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Monday, 11 June 2018
Origin and evolution of life..additional information 3
Evolutionary biology. T
he branch of Biology that involves the study of living system as they changed through time is known as evolutionary biology.
Study of universe or cosmos is called COSMOLOGY
-, study of universe, its nature, origin and history.
- study of possible life outside the earth.
- evolution of universe. the planets and stars change in between their birth and death.
The Stages of Cosmic Evolution by Eric Chaisson
- it is considered that it was an early single celled common ancestor of archaebacteria, eubacteria and eukaryotes. it indicates that there is no present day bacterial type regarded as an ancestor of eukaryotes.
progenote life tree
presumably originated ancient ocean in
the first organism were heterotrophic and anaerobic containing nucleoproteins.
A petrified tree is really a tree that has been turned into stone.
pliocene is the epoch of mammals.
ordovician period is also called "age of giant molluscs".
mesozoic Era is also called "age of reptiles".
coenozoic era is also called "age of mammals, bird, fishes, insects and angiosperms.
was invented by
sir Richard owen
more than a century ago to designate certain large Fossil reptiles.
were mammal- like that gave rise to mammals. they had a single temporal fossa on the lateral side of Skull and heterodont teeth.All synapsed reptiles are extinct.
when organism involved from a common ancestor it is called monophyletic origin. vertebrates evolved from a common ancestor.
it is a living Fossil which watch taken off from the coast of South Africa on December 22, 1938 by some fishermen. fisherman could not identify it's so they brough the specimen to miss Courtenary latimer curator of the local museum. when she failed to identify it, and it sketch to
Professor .J.L.B. Smith
, an eminent ichthyologist of Rhodes University college at Grahams town. he recognised is surviving member of crossopterygii (subclass of class osteichthyes) and named it latimeria chalumnii, after the discoverer and locality. its Discovery is of special interest because it is believed that crossopterygains (fleshy finned fish) were the ancestors of the first amphibians. latimeria is believed to be the oldest amongest living fishes.
(extinct reptile) is a connecting link between amphibia and reptilia.
(extinct reptile) is a connecting link between reptiles and mammals.
in 1863 A.R.Wallace Dhruv and dividing line between the Oriental and Australian region. this line is known as Wallace line. this line Run between Philippines and Moluccas in the north between borneo and celebes Southwest and between Bali and lombok South wards.
some year after weber drew an imaginary line on the map between the Oriental and Australian regions. it was considered to divide the fauna of two regions better than Wallace's line. the weber's line is further East then Wallace's line. separates Moluccas from celebes and kei Iceland from Timor.
Alpheus S. Packard jr
(1839- 1905) was the first to use the
- (1848- 94) coined the term "neo- darwinism" as well as the word
. it States that Irreversible. this law was proposed by
. it States that there is a tendency for animals to increase in size during the long course of evolution.
it states that warm blooded animals Become larger in the Northern and colder parts of their range.
. it States,animals that live in in very cold climates, their extremities such as ears, tails,etc. become progressively smaller.
1934 or the competitive exclusion principle (Hardin 1960) it States that two species having the same ecological requirement cannot continue to occupy indefinitely the same habitat.
. it states that among warm blooded animals those living in warm and moisture climates develop more melanin pigment (darker then animals in cold, dry climates) whereas from , in dry,hot climates have more yellow and red pigment.
. it states that fishes inhibiting water of low temperatures tend to have more vertebrae than those of warmer waters. it has been observed that cold water forms of many species are frequently larger than the individuals from warmer waters.
The sum total of all genes in breeding population is called
. in seth wright's farm in Massachusetts, America, a normal sheep gave birth Ram( male sheep) with very short and curved legs in 1791. by artificial breeding from this ram seth wright raised are different sheep called ancon sheep ( very short legs sheep). after several generations, this character suddenly disappeared.formation and disappearance of ancon sheep is good example of mutations (discontinuous variations).
Main theoris proposed by Charles Darwin are (i) N
atural selection theory
Sexual selection theory
rtificial selection theory
Theory of pangenesis.
it is a kind of adaptation. the term mimicry was introduced introduce in biology by Bates 1862. it is defined as "the resemblance of one organism to another objects or to any natural object for the purpose of concealment, protection or for some other advantage. the organism which exhibit mimicry is called a mimic. ther organism or object which is mimicked or imitated is called a
. it is a form of mimicry in which an edible species resembles an inedible one.
. when two or more inedible or unpalatable species resemble each other the mimicry is termed mullerian mimicry.
Both batesian and mullerian mimicries are two forms of
. a living fossils is a living animal of ancient origin with many primitive characters .A living fossil has been living as such from that time of origin without many changes. the example of living fossils are (i) peripatus- Phylum Arthropoda(ii) limulus - Phylum Arthropoda(iii) c (iv) latimeria - Bony fish (v) sphenodon- class reptilia and (vi) egg laying mammals.
peripatus- Phylum Arthropoda
limulus - Phylum Arthropoda
neopilina -phylum mollusca
latimeria - Bony fish
sphenodon- class reptilia
egg laying mammals.
June 11, 2018
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Origin and evolution of life..additional information 3