Tuesday 14 September 2010

science-

e v o l u t i o n.

adaptation&
is the change in the inherited traits of a population of organisms through successive generations.[3] This change results from interactions between processes which introduce variation into a population, and other processes which remove it. As a result, variants with particular traits become more, or less, common. A trait is a particular characteristic, anatomical, biochemical or behavioural, that is the result of gene–environment interaction.


I'm fascinated with all aspects of science. I can't get over how simple yet complex evolution is, it is simply keeping what is good and what works along the line, but how we manage to evolve, is what is unbelievable.

EVOLUTIONARY BIOLOGY was introduced through the publication of Darwin's book 'On the Origin of Species' in 1859.

GOOD:
evolution is inheritance of traits, these are controlled by genes,




DEEP SEA CREATURES

They are different. They are interesting. They are good.


I went to an exhibition at the natural history museum over the summer holidays, it was all about deep sea creatures :



I am finding it quite hard to justify why deep sea creatures are 'good', only in the sense that I just find them so weird, and therefore so interesting to research.


I can consider the creatures themselves as 'good' due to their amazing survival instincts when up against extremely harsh conditions:
-hundreds of atmospheres of pressure -small amounts of oxygen -very little food -no sunlight -constant, extreme cold

If we lived there we wouldn't last more than a second.

Barometric pressure

These animals have evolved to survive the extreme pressure of the sub-photic zones. The pressure increases by about one atmosphere every ten meters. To cope with the pressure, many fish are rather small, usually not exceeding 25 cm in length. Also, scientists have discovered that the deeper these creatures live, the more gelatinous their flesh and more minimal their skeletal structure. These creatures have also eliminated all excess cavities that would collapse under the pressure, such as swim bladders[1].

Lack of light

The lack of light requires creatures to have special adaptations to find food, avoid predators, and find mates. Most animals have very large eyes with retinas constructed only of cones, which increases sensitivity. Many animals have also developed large feelers to replace peripheral vision. To be able to reproduce, many of these fish have evolved to be hermaphroditic, eliminating the need to find a mate. Many creatures have also developed very strong senses of smell to detect the chemicals released by mates.



To deal with lack of light, they have developed through evolution, amazing sense of smell, their eyes have large retinas and are constructed only from cones (this increases sensitivity), majority also have large feelers to.. feel around..

Lack of Resources

At this depth, there is not enough light for photosynthesis to occur and not enough oxygen to support a fish living at higher levels. To survive, these creatures have much slower metabolisms and therefore can survive using little oxygen. They can also go months without food. Most food comes from either organic material that falls from above or from eating other creatures that have derived their food through the process of chemosynthesis (the process of changing chemical energy into food energy). Because of the sparse distributions of creatures, there is always at least some oxygen and food. Also, instead of using energy to search for food, these creatures use particular adaptations to ambush prey.

At the depth these creatures are at, there is not enough light for photosynthesis to occur, these fish have adapted to survive with little oxygen due to lower metabolisms. They can also go months without food. That is where they find there oxygen.





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