"My Inner Fish"

One of the main themes in the two episodes "Your Inner Fish" and "Your Inner Reptile" is that humans and fish have a shared ancestry, and humans and reptiles are actually closely related. There is a lot of concrete evidence in fossils and embryos to support this.

In the initial stages, a human embryo and and fish embryo look very similar because of the common Hox genes, which suggest common ancestry. Other evidence for common ancestry includes some structures that humans and fish both have today: bony skeletons, backbones and skulls, and shared basic brain anatomy.
The Sonic Hedgehog gene sends out the organizing signal; it tells cells to do different things, and creates the array of digits on the hand. Hair, which is a defining characteristic of mammals today, may have first evolved in our small mammalian ancestors as a sensory organ or a tool to help keep warm.

Another example of humans' relation to reptiles is their hearing anatomy. Mammals have an acute sense of hearing because they have 3 bones in their middle ear which form a lever system, while reptiles only have 1 bone in their middle ear. Scientists think that two jaw bones in reptiles got smaller, moved further up the jaw, and evolved to have a new purpose in the ear in mammals.

Human and fish embryos look very similar initially because of Hox genes, indicating a common ancestry

20 time update: Surveying

During the past couple weeks, I have finished creating my questionnaire that I am using to determine whether people are at risk for diabetes and heart disease. I have also interviewed 3 people using this questionnaire, and I think that it is proving reasonably effective.

My questionnaire originally contained quite specific numbers to determine whether a person was at risk for diabetes or heart disease. However, as I did my first interview, I realized that the majority of people don't know their exact test results, and at most they will remember whether it was in the low, normal, or high range. I shifted my questionnaire slightly to measure people's awareness of their own risk factors. I also used their answers of results being in the low, normal, or high range to determine their level of risk.

My next steps are to continue giving the questionnaire to more people; the more people I include in my study, the more accurate it will be.

Invertebrate of Your Choice: Jellyfish

Jellyfish are invertebrates, and belong to the phylum Cnidaria. They are the oldest existing animals that have specialized tissue. Jellyfish are medusas (non-polyps). They are part of the scyphozoans class of Cnidaria. Jellyfish are found in every ocean, and are about 500 to 700 million years old. Jellyfish are the oldest animal to have multiple organs. They cannot see, but some do have ocelli, which allows them to detect light. Jellyfish come in a very wide variety of sizes, which can range from 1 mm in height to about 2 meters in height. They don't have a central nervous system, a digestive system, a respiratory or a circulatory system. They obtain their oxygen instead by diffusion through their skin.

Source: Wikipedia

Moon jellyfish