Week 3 Post

 Homologous the trait which is carried by the common ancestor and passed down can be seen in many reptiles. Particularly monitors and crocodiles. Like how the beak of each bird is suited to its diet so is the mouth of reptiles.

 Both reptiles use their jaw strength to initiate in a maneuver known as the death roll. It is performed by clamping their jaws shut around the intended target and completing a number of rolls to tear of chunks for consuming. While the larger more powerful crocodile has perfected this technique in the form of its large interlocking teeth, the monitor must use this move to take down larger prey or simply stun its victim.  The difference in teeth structure is what has changed due to their hunting environment and prey. As previously stated a crocodiles large are more suited to its large prey and also helps to grip the animal as it is dragged to the water. The monitors diet consists of a wide range of items, including plants and fish so its teeth wouldn't have to be a large. The common ancestor which had the selective traits of scales, skeletal arrangement and muscle came from the amphibians and were known to eat small fish. This would suggest they would have had the same sharp teeth in order to hold on to fish.


   For the representation of the analogous trait I chose to show Crickets and Honeybees. Using crickets as feeders you witness some pretty interesting behavior, particularly when they eat. Plus I find it rather adorable. The traits in question are the development of the antennae and mouth of these two insects. A crickets antennae have evolved into long thin strands that the insect uses to warn off other males and sense females.

The mouth of a cricket, which unfortunately I couldn't get a closer image of is made for biting and chewing. Since unlike bees they are omnivores and will consume most organic matter, like plants and other weaker crickets.

 

The honeybee which has shorter antennae uses them along with "dance" and pheromones  to communicate with others in the hive. The use is more complex as is the bees social interactions. It's mouth is developed to drain nectar from.

 Rhyniognatha hirsti was the first known insect and it appeared about 400 million yaers ago. Although this insect is considered to be the first of the flying insects it also has a mandible. The trait both these species share. So it could be said that somewhere along the line of crickets was a decendent with that trait as well.