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Evolution 'favours bigger sea creatures'

The journar Science publiques a new discovery: the animals in the oceans have been getting bigger since the Cambrian period and it is not by chance. 

In the past 542 milion yeras the marine animals have gone up by a factor of 150. There is a rule of increasing body and it is not made by chance, it has a sense in the evolution. 

Measured by volume, today smallest animal in the sea is less 10 times smaller than his Cambrian counterpart. It's is a musclues. But at the same time the blue whale is more than 100.000 times bigger than his  Cambrian counterpart. Cope is the idea that natural selection has made that animals increase gradually their size. 

The 19th-Century palontologists already notice that the ancient ancestors used to be smaller. However it is not the same across the animal kingdom. For example most dinosaurs were bigger than their evolutions in the actually like the birds who need fligth so they can't be very big. 

Dr Noel Heim, from Stanford University in California, has had working 50 high school students over the last five years to scour the scientific record for body size data. Finally the team could have information about over 60% of all animal genere that ever have lived. The conclusion was that  there is a tendency towards increasing size. 

But they can comprove that the families of animals that were larger diversifying and expanding more times. So the oceans gradually built up a great variety of animals increasingly large. 

To know if all that is the evolution or is only chance the team put all the information in a computer and thanks to a programe they colud see how all species have colud develop. Each species could die out, stay the same, or get bigger or smaller. Scientifics programed the computer some times to let animals develop without any requirement and some times they put requiremets like as more big an animal is the less possibilityes he has to live. 

The reaseachers cannot be sure but they think that latge species took advantage of be able to burrow better, eat larger prey or rum faster. 

Dr Michael Berenbrink, an evolutionary physiologist at the University of Liverpool, thinks that the team have grat data set but the information should be interpreted carefully because the size is not only a proces of evolution. There are some important facts in the story of the evolution that makes increased the large of animals. For example one is when mamels returned to the water. 

Dr Heim are agree with that but he also thinks that the huge diversity of other lifes, like the fish, mollusc or invertebrates, continued the trajectory of expanding size. 

 I have choose this article because, how I said in the last new, I like to know about differents things and biology is one of my favorites. I think that I have talk more times about the sea and the true is that I love the sea and all that have relation with it. 

I'm interested in oceans because I think that they are an important part of the Earth life, although some don't know yet. The oceans move a lot of water and they be home to a lot of different species.

Apart to be very important in the world, I think that what interested me more of the oceans are the things that we already can discover there. The oceans are already a mystery for us in some aspects and the pity is that we are killing them before discover.