Natural History and Life Time Line: Butterflies the Flying Jewels
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Mumbai University, S.B.Sc. Zoology, Sem III Paper-USZO303, Year 2017-18 S.Y.B.Sc. Zoology Elective Course, USZO303 Unit I- Amazing Animals 1.1. Natural History Natural History and Life time line: The Earth is a little over 4.5 billion years old, its oldest materials being 4.3 billion-year-old zircon crystals. Its earliest times were geologically violent, and it suffered constant bombardment from meteorites. When this ended, the Earth cooled and its surface solidified to a crust - the first solid rocks. There were no continents as yet, just a global ocean peppered with small islands. Erosion, sedimentation and volcanic activity - possibly assisted by more meteor impacts - eventually created small proto- continents which grew until they reached roughly their current size 2.5 billion years ago. The continents have since repeatedly collided and been torn apart, so maps of Earth in the distant past are quite different to today's. The history of life on Earth began about 3.8 billion years ago, initially with single-celled prokaryotic cells, such as bacteria. Multicellular life evolved over a billion years later and it's only in the last 570 million years that the kind of life forms we are familiar with began to evolve, starting with arthropods, followed by fish 530 million years ago (Ma), land plants 475Ma and forests 385Ma. Mammals didn't evolve until 200Ma and our own species, Homo sapiens, only 200,000 years ago. So humans have been around for a mere 0.004% of the Earth's history. Geological timeline: During its dramatic 4.5 billion year history, Earth has gone through a series of major geological and biological changes. The timescale below highlights a number of notable prehistoric events and the geological periods in which they occurred. As things didn't get interesting from a biological perspective until around 570 million years ago, we've included a couple of zoomed in timelines to show the detail of more recent evolutionary history. Geologists have organised the history of the Earth into a timescale on which large chunks of time are called periods and smaller ones called epochs. Each period is separated by a major geological or palaeontological event, such as the mass extinction of the dinosaurs which occurred at the boundary between the Cretaceous period and the Paleocene epoch. Although the Cretaceous-Tertiary (or K-T) extinction event is the most well-known because it wiped out the dinosaurs, a series of other mass extinction events has occurred throughout the history of the Earth, some even more devastating than K-T. Mass extinctions are periods in Earth's history when abnormally large numbers of species die out simultaneously or within a limited time frame. The most severe occurred at the end of the Permian period when 96% of all species perished. This along with K-T are two of the Big Five mass extinctions, each of which wiped out at least half of all species. Many smaller scale mass extinctions have occurred, indeed the disappearance of many animals and plants at the hands of man in prehistoric, historic and modern times will eventually show up in the fossil record as mass extinctions. Discover more about Earth's major extinction events below. Butterflies the flying Jewels: Biologists estimate that worldwide there are about 150,000 different species of butterflies and moths, in which approximately 30,000 belong to the butterfly species. The size of a few species of butterflies ranges from less than an inch in size to a wing span of about 10 inches. The smallest species are no bigger than a fingernail and the largest swallowtails are larger than the smallest birds. The world’s tiniest known species, the blue pygmy (Brephidium exilis), is found in Southern California and has a wing span of just Mumbai University, S.B.Sc. Zoology, Sem III Paper-USZO303, Year 2017-18 over half an inch. Both the world’s smallest butterflies occur in peninsular India. The largest species, the New Guineas Queen Alexandria’s bird wing (Ornithoptera Alexandrae) can measure up to twelve inches from wingtip to wingtip. The Goliath Bird wing butterfly is the second-largest butterfly in the world. The largest moth, The Atlas Moth (Attacus atlas) has a wingspan of 1 foot (30 cm). The smallest moth, the Nepticulid moth is 0.1 inch long. Destruction of its habitat is threatening this beautiful creature with extinction. Butterflies provide aesthetic appeal and are connected with all plants and crops at all stages of their life cycle. Few are aware of the crucial role the butterfly plays in pollination of a large portion of economically important crops and flowering plants, which is second only to the honeybee. They pollinate about 75 per cent of staple crops in the world and 80 per cent of all flowering plants. The economic value of pollination is about $ 200 billion. Scientific studies have proved beyond doubt that pollinators account for 12% of the value of world ide agricultural production. Beneficial Aspects of Butterflies: Butterflies are categorized as keystone species, which enable many smaller species of insects to thrive and reproduce in an ecosystem. In simple terms, it denotes that conservation of butterflies, also conserves, other species of insects. In fact, the basic health of our ecosystem is directly dependent on the number of butterfly species. Butterflies act as indicators in monitoring environmental health. Play an important role in food chains and food webs. Excellent pollinators. Bio control of weeds. Butterflies are very sensitive to pollution and have been used as bio-indicators to detect the pollution levels Facts: The fact of the matter is that most butterfly species have an average lifespan ranging from 20 to 40 days. A few species may live up to nine months Butterflies are found worldwide except on the continent of Antarctica Butterflies can only see the colours red, green and yellow Most butterfly species are dark coloured because they need to absorb heat from the surrounding environment Caterpillars spend most of their time eating leaves using strong mandibles (jaws). A caterpillar's first meal, however, is its own eggshell. A few caterpillars are meat-eaters; the larva of the carnivorous Harvester butterfly eats woolly aphids Butterflies do not have any chewing mouth parts. They are gifted with a tubular straw like appendage known as proboscis which enables them to sip nectar. Butterflies "smell" with their antennae and taste with their feet Butterflies are one of the few creatures on earth that can orient themselves both in latitude and longitude Male butterflies attract females by releasing pheromone chemicals (scent) from their abdomen Butterflies and moths are picky in choosing leaves for egg laying. Butterflies and moths are picky in choosing leaves for their diet. When folded, a butterfly's wings are usually much less colourful, providing instant camouflage from would-be predators The earliest butterfly fossils are from the early Cretaceous period, about 130 million years ago. Their development is closely linked to the evolution of flowering plants (angiosperms) Butterflies are the only insects that have scales .Butterfly scales contain pigment, which in combination with light refraction gives butterflies their colors Moth species outnumber butterfly species by 16-to-1. Mumbai University, S.B.Sc. Zoology, Sem III Paper-USZO303, Year 2017-18 Butterfly Smuggling: A global network of poachers and smugglers are wiping out threatened species of butterflies. Smugglers entice the locals and school children by paying them rupees fifty for every butterfly they catch. They are then killed, dried and used in greeting cards, wall plate hangings and for other ornamental and decorative purposes. In the international market some species of butterflies like the bird wing butterfly found on the Tiger hill of Jammu and Kashmir is sold at $2500. The yellow colour in the wings of some species is permanent and is used in gold ornaments. The most endangered species are the giant swallowtail Papilio homerus, whose velvety black and gold wings are highly prized as decorative agents. In spite of butterflies being protected by international and national laws, butterfly smuggling is rampant in India, especially from the Western Ghats. Lack of expertise in the identification of butterflies (Endeared, rare, threatened species) helps smugglers get away. Such lacuna in the system needs to be corrected with immediate effect. Believe it or not, trade in endangered species (including wildlife) is worth an estimated 15 billion dollars a year. Blue mormon:- Papilio polymnestor, which is commonly known as Blue Mormon, has been declared as the state butterfly by the Maharashtra government on June 22. Maharashtra has also become the first state to have the second largest butterfly, found in India, as the State butterfly. The decision was taken at a meeting conducted by the State Wildlife Board in Mumbai. The meeting was chaired by Finance and Planning Minister Sudhir Mungantiwar. Earlier, the State of Maharashtra had also considered Giant Squirrel as the state animal and Green Pigeon as the state bird. Here are some facts on the State butterfly of Maharashtra, Blue Mormon: It has velvet, black wings with bright blue spots It is the largest butterfly in India after the Troides minos commonly known as the Southern Birdwing It is only found in Sri Lanka, the western ghats of Maharashtra, South India and coastal belts of the country Out of the total number of butterflies in the country, only 15 percent are found in Maharashtra. To conserve butterflies in Maharashtra, Blue Mormon was declared as the state butterfly The population of Blue Mormons is not threatened. Although the Blue Mormons can be seen throughout the year, they occur more commonly in the monsoon or after it The most number of Blue Mormons are found in Sri Lanka because the country has availability of the most number of food plants The butterfly is most common in evergreen forests The pupa of this butterfly is very large in size Blue Mormons usually like to sit on the Ixora flower species.