Drafts

Migratory patterns are intrinsic behaviors that are controlled by photoperiods, gonad cycles and hormones as well as proximate factor such as weather and food availability trigger day-to-day actions while migrating. These behaviors are typically recurrent, however,  they also require correct conditions or access to resources to remain viable.  Given the extraordinarily long distances that some species travel; monitoring their movement and accumulating data on this has been challenging. Modern technological advances in doppler radar technology has allowed for more detailed tracking of large migratory patterns of several species. With information regarding their altitude, speed and direction, experts can made educated assumptions or even confidently identify which species they are monitoring.

The first experiment, done in the 1950s by the German, Gustav Kramer,  suggested that birds use the sun for directional positioning. The birds were housed in a circular cage that allowed them to see the sun. During migrating season,  they would face Northeast at all times, as if they were preparing for migration. However, on cloudy days they would not have any inclination towards any direction. Similar results were also observed in pigeons that were exposed to varied climates and asked to return to their homes. The birds in clear weather excelled where as the subjects in poorer conditions were unsuccessful or less efficient.  Of note, these birds were observed correcting for the sun’s position,  a technique that was noted to be similar to telling time.  This phenenomenon, dubbed the sun-arc hypothesis, was supported by an experiment where a lightbulb was substituted for the sun and the birds naturally corrected in anticipation of this pseudo-sun setting.

    In Spring 2018, as part of the Writing in Biology course at the University for Massachusetts, Amherst a methods project was carried out. The methods section in a piece of scientific writing is an important aspect of an experiment because it illustrates to other prospering scientists what they need to follow in order to obtain the same results. For this project I choose Euphorbia pulcherrima euphorbiaceae, which is a plant found in Mexico and Guatemala.  

Another prominent example of recent evolution resides within the ability to drink and digest milk. Most human adults are incapable of digesting lactose and therefore milk. Babies are capable of drinking milk due to a gene that codes for lactase, which breaks down lactose. In people who are lactose intolerant, the gene essentially switches off after weaning. However, a mutation known as lactase persistence arose in recent human history that allowed lactase to be produced into adulthood. This trait likely provided a selective advantage to individuals with access to domesticated dairy animals, who consumed the unfermented milk. “Analysis based on the conservation of lactase gene haplotypes indicates a recent origin and high selection coefficients for lactose persistence, although it has not been possible to say whether early Neolithic European populations were lactase persistent… (J. Burger et al., 2006)”

In 1958 nocturnal migratory species were observed to naturally turn and yearn to fly in their respective north-south directions relative to the time of year.  While in captivity, this behavior was replicated using a synthetic night sky inside a planetarium. However, when this was removed, the subjects were disoriented and lacked proper positioning. In addition, when the planetarium was reversed, the birds too reversed the direction of their desired movement. This concept was then elaborated on in 1967 by determining which starts or constellations were used by these subjects.  It was presumed that the north star, a large and fixed beacon, would be used, however it was determined that constellations near the north star, such as the big and little dipper, were used instead.  The subjects also showed flexibility and were able to utilize several constellations for travel when other were removed.

Foraminifera are ocean dwelling amoeba-like protists that build shells known as tests. The shell is referred to as a test because some of the protoplasm of the unicellular organism covers the outside of the test. Tests have chambers that are added as the cell grows. Shells or tests can be made of sand and bits of discarded shells that adhere to an exuded sticky substance, a hard keratin-like material, or calcite (calcium carbonate).  Foraminifera can be planktonic or benthic. Many tropical beaches are composed of sands made primarily from the skeletons of benthic foraminifera. Much of the ocean floor that is less than 4.000 m deep is covered by calcareous ooze composed of microfossil shells made of calcite. Foraminifera that secrete tests of calcite are not typically found below this depth because their skeletons dissolve. The calcite compensation depth (CCD) is the depth at which calcite dissolves and is typically 4,000 to 5,000 meters.  Below this depth forms that construct their tests from cemented grains of sand or other foreign particles are more common. 

NA species migrate on a north-south axis due to the fact that their wintering ranges lie south of their breeding ranges as well as the fact that the major mountain ranges in this region also follow this direction, such as the Appalachian or Rocky Mountains, preventing lateral travel. Species in EU and Asia migrate in a East to West direction due to the presence of major mountain ranges and deserts that spread on this axis such as the Alps and the Greater deserts of the middle east. These routes are sometimes fixed, ie species that have colonized a new land will occasionally return to their ancestral territory before embarking or they will eventually realign with the traditional route.  

There were some very significant differences between my figure and the figure that was replicated of mine. The first significant difference is the size of figure itself. The original figure being 2000x2000 pixel and the replicate being 300x200 pixels. In addition to the whole figure itself, each image itself in the multi-panel figure has much smaller dimensions in the replicate. Visually, size of both overall figure and individual images have a great difference. There was also much more white space between each image in the replicate than in the original figure that was used to divide each image in the figure.

Another major difference was the labeling of each image. In the replicate, there was an absence of labels in each image to distinguish them from one another. Meanwhile in the original, it contained image labeled, A, B, and C on the upper left-hand corner of each image to identify each.

A third major difference would be the difference in the images themselves. For image “A”, there was a difference in the angle or orientation at which the image was taken, both vertically and horizontally. Vertically, the replicate was taken at a much higher angle, taken at a close birds-eye-view. Horizontally, the replicate was taken in a direct line of sight as oppose to the original which was taken further left. The distance of the image taken relative to the plant was also greater in the replicate. For image “B” there were angle and distance differences as well. The vertical image angle of the replicate was directly above the flower, the original was lower in angle. The horizontal image angle is most noticeable. The replicate was taken at a horizontal 90-degree difference than the original. The distance, similar to image “A” was further in the replicate than the original.

The range map differences were quite noticeable as well, including the size, range, and color. The size of the range map in the replicate is much smaller as they included both North America and South America whole. In the original, it is focused primarily on South America where the plant range is limited to. The range of the plant on the replicate includes most of the Caribbean to include Cuba, Haiti, and the Dominican Republic. The original does not extend the range through the Caribbean. The range map itself in the replicate has a white background as oppose to the original which has the original light grey color background.

The photos is Figure 2 are larger than in Figure 1. The map in Figure 2C has more countries filled in red than in Figure 1C. In Figure 1, the labels of each photo are are located on the bottom left of Figure 1A and Figure 1B and on the top left of Figure 1C. In Figure 2, the labels are on the top left for each different photo, but the labels are significantly bigger than on Figure 1. Figure 1 also has more space between the individual photos compared to those is Figure 2.

Also the plant featured in Figure 2 is a lighter pink flower with leaves with different coloration than the plant featured in Figure 1 The angle of  Figure 1B is taken with the camera angled parallel to the flower, while Figure 2A is taken with the camera at a slight angle from left to right. Figure 2B shows more of the plant than Figure 1A. Figure 1A is taken with the camera at a diagonal while Figure 2B is taken with the camera straight and perpendicular to the plant.