7 Animals That Are Evolving Right Before Our Eyes

reply to post by LikeDuhObviously

Lets put it this way, there is a growing cohort of people found to be immune to the HIV virus. And its just a happy accident. Or to use another apocalyptic scenario more realistic than a global flood, World War III breaks out, a nuclear holocaust, and 6.6 billion people die from the radiation. However there would probably be a tiny fraction of people that survive, that are resistant to intense amounts of radiation. Another happy accident. Obviously the survivors reproduce differentially and in another million years or so the population grows to about 5 billion.

reply to post by LikeDuhObviously


Except for these guys. They're called tardigrades or "water bears".

Tardigrades are polyextremophiles; scientists have reported their existence in hot springs, on top of the Himalayas, under layers of solid ice and in ocean sediments. Many species can be found in a milder environment like lakes, ponds and meadows, while others can be found in stone walls and roofs. Tardigrades are most common in moist environments, but can stay active wherever they can retain at least some moisture.

Tardigrades are one of the few groups of species that are capable of reversibly suspending their metabolism and going into a state of cryptobiosis. Several species regularly survive in a dehydrated state for nearly ten years. Depending on the environment they may enter this state via anhydrobiosis, cryobiosis, osmobiosis or anoxybiosis. While in this state their metabolism lowers to less than 0.01% of normal and their water content can drop to 1% of normal. Their ability to remain desiccated for such a long period is largely dependent on the high levels of the non-reducing sugar, trehalose, which protects their membranes. In this cryptobiotic state the tardigrade is known as a tun.[16]

Tardigrades have been known to withstand the following extremes while in this state:
Temperature – tardigrades can survive being heated for a few minutes to 151 °C (424 K),[citation needed] or being chilled for days at -200 °C (73 K),[citation needed] or for a few minutes at -272 °C (~1 degree above absolute zero).[9]
Pressure – they can withstand the extremely low pressure of a vacuum and also very high pressures, more than 1,200 times atmospheric pressure. Tardigrades can survive the vacuum of open space and solar radiation combined for at least 10 days.[9] They can also withstand pressure of 6,000 atmospheres, which is nearly six times the pressure of water in the deepest ocean trench.[10]
Dehydration – tardigrades have been shown to survive nearly 10 years in a dry state.[17] When encountered by extremely low temperatures, their body composition goes from 85% water to only 3%. As water expands upon freezing, dehydration ensures the tardigrades do not get ripped apart by the freezing ice (as waterless tissues cannot freeze).[18]
Radiation – tardigrades can withstand median lethal doses of 5,000 Gy (of gamma-rays) and 6,200 Gy (of heavy ions) in hydrated animals (5 to 10 Gy could be fatal to a human).[19] The only explanation thus far for this ability is that their lowered water state provides fewer reactants for the ionizing radiation.[citation needed] In September 2007, a space launch (Foton-M3) showed that tardigrades can survive the extreme environment of outer space for 10 days. After being rehydrated back on Earth, over 68% of the subjects protected from high-energy UV radiation survived and many of these produced viable embryos, and a handful survived full exposure to solar radiation.[9]

People act as if evolution is only supposed to produce indestructible things...even though it sometimes gets damn close to doing so.

It can survive greater pressure than you find at the bottom of the deepest ocean...I can think of no adjective or adverb/adjective combo appropriate for how in awe I am.

reply to post by uva3021


I admit, it was a gross oversimplification.

There is no way for an organism to adapt outside of genetic characteristics already in place within its own lifetime aside from modifications to behavior.

Some genetic characteristics include an increase in body fat when introduced to a colder climate.

Originally posted by uva3021
reply to post by LikeDuhObviously

 

Lets put it this way, there is a growing cohort of people found to be immune to the HIV virus. And its just a happy accident.

No, no accident there.
HIV resistant people have been around longer then disease has been around.
Disease and illnesses suffered by your ancestors and your ethnicity play roles in this.

As in your genetic history. Not a good example of something adapting over 1 generation.

I think you are trying to use the immune system as an example. Sadly HIV kicks the # out of our immune systems.

As HIV accumulates in the blood, specific immune cells that target viruses - called CD8 - begin to over-produce a receptor molecule called Programmed Death-1. As this PD-1 builds up on the surface of the CD8 cells, the immune cells became weaker and produced fewer virus-killing chemicals, such as cytokines.

www.newscientist.com...

This is a reason why it is so bad, Add it evolves "quicker" then us and you got yourself one nasty ass disease.

Illnesses that our immune system can deal do not help your case. Our immune system is well evolved over a very long time.

Evolution is always about "breeding" in a very sense manner.

See... it`s always the ones that survive long enough to F$@! more, that get their genes going by after them.

Now...selection as in "selective breeding" implies will / conscience?


Peace

reply to post by LikeDuhObviously

Slightly misunderstanding my point. Of course the immune system for the fortunate few was already equipped with the means to resist HIV. However, unforeseen selection pressures are constantly exerted that filter out those who don't have the immune systems to resist HIV. For the medicinal field, where the problem arises is searching for a cure rather than letting the HIV virus reach its optimal virulence. As of yet, a dead host is a bad host, and from the HIV virus' point of view, its too virulent. Now, countered with some sort of chemical attack, the virus will only become more virulent. Left alone, perhaps thousands of years from now the HIV virus will merely be analogous to a seasonal cold, in this case a venereal pest.

I went on a little tangent, but the initial point is we can't anticipate how our body responds to unforeseen selection pressures.

Imagine 100,000 years from now, cane toads evolve into organisms that are 7 feet tall, super athletic, extremely intelligent, and tongues that can break a man in half with a snap. They force all humans to jump off of a cliff, to their impending death, wiping out the entire species. Jumping off of a cliff without hang glider or other flight-aid is an unforeseen selection pressure. Perhaps, because our anatomy has yet to be tested with how it responds to cliff jumping, a tiny fraction of humans will respond favorably to cliff jumping. Their arms will spread out, their sides split open and a type of membrane stretches from each side to the base of the hand, sort of like a flying squirrel. Now this is unlikely, but the point is, unforeseen selection pressures may betray traits that always existed, perhaps traits that are vestigial, though never had a reason for being expressed.

I don't get how the Grolar Bear is speciation. It said two species were breeding, that would make them one species. Hmm.

reply to post by uva3021

People who are resistant to HIV lack the receptors from their cell membranes that the virus uses to get into the cell.

Also, the dogs learning the subway system is not evolution. This article is definitely taking a facetious approach to evolution.

reply to post by addygrace


How is that not evolution? Dogs with greater navigational abilities are surviving, those which don't have them are dying off. That's natural selection as clear as day.

reply to post by addygrace


Interfertility can exist within a genus, though the gene transfer rate between the gene pools would be quite low...of course, in this case it seems that those polar bears who can breed with grizzlies and produce fertile offspring are. Hybridization is a means to allele frequency change within a gene pool.