Nov.+3,+2008

Assigned journal entry The sun is one of the many environmental pressures that drives natural selection in my eco zone. Because the sun affects the seaweed, because I noticed that as the seaweed got more closer to the shore it became greener with more nutrients, but when I went out towards the sea it became more of a brownish, green color because of it’s time in the ocean, and soaked by the sea water. I also noticed that the seaweed that was the farthest away from the shoreline it had thorns or sharp things on it and a rougher texture feeling. I think that this is because there is a more chance of fish trying to eat it because it’s closer to their environment. So by coping with the fish the seaweed grew thorn and a rougher texture so it won’t get eaten by fish. The waves and tides is another element that drives natural selection because if the tide is high and the fish goes, where it was just low tide, and in those six hours that it is in the high tide spot, the tide changes and suddenly it is low tide. So the fish has to wait for the high tide to go back so it can go back to the ocean, but if the timing isn’t right and it takes more than 6 hours then the fish is likely to die. So the fish would reproduce and make them survive with limited amount of water, until the high tide comes back. Also the waves that crashes against the rocks affect the crabs that are tanning against them. I think that the crab has a hard shell for predators but also for the pounding of the waves against their body, this is because if your protective shell isn’t strong enough for the oncoming waves then you will die from it. So this drives them to reproduce the strongest shells and the toughest crabs will be the ones reproducing. Another environmental pressure is run-off from the cliff that is right above the tide pools, and because of the heavy rains that we have been having the mud that is not secured by the grass went into the ocean and thus killing fish and other species like the algae. So this is driving natural selection because the fish who can survive this event will be the ones reproducing the fish who can be immune to the water being dirty and unclear. This also can make the algae put themselves in another spot away from a cliff or making themselves more abundance so when it does happen that there is so much of them it can survive after it is all done.

FREE journal entry: My role is to observe the crab. What I noticed about them was that there are two types of crabs, one has a black and grayish color to it with a rough texture, and another one with a brownish, white, and dark brown. So why is there two types of crabs living closely to each other? Why is one bigger than the other does it really matter? The black and grayish color had has this type of colors because it can blend in with it’s background from predator’s like the birds and us people. Their mostly black and gray because the rocks that they live on are mostly black and gray. These types are crabs are palm size and are much bigger than the full grown adult of the smaller brownish white crab. I think that the brown crab is much smaller because I only see them in the tide pools and not overlooking the cliffs like the black ones do. I also think that they have to blend in with their environment, which is sand and brown seaweed that the tide pool fish eat. Also they are smaller so they don’t stand out as much as the bigger fish. So do you think that the two crabs came from the same ancestor but then their was to much competition so one went to the tide pools and the other stayed the same? I think so because crabs are crabs and have the same body structure as one another no matter its size. But then their might be competition if they are living in the same niche so one has to cope for another so they can both survive and if they don’t cope then the strongest survives and the other dies out. Exploring at the tide pools I found a couple of crabs skeletons in the pools. I wonder what could have eaten the brownish white crabs instead of its relative the black crab? I thought that because there is more deaths of small crab then bigger crabs is because they are smaller than the others, so they can be eaten easier without a big fight. I also think that there is more than one predator. I think that there is the eel which can eat anything and the fishermen says there is a lot of them near the tide pools. Also the octopus which can eat fish and crab for dinner. And also if their not in the water then if their on land they can be eaten by birds passing by for a snack.

Photos Nov3.