Ten important discoveries from last decade 1 By Upasana Gupta.
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Transcript of Ten important discoveries from last decade 1 By Upasana Gupta.
Ten Ten importantimportant
discoveriesdiscoveries
from from last decadelast decade
11http://pariworld.in By Upasana Guptahttp://pariworld.in By Upasana Gupta
Butterfly Supergens
2http://pariworld.in By Upasana Gupta
• The butterfly species Heliconius numata has long proved a mystery. Its population carried seven different discrete wing-patterns.
• A team of British and French biologists discovered in 2011 the presence of what they called a supergene, a cluster of eighteen genes passed down in a single unit.
Discovery: Butterfly supergenes demonstrate
unknown method of inheritance
3http://pariworld.in By Upasana Gupta
Humanzees
4http://pariworld.in By Upasana Gupta
• It’s well known that chimpanzees are humankind’s closest surviving relative.
• There are some that believe a human-chimp hybrid named Oliver survived until last year, though DNA testing has proven he was just a normal chimp that displayed human-like traits.
• David Reich explained, “That such evolutionary events have not been seen more often in animal species may simply be due to the fact that we have not been looking for them.”
Discovery: Human and chimp interbreeding
5http://pariworld.in By Upasana Gupta
Old Bat
6http://pariworld.in By Upasana Gupta
• Bats are the second largest order of mammals, accounting for a fifth of all mammalian species.
• A pair of fossils discovered in Wyoming in 2003, part of a new species dubbed Onychonycteris finneyi, has many odd features.
• Joining the dozens and dozens of other transitional fossils completely invisible to creationists, the fifty-two million year old specimen ends decades of speculation amongst scientists.
Discovery: Decades-old bat mystery finally solved by
intriguing fossil
7http://pariworld.in By Upasana Gupta
Tiktaalik8http://pariworld.in By Upasana Gupta
• One of the most profound transitions in the history of life was the move from water to land. Tetrapod is the name given to the first creatures to leave the water and the name means four limbs .
• The first tetrapods are the ancestors to all living reptiles, amphibians, birds and mammals. Scientists have long understood that tetrapods evolved from lobe-finned fish, themost famous example of which is probably coelacanth
• Tikaalik was the first fossil that is still a fish but displayed the beginnings of digits, wrists, elbows and shoulders.
Discovery: Tiktaalik provides missing link between fish and land animals
9http://pariworld.in By Upasana Gupta
Lice10http://pariworld.in By Upasana Gupta
• Lice, which have been irritating human scalps for tens of thousands of years, offer a unique method to exploit this. Lice are specialists with claws adapted to their host, so when their particular meal of choice evolves into a new species, the lice follow suit.
• DNA testing of lice was done by a (probably really itchy) team of researchers at London’s Natural History Museum, offering implications for our knowledge of the evolution of birds and mammals
Discovery: Lice offer a new window into the history of
mammals
11http://pariworld.in By Upasana Gupta
Giant Amoeba
12http://pariworld.in By Upasana Gupta
• One of the earliest fundamental traits to evolve in the animal kingdom is that of bilateralism.
• If you divide a human in two from top to bottom through the middle you will have, for the most part, the same things on both sides.
• The creation of these particular tracks by creatures moving in a straight line was thought only possible by creatures with two halves.
Discovery: Giant amoeba casts doubt on when
symmetrical life originated
13http://pariworld.in By Upasana Gupta
Neanderthal Genome Project14http://pariworld.in By Upasana Gupta
• Neanderthals are the species that was almost us.
• In 2010 a team from Germany’s Max Planck institute published a draft sequence of the Neanderthal genome less then a decade after the mapping of the human genome was completed.
Discovery: The Neanderthal genome project suggests we’re
related
15http://pariworld.in By Upasana Gupta
Lucy’s Baby16http://pariworld.in By Upasana Gupta
• The most famous early human ancestor is probably Lucy, the 3.2 million year old skeleton found in 1974.
• Lucy became synonymous with the birth of humanity.
• Being a child skeleton makes it extremely rare. It is also more complete than Lucy.
• The child, who was still at nursing age, will add greatly to our knowledge of human ancestry but it’s hard not to be touched by the descriptions of tiny fingers and a knee cap no bigger than a dried pea.
Discovery: Lucy’s Baby steals Lucy’s thunder
17http://pariworld.in By Upasana Gupta
Oldest Ancestor18http://pariworld.in By Upasana Gupta
• The fossil that stole Lucy’s crown as the oldest known probably human ancestor in 2009. Ardi was a 110 lb (50 kg) small-brained female and she predates Lucy by more than a million years.
• Ardi was actually found in 1994 but it wasn’t until 2009, after a decade and a half of painstaking analysis, that the implications became known.
• Ardi casts a definitive blow to the old idea. She shows an unexpected mix of traits both advanced and primitive, unlike chimps or gorillas.
Discovery: Ardi is oldest human ancestor ever found
19http://pariworld.in By Upasana Gupta
Junk DNA
20http://pariworld.in By Upasana Gupta
• When the human genome project’s first draft was presented in 2000, ninety-seven percent of the 3.2 billion bases in the sequence were without apparent function.
• The primary function of DNA is to provide the designs for proteins, information which is stored in genes, but these constitute just three percent of a DNA strand.
• scientists have identified a portion of noncoding DNA that is fundamental to the development of heart cells, whilst other scientists have found mutations in noncoding DNA that appear to be a key cause of skin cancer.
Discovery: Junk DNA isn’t junk after all
21http://pariworld.in By Upasana Gupta
22http://pariworld.in By Upasana Gupta