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[ASK] Asal-usul virus??

Dimulai oleh blacklist_boy, Januari 24, 2010, 07:38:13 AM

« sebelumnya - berikutnya »

0 Anggota dan 1 Pengunjung sedang melihat topik ini.

Astrawinata G

nah itu dia Mas :( kagak tau juga....memang masih kontroversi y Mas?
Best Regards,


Astrawinata G

Hendy wijaya, MD

Tindakan mencegah cervical cancer dengan cara menangkal infeksi HPV dengan vaksinasi merupakan implikasi yang logis dari fakta bahwa HPV menyebabkan cervical cancer. Itu bukan hal yang kontroversi. Yang menjadi masalah belakangan adalah masalah teknis setelah vaksinasinya, bagaimana kita tahu kalau orang yang telah kita vaksin cukup imun terhadap infeksi HPV?apakah orang tersebut perlu divaksin ulang atau sudah cukup?ga tau..
Tantum valet auctoritas, quantum valet argumentatio

Astrawinata G

banyak penelitian yang mesti dilakukan untuk menetapkan peru tidaknya booster vaksin HPV Mas :) mari menunggu
Best Regards,


Astrawinata G

Hendy wijaya, MD

Betul bung astra..setiap fakta baru selalu diboncengi pertanyaan baru.. mari kita tunggu :)
Tantum valet auctoritas, quantum valet argumentatio

semut-ireng

Where did viruses come from?

Ed Rybicki, a virologist at the University of Cape Town in South Africa, answers:

Tracing the origins of viruses is difficult because they don't leave fossils and because of the tricks they use to make copies of themselves within the cells they've invaded. Some viruses even have the ability to stitch their own genes into those of the cells they infect, which means studying their ancestry requires untangling it from the history of their hosts and other organisms. What makes the process even more complicated is that viruses don't just infect humans; they can infect basically any organism—from bacteria to horses; seaweed to people.

[pranala luar disembunyikan, sila masuk atau daftar.]

semut-ireng

Keluarga Virus Tertentu Sudah Ada Puluhan Juta Tahun yang Lalu

"Hingga saat ini, usia perkiraan untuk semua virus selain retrovirus berada dalam ribuan tahun, dan tak seorang pun berharap mampu melacak virus luar itu berdasarkan kerangka waktu karena tingginya tingkat mutasi virus yang paling umum," ujar Anna Marie Skalka dari Fox Chase. "Kami menunjukkan bahwa beberapa keluarga virus telah ada selama puluhan juta tahun, dan hampir tidak berubah selama kerangka waktu."

[pranala luar disembunyikan, sila masuk atau daftar.]

Fatra

kalau virus itu makhluk hidup yang sederhana, berarti awal mula kehidupan di dunia ini virus,

Pi-One

Kutip dari: Fatra pada Desember 24, 2014, 12:32:54 PM
kalau virus itu makhluk hidup yang sederhana, berarti awal mula kehidupan di dunia ini virus,
Jika maksudnya virus adalah moyang semua makhluk hidup, kemungkinan tidak..
Virus memerlukan inang, terus inangnya dari mana?

milmi

Ini ada penjelasan yg cukup menarik:
KutipTracing the origins of viruses is difficult because they don't leave fossils and because of the tricks they use to make copies of themselves within the cells they've invaded. Some viruses even have the ability to stitch their own genes into those of the cells they infect, which means studying their ancestry requires untangling it from the history of their hosts and other organisms. What makes the process even more complicated is that viruses don't just infect humans; they can infect basically any organism—from bacteria to horses; seaweed to people.

Still, scientists have been able to piece together some viral histories, based on the fact that the genes of many viruses—such as those that cause herpes and mono—seem to share some properties with cells' own genes. This could suggest that they started as big bits of cellular DNA and then became independent—or that these viruses came along very early in evolution, and some of their DNA stuck around in cells' genomes. The fact that some viruses that infect humans share structural features with viruses that infect bacteria could mean that all of these viruses have a common origin, dating back several billion years. This highlights another problem with tracing virus origins: most modern viruses seem to be a patchwork of bits that come from different sources—a sort of "mix and match" approach to building an organism.


The fact that viruses like the deadly Ebola and Marburg viruses, as well as the distantly related viruses that cause measles and rabies, are only found in a limited number of species suggests that those viruses are relatively new—after all, those organisms came along somewhat recently in evolutionary time. Many of these "new" viruses likely originated in insects many million years ago and at some point in evolution developed the ability to infect other species—probably as insects interacted with or fed from them.


HIV, which is thought to have first emerged in humans in the 1930s, is another kind of virus, known as a retrovirus. These simple viruses are akin to elements found in normal cells that have the ability to copy and insert themselves throughout the genome. There are a number of viruses that have a similar way of copying themselves—a process that reverses the normal flow of information in cells, which is where the term "retro" comes from—and their central machinery for replication may be a bridge from the original life-forms on this planet to what we know as life today. In fact, we carry among our genes many "fossilized" retroviruses—left over from the infection of distant ancestors—which can help us trace our evolution as a species.


Then there are the viruses whose genomes are so large that scientists can't quite figure out what part of the cell they would have come from. Take, for instance, the largest-ever virus so far discovered, mimivirus: its genome is some 50 times larger than that of HIV and is larger than that of some bacteria. Some of the largest known viruses infect simple organisms such as amoebas and simple marine algae. This indicates that they may have an ancient origin, possibly as parasitic life-forms that then adapted to the "virus lifestyle." In fact, viruses may be responsible for significant episodes of evolutionary change, especially in more complex types of organisms.


At the end of the day, however, despite all of their common features and unique abilities to copy and spread their genomes, the origins of most viruses may remain forever obscure.

Sumber: [pranala luar disembunyikan, sila masuk atau daftar.]

MuhammadRyan

Virus gk bisa dideteksi lajur evolusinya...

Mengetahui Virus bkan termasuk mahkluk hidup yg biasa kita temukan di rantai evolusi (Bakteria, Archaebacteria, Eukarya) yg puny sistem metabolisme...

Aku yakin, Virus gk punya nenek moyang yg sama dgn kita (Protobion)...

Virus... smpe sekarang, misterius. Tujuan hidupnya cmn menginfeksi dan berkembang biak...

Matur nuwun :D
"Saat gerah keterlaluan"
"MATAHARI ADA DUA!!!"
"Liat ABG Kumisan..."
"Asli gak tahan, pake ini itu gak mempaaaan!"

embrio11s

Kutip dari: MuhammadRyan pada Juni 07, 2015, 08:23:08 AM
Virus gk bisa dideteksi lajur evolusinya...
Mengetahui Virus bkan termasuk mahkluk hidup yg biasa kita temukan di rantai evolusi (Bakteria, Archaebacteria, Eukarya) yg puny sistem metabolisme...
Aku yakin, Virus gk punya nenek moyang yg sama dgn kita (Protobion)...
Virus... smpe sekarang, misterius. Tujuan hidupnya cmn menginfeksi dan berkembang biak...
Matur nuwun :D

Dulu, waktu kakek saya masih berjuang melawan penjajahan Belanda, teknologi DNA belum seberkembang sekarang. Jadi, untuk mengetahui hubungan kekerabatan dan jalur evolusi makhuk hidup, saat itu masih banyak menggunakan pendekatan morfologi. Setiap ciri antar individu dikarakterisasi, dicari persamaan dan perbedaannya, kemudian dianalisis kladistiknya menggunakan konsep plesiomorfi, apomorfi, dan prinsip parsimoni. Dari kladogram yang dibuat, bisa diketahui hubungan kekerabatan dan evolusinya.
Kalau sekarang, teknik molekuler sudah sangat berkembang. Hubungan kekerabatan dan evolusi bisa diketahui dengan metode yang sama, namun data persamaan dan perbedaan yang dianalisis bisa menggunakan sekuen DNA. Selama suatu "benda" punya DNA untuk diperbandingkan dengan "benda lain", maka hubungan kekerabatan dan evolusi bisa ditentukan, termasuk virus.