculpted by the sea. Polar regions. Digitally created image composite

Bryan and Cherry Alexander / Ice arch iceberg showing the portion underwater that is sculpted by the sea. Polar regions. Digitally created image composite

Solvin Zankl / A Costa Rican researcher monitors the temperature in the developing sea turtle nests at Ostional beach, Costa Rica, November 2009. ^^^ Sea turtles have, like many other reptiles, temperature-dependent...

Nigel Cattlin / Wheat (Triticum aestivum) seeds germinating with development of roots and shoots, above and below ground.

Nigel Cattlin / Wheat (Triticum aestivum) seeds germinating with development of roots and coleoptile covering of shoots. Image above and below ground.

Nigel Cattlin / Peach (Prunus persica) tree sapling, roots and stem growing from stone, above and below ground.

Nigel Cattlin / Maize (Zea mays) seedling with roots and early leaves, above and below ground.

Nigel Cattlin / Maize (Zea mays) seedling with roots and early leaves, above and below ground.

Nigel Cattlin / Broad bean (Vicia faba), young plant with germinated seed, early leaves and roots, above and below ground.

Nigel Cattlin / Sunflower (Helianthus annuus) seedlings in different stages of germination from seed to seedling with cotyledons, above and below ground. Sequence.

Nigel Cattlin / Sunflower (Helianthus annuus) seedling with cotyledons expanding, above and below ground. Sequence 5/5.

Nigel Cattlin / Sunflower (Helianthus annuus) seedling with cotyledons expanding, pericarp still attached to leaf. Above and below ground. Sequence 4/5.

Nigel Cattlin / Sunflower (Helianthus annuus) seedling with cotyledons expanding, leaves still trapped by pericarp. Above and below ground. Sequence 3/5.

Nigel Cattlin / Sunflower (Helianthus annuus) seed within pericarp / seed coat, radicle developing. Above and below ground. Sequence 2/5.

Nigel Cattlin / Sunflower (Helianthus annuus) seed in soil, prior to germination and growth, above and below ground. Sequence 1/5.

Heather Angel / Himalayan balsam (Impatiens glandulifera), dissection of flowers. Male phase above, downward projecting stamens release pollen onto backs of bumblebees and honey bees. Female phase below with downward...

Heather Angel / Elephant yam (Amorphophallus paeoniifolius) spathe with band of male flowers above and female flowers below. In cultivation.

Heather Angel / Chinese meadow-rue (Thalictrum delavayi) flowers. Male phase below with stigmas hanging below immature stigmas, female phase above after stamens have fallen. Sha Chong He River Valley, near Danba, Sic...

Graham Eaton / Conglomerate at the unconformity between the Carboniferous limestone below and the Triassic sandstone above at Sully, near Cardiff, South Glamorgan, Wales, UK. September.

Jack Dykinga / Aurora Borealis above taiga with reflection in lake below. Northwest Territories, Canada. September 2018.

Staffan Widstrand / Wild Wonders of China / Bamboo above and a fan palm leaf below, East Lake Greenway park, Wuhan, Hubei, China

Graham Eaton / Kelvin-Helmholz clouds forming over the Eastuary of the River Dee and the Wirral Peninsular, December. These waveform clouds are caused by shear between air above moving at a different speed than belo...

Tony Wu / Humpback whale (Megaptera novaeangliae australis) courtship, with the female above showing her abdomen and the male below. Vava'u, Tonga. Pacific Ocean.

Franco Banfi / Sperm whale (Physeter macrocephalus) tail fluke above water as it dives below a rainbow, Dominica, Caribbean Sea, Atlantic Ocean, Vulnerable species. Digital composite.

Alex Mustard / Spinner dolphins (Stenella longirostris) male below is about to mate with a female, above. Sataya Reef, Fury Shoal, Egypt. Red Sea

Julian Hume / View of Diamond Crater, Oahu, around 1000 years ago. King Kong finch (Chloridops regiskongi) flying past an Oahu palmcreeper (Ciridops sp) perched. Extinct 1892. Directly behind, an O'ahu O'o (Moho ap...

Julian Hume / Ula-ai-hawane (Ciridops anna) pair (female above, male below) of (Extinct 1892). Feeding in the crown of a Pritchardia palm with Mamo (Drepanis pacifica) (Extinct 1898)

Julian Hume / Comparison of Giant Scimitar-billed Nukupu'u (Hemignathus vorpalis) (below), compared with adult males of Akiapola'au (Hemignathus munroi) (Extant, endangered) (above) and Kauai Nukupu'u (Hemignathus...

Julian Hume / Illustration of extinct birds Wahi grosbeak (Chloridops wahi) (above) and the King kong finch (C. regiskongi) (below) feeding on the fruit of Sandalwood (Santalum freycinetianum) on O'ahu, Hawaii.

Julian Hume / Illustration of extinct birds Kioea (Chaetoptila angustipluma) (Extinct 1859) above, with Hawai'i O'o (Moho nobilis) (Extinct 1902) (below) on a flowering Ohia (Metrosideros polymorpha)

Julian Hume / Illustration of extinct male Kaua'i palmcreeper (Ciridops tenax) (above) and a female (below) feed in the crown of a Loulu palm (Pritchardia sp)

Alex Mustard / Ornate ghost pipefish (Solenostomus paradoxus) the larger female is above, her pelvic fins are cupping a clutch of eggs, male below, Dauin, Negros Island, Philippines. Bohol Sea, Pacific Ocean.

David Tipling / Split level view of above and below the water on the Polperro coast Cornwall, UK July

Franco Banfi / Roca Partida above and below sea level with divers - a small rock island covered in white bird guano in the Revillagigedo Archipelago Biosphere Reserve, Socorro Islands, Western Mexico. Composite s...

Wim van den Heever / Umbrella Thorn tree (Vachellia tortilis) at night with campsite below and stars above, Lake Ndutu Tanzania

Alex Hyde / Emerald damselflies (Lestes sponsa) mating, with male above. Peak District National Park, Derbyshire, UK. September.

Martin Willis / Star Finch (Neochmia ruficauda) female above and male below, Kununurra, Kimberley, Western Australia, Australia

Angelo Gandolfi / Large-billed terns (Phaetusa simplex) in non-breeding plumage (above) and breeding plumage (below), Santa Catarina, Brazil, September.

Charlie Summers / Andromeda galaxy and and sister galaxies M110 above and M32 below. Taken from eastern Colorado, USA, September 6-7 2013. Image taken with digital image stacking.

Alex Mustard / Female Mosquito fish (Gambusia affinis) swimming above weeds, below the surface of Lago Baratz, Sardinia, Italy. This species is originally from the Americas, but has been introduced into many countri...

Franco Banfi / Blue shark (Prionace glauca) viewed from below, with Snell's window light effect above, Pico Island, Azores, Portugal, Atlantic Ocean, December

Charlie Summers / The Moon (waning crescent) with Venus (below) and Jupiter (above) as seen 50 minutes before a 0545 sunrise on the morning of 15 July 2012 from Aurora, Colorado, USA

Charlie Summers / The Moon (waning crescent) with Venus (below) and Jupiter (above) as seen just before sunrise on the morning of 15 July 2012 from Aurora, Colorado, USA

Jack Dykinga / Calcium carbinate hoodoos with reflected light of dawn above the conifer lined valley below, Bryce Canyon National Park, Utah, USA

Norbert Wu / Tourists near iceberg showing above and below water, Palmer Station, Antarctic Peninsula, Antarctica

Alex Hyde / Red algae living just below the surface of snow, known as 'Red Snow'. The red pigment provides protection from ultra-violet light. Austrian Alps, 2800 metres above sea level, June 2009.

Bryan and Cherry Alexander / Melting iceberg showing the portion underwater that is sculpted by the sea. Polar regions. Digitally created image composite

Bryan and Cherry Alexander / Melting iceberg showing the portion underwater that is sculpted by the sea. Polar regions. Digitally created image composite

Bryan and Cherry Alexander / Peaks of the Ellsworth Mountains, with orographic clouds above and blue ice below. Antarctica, January 2006.

Axel Gomille / Sloth Bears (Melursus ursinus), adult female (above) and sub-adult male (below) fighting on a tree. Karnataka, India, March.

Nick Upton / Overview of tourists on boardwalk and bridges, dwarfed by the Great waterfall (Veliki Slap) above and Sastavci waterfall below them, Plitvice Lakes National Park, Croatia, July 2010.

Jeff Rotman / Striped butterflyfish (Chaetodon fasciatus) in foresground with Checkerboard wrasse (Halichoeres hortulanus) above and Cleaner wrasse below, Sinai Peninsula, Red Sea, Egypt

Alex Mustard / A Manta ray (Manta birostris) hovering above a cleaning station on a coral reef, while a diver photographs it from below. Raja Ampat, West Papua, Indonesia. March

Alex Mustard / A Manta ray (Manta birostris) hovering above a cleaning station on a coral reef, while a diver photographs it from below. Raja Ampat, West Papua, Indonesia. March

Solvin Zankl / A Costa Rican researcher monitors the temperature in the developing Olive Ridley sea turtle nests at Ostional beach, Costa Rica, November 2009. ^^^ Sea turtles have, like many other reptiles, temperat...

Nick Garbutt / Tomato Frogs (Dyscophus antongilii) mating in amplexus posture, marsh habitat on edge of rice paddy. Smaller male (above) and female (below) Near Maroantsetra, north east Madagascar.

Steven David Miller / Pair of Galah cockatoos (Eolophus / Cacatua roseicapillus) female above, and male below, at nesting hole in dead tree,Coward Springs Station, Oodnadatta Track, South Australia

Aflo / Y-8901 Aerial view of clouds above and below mountain peaks

Nick Upton / Marbled white butterflies (Melanargia galathea) mating on grass stem, female above, male below. Wiltshire, UK, June.

Wild Wonders of Europe / Maitland / Forest edge and upland pasture just below the cloud line above Stenje village region of Lake Macro Prespa, Galicica National Park, Macedonia, June 2009

Wild Wonders of Europe / Giesbers / Fresh snow above tree line with mist rising from below, European larch trees (Larix decidua) growing on mountain side, Liechtenstein, June 2009

Wild Wonders of Europe / Benvie / Cut meadows with small barns above forests, clouds below, near Fliess, Naturpark Kaunergrat, Tirol, Austria, July 2008

Tim Laman / Four-eyed fish (Anableps sp) in very shallow water on mudflats adjacent to mangroves. Caroni Bird Sanctuary, Trinidad, Trinidad and Tobago. These fish have specialized eyes divided into two parts for...

Tim Laman / Four-eyed fish (Anableps sp) in very shallow water on mudflats adjacent to mangroves. Caroni Bird Sanctuary, Trinidad, Trinidad and Tobago. These fish have specialized eyes divided into two parts for...

Jane Burton / Swordtail {Xiphophorus helleri} male Tuxedo lyre-tail (below) and female Red lyre-tail (above), captive, from Central America

Nature Production / Smaller Longheaded Locust male (above) and female (below) {Atractomorpha lata} Japan

Vivek Menon / Above: fake Indian rhinoceros horn base - buffalo horn instead. Below: Real Indian rhinoceros horn (Rhinoceros unicornis)

Pete Oxford / Amukta Island with volcano looming above clouds, with Northern fulmars in flight below, Aleutian Islands, Alaska, USA

Pete Oxford / Amukta Island with volcano looming above clouds, with Northern fulmars in flight below, Aleutian Islands, Alaska, USA

Chris Newbert / Crown-of-thorns Starfish (Acanthaster planci) leg detail showing sharp toxic spines above and suction-cup feet below, Kona, Hawaii

Norbert Wu / Above and below water view of coral reef and tropical island, Solomon Islands

Norbert Wu / Above and below water view of coral reef and tropical island, Solomon Islands

Norbert Wu / West Indian Manatee (Trichechus manatus) above and below water view, Crystal River, Florida

Norbert Wu / Adelie Penguin (Pygoscelis adeliae) above and below water orcas-eye view of group on ice floe that has split off of ice edge, McMurdo Sound, Antarctica

Fred Bavendam / Above and below water view of a garden of hard corals just beneath the water's surface and sunset at Bunaken Island, North Sulawesi, Indonesia

Fred Bavendam / Above and below water view of a garden of hard corals just beneath the water's surface and sunset at Bunaken Island, North Sulawesi, Indonesia

David Cottridge / Great tit {Parus major} above and Blue tit {Parus caeruleus} below, Essex, UK.

Tim Edwards / Plant life growing below and above tide line - from bottom: seaweed in inter-tidal zone, then black lichen, yellow lichen and green Samphire. Co Kerry, Republic of Ireland.

Paul D Stewart / Illustration frontispiece from Thomas Burnet's 'The Sacred Theory of the Earth' 1684, the most popular geological work of the 17th century. Christ stands aside the full cycle of creation with the epit...

Nick Upton / Channelled wrack (Pelvetia canaliculata) above and Spiral / Flat wrack (Fucus spiralis) below, growing on rocks high on the shoreline, exposed at low tide. Rhossili, The Gower Peninsula, UK, July.

Rick Tomlinson / Eastbourne Lifeboat passes the Beachy Head Lighthouse. Beachy Head rises 162 metres (530 feet) above the sea below and is the highest chalk sea cliff in Britain, this is the most famous part of the Ea...

Pete Oxford / Red Mangrove (Rhizophora mangle) above and below water, Jardines de la Reina National Park, Cuba

Julian Hume / Illustration of Mauritian birds. Mauritius pink pigeon (Nesoenas mayeri) (centre left); Mauritius fody (Foudia rubra) (centre right); Mauritius olive white-eye (Zosterops chloronothos) feeding on the...

Julian Hume / Illustration of blue morphs (usually green) of Rodrigues parakeet / Newton's parakeet (Psittacula exsul) - extinct 1874. Feeding on hibiscus lilliflorus (above) and Syzygium balfouri (below). Island o...

Emmanuel Rondeau / Beech marten (Martes foina) entering a wildlife underpass below the A87 highway and above the Natteries brook at night, Maine-et-Loire, France. May. Camera trap.

Emmanuel Rondeau / Rabbit (Oryctolagus cuniculus) using a wildlife underpass below the A83 highway and above the Blaison river, Vendee, France. May. Camera trap.

Emmanuel Rondeau / Fox (Vulpes Vulpes) using a wildlife underpass below the A64 highway and above the Rieu-tort brook at night, Hautes-Pyrenees, France. June. Camera trap image.

Emmanuel Rondeau / Stoat (Mustela erminea) standing on a wildlife underpass below the A89 highway and above the Deirot river, Correze, France. October. Camera trap image.