DARWIN RESEARCH LABORATORY

This theory tells about the correlation between metabolic gradient and evolution. I want to say that I am inspired by the metabolic gradient theory of C. M. Child, which simply states that metabolic rate is higher in the head region and gradually decreases towards the tail region . Above theory motivates my thinking and I apply this theory to the evolutionary processes and found that this theory is applied with some exceptions. In simple words, this theory states that evolutionary agents work faster in the head region and gradually become slower in the tail region because of metabolic gradient. This may be because of the nervous system which is well developed in the head region and gradually decreases towards the tail region. Nervous system develops earlier than most body parts so nerve growth factors secreted by them may be responsible for that. That’s why this theory applied does not apply to organs which developed earlier than the nervous system. What about the animal...

Mammals are vertebrates with hair and mammary glands, which produce milk for nursing their young. Mammals may be divided into two groups Prototheria and Theria. Prototherian are oviparous and Therian are viviparous. Theria is a subclass of mammals. It includes Eutherians (placental mammals) and metatherians (marsupial mammals). Mammals have a wide variety of skin glands, but all seem to be variations of two major glands, Sudoriferous (sweat) and Sebaceous (oil) glands. Mammary glands appear to be modified sebaceous glands. Mammary glands arise in both sexes from a pair of ribbons of ectoderm called milk lines which extend along the ventro lateral body wall of the fetus from the axilla to the groin. A teat  is the projection from the breast or dug or udder or mammary glands of mammals from which milk is ejected for the purpose of nursing young. The number and positioning of mammary glands and teats varies widely among mammals. The ...

Any species in which organism interacts with another member of its own species is called social. Eusociality is more complex and defined by the presence of three basic attributes viz . cooperative brood care, reproductive division of labor and overlap of generations. Species that lacks one or more these three basic attributes are called presocial. Presocial can further subdivide in to subsocial and parasocial. Subsociality refers to the social behavior between parents and offspring and parasociality refers to the social behavior among members of same generation. Besides these three basic attributes, sometimes other characteristics like communal nest construction and living, altruism, swarming, territorial defense, trophallaxis, corpse management, group decision making, group communication etc may also present. The division of labor creates behavioral groups called castes. Eusocial species with a sterile caste is sometimes called hypersocial. Advanced eusocial organisms may also show...

In mythology horns are associated with demos but in reality they are associated with herbivory. Ruminants are artiodactyls mammals. They are herbivores and possess special process of rechewing the cud called rumination. Darwin was first to suggest that horns evolved for sexual selection. Cranial appendages have different shape and size according to species viz . straight, spiral, curved, bent, flat, flipped, short, wide, long etc . Ruminant mammals use cranial appendages mostly for defense and sexual attraction. Out of six extant families of ruminants, four families possess these cranial appendages viz . Cervidae, Bovidae, Antilocapridae and Girrafidae. Tragulidae and Moschidae do not possess it. Cranial appendages of Cervidae is called antlers, cranial appendages of Bovidae is called horns, cranial appendages of Girrafidae is called ossicones and cranial appendages of Antilocapridae is called pronghorns. All cranial appendages are internally projections of frontal bones of skull a...

Stripes and spots on animal body always intrigue mankind. We also sometimes cross zebra crossing at road. As a human we know the importance of color pattern in the races of the world. Different tribes living in Africa, North America and Australia use striped body painting to deter biting flies. There are hundreds of animals with different and distinct pattern of stripes  viz . Tiger, Chipmunks, Coral Snake, Honey Bee, Monarch Butterfly, Butterfly fish, Tasmanian devil, Okapi, Tiger salamander, Coral fish, Clownfish  etc . Most interesting and unique case is of Zebra stripes. Some questions always puzzled us like what is cause and function of these stripes? Do they have any significance? What selective pressure causes their evolution? This stripe riddle has puzzled mankind for over a century. Even Charles Darwin and Alfred Russell Wallace were unable to give plausible explanation for this. Dark color of skin or fur contains melanin which protects against ultraviolet radiation...

We all are familiar with YouTube. We cannot watch all YouTube Videos in our lifetime. YouTube is an American video sharing platform founded in February 2005 currently owned by Google. YouTube allows users to upload, view, share, like and download videos. It is almost free and open access. With the ease of internet access its use is continuously increasing specially in metropolitan areas. Previously its use was limited for video sharing and entertainment but after introduction of smart phones and cheap internet services, it became more popular and its use became multidisciplinary with broad scope. Recently in few years its impact on higher education became more prominent and nowadays it became important tool of learning in higher education. Other contender platforms such as Vimeo, Metacafe, Dailymotion, Flickr, Vevo, Twitch, D tube, IGTV, 9gAGTV, Facebook watch  etc.  are also available (Twitgoo.com) but their impact and role in higher education is negligible as compared to Y...

Concept of evolution always amazes mankind. The term evolution literally means any change in organism, its body parts and its phenotype from its previous state. If we biologically define evolution, it is a change in the heritable traits (adaptations) over successive generation. There are three main theories which explain evolution. Most famous theory is of Darwin. Lamarck quoted evolution as “inheritance of acquired characters”. He believed that organisms traits that acquires and changes during their lifetime can also pass over to successive generation (Lamarck, 1809). It means environment can drive slow mutation. Later Darwin quoted evolution as “descent with modification”. He believed that environment is not static and dynamic so to cope with this changing environment, organism has to change their adaptations (traits) for survival and reproduction (Darwin, 1859). Darwin believed natural selection is the mechanism of evolution. Hugo de Vries define evolution as “heritable change in ...