9. Does the appearance of the cavefish and the minnow suggest a common ancestry? Why?
The appearance of the cavefish and the minnow suggests a common ancestry since they possess homologous structures. Based on observations made on the characteristics of the cavefish and minnow, the structures of the fins, tails, and overall shape of the bodies make the two types of fish seem exceedingly related. Both fish share the same one-part dorsal fin, caudal fin (tail), anal fin, and pelvic fins. These fins or also likely similar in bones, cartilage, or muscle composition. Even more, both the minnow and cavefish share the same lateral line running down the middle of their bodies.
10.
Structure
Probable Function
Why Vestigial?
Appendix
Digest a cellulose/starch rich diet
Human diets changed from eating plants to other forms of sustenance
Coccyx (tail bone)
Helped the tail generate momentum to swing in trees
Humans evolved from moving among the trees to walking on lang
Muscle that move ears
Aid in hearing and tonal detection abilities
Humans moved away from relying on hearing as a main sense
Muscles that make hair stand up
Much like felines,
…show more content…
With convergent evolution, two structures have common features because of said structures fulfilling similar purposes despite having unrelated origins and ancestors. From this, regarding the fin of a fish and the flipper of a whale, it can be concluded that fishes and whales were subjected to similar environments even though both types of animals were previously independent of each other. Since both fish and whales are found in water, it may have been rising sea levels or weather changes that could have prompted the evolution. The evolution of a fish and whale do interact with each, as both evolve independently, but it just so happened that the evolutionary lines encountered similar environment
Seahorses are a prime example of species whose atypical biology and unusual global distribution leads to a series of evolutionary questions. Seahorses (genus Hippocampus) are a marine species that have extensively been studied because of their abnormal behaviors in the marine environment compared to other marine creatures. Many of the seahorse species have large ranges, both longitudinally (over a great horizontal distance across the ocean), and latitudinal (great vertical distance within the ocean), regardless of the fact that they are characterized as weak swimmers and lack any large structural fins for efficient swimming (Lourie et al., 1999a). Although they do have these large range environments, seahorses
Although the Hippocampus spp. are placed into the same class as other organisms more traditionally viewed as fish, their morphology bears distinct differences in comparison to other bony fish. The various species belonging under the genus Hippocampus range in maximum size from 20 mm to 300 mm(Foster 8). Their physical appearance is distinct from other members of its class due to their "horse-like head, monkey-like tail, and kangaroo-like pouch."( Lourie et al 12) Morphologically, seahorses do not have scales like traditional fish, but rather posses bony plates covered by skin. The appearance of bony extrusions and skin ...
Scientists had some idea to the evolutionary process of whales. “It has always been clear that aquatic cetaceans must have evolved from terrestrial mammals and returned to the water, and the forelimbs of recent cetaceans still have the same general pattern as that of land mammals.” (Walking with Whales) It was known fact that land mammals and whales were related. However, the change from ancient whales to modern whales is drastic.
Shubin, N.H., & Marshall, C.R. 2000. Fossils, genes and the origin of novelty. Paleobiology, 26(4): 324-340.
The origin of modern day whales, a mystery that has puzzled paleontologists for years, may have just been solved with the discovery of an ankle bone. This discovery might sound simple and unimportant, but the bones of these ancient animals hold many unanswered questions and provide solid proof of origin and behavior. The relationship between whales and other animals has proven to be difficult because whales are warm-blooded, like humans, yet they live in the sea. The fact that they are warm-blooded suggests that they are related to some type of land animal. However, the questions of exactly which animal, and how whales evolved from land to water, have remained unanswered until now.
The stories of each fish flow together as each story shows how humans have pushed to gain more control over the ocean and the delicious animals that swim in it’s depths. Greenberg starts in the free-flowing rivers where salmon are commonly found. It is there that early humans of the Northern Hemisphere most likely began their infatuation with fish. Greenberg puts it as, “It(salmon) is representative of the first wave of human exploitation..” (170) Once Europeans learned to fish, they had the ability to fish in shallow ocean water which is where sea bass are usually found. Later, fishermen s...
One of the previous papers in English class required the class to pick a paper to explore, this question will be concentrated on further in the synthesis essay. What evidence do scientist have to prove that prehistoric sharks existed? The reason behind picking this question wasn’t just to find proof that these monsters swam the seas, but to learn more about them from different resources. One of the resources that were used was a chapter in Angelo Mojetta’s book Sharks, called “ The Birth Of A Legend”. The other resource that was used for information was an article in Discovery Channels website called “ Prehistoric Sharks”. Sharks and Discovery Channel are the two resources that led to many other questions about their different, and similar views on prehistoric sharks existence.
That “prehistoric” whales had the jaw of a wolf (a fifty million year old wolf to be exact) and the ear of a whale. I think that all of our semiaquatic mammals play a big part in the evolution of land mammals to water mammals. Like at some point of say an otter’s life, nature told it to stop evolving so that it wouldn’t become completely marine, but semiaquatic as we named it. How did it know when to stop evolving? Was it changes in the environment? Or the need for survival? Which brings around another question, how did we go from a planet of just rock and magma, to a planet thriving with
The Axolotl, a crucially endangered neotenous species of mole salamander, has adapted to fit its environment so it can easily catch food and evade predators. The Axolotl’s habitat is the lake system of Xochimilco that is near Mexico City, Mexico. This shallow, fresh water lake complex has a temperature range of 6- 20°C and a pH of 7- 12. The complex also has the Axolotl’s primary food sources of mollusk, insect larvae, and other crustaceans. However, with the introduction of foreign species such as the Asian Carp and the African Tilapia, the Axolotl now has predators that may eat and threaten it, and it has competition for the animals it usually eats. Fortunately, the Axolotl has developed adaptations that aid it in catching food and evading predators. To help it catch food the Axolotl’s teeth are shaped like cones, so that its “vacuum” action of sucking in as much water in order to also eat food is aided by the shape of the teeth, which allow it to grip, rather than chew. To aid them in avoiding predators they are able to metamorphose so that they use their lungs more than their gill, which allows them to leave very toxic waters and the predators within. Another adaption that helps them deflect any predator is that they are able to regenerate body parts that have been lost, allowing them to stay as strong as possible. Axolotl’s have adaptations that aid their survival from predators in the lake complex Xochimilco that they reside in.
There’s No Real Good Guy In the movie, “Blackfish” we are exposed to the fact that the way orcas are treated at SeaWorld is worse than we are lead to believe. We see how they are forced to swim in tiny pools and how they can only be fed if they preform well. After seeing this it makes you feel like the only way to help these poor creatures is to jump on the animal activist wagon and to free all the whales like in “Free Willy”. But is that really the right way to go?
Just as in any other sport, understanding gives rise to advantage and success. As serious fishermen, we had dedicated much thought to understanding the fish, hypothesizing their behavior. One understanding we had already gained through previous experiences was that fish readily eat the prey that is normally available. This, we concluded, was a sort of defense against fishermen and their foreign lures and was acquired through the fishes’ own previous experience of eating a lure. In applying this understanding to our fishing, we performed a routine food chain analysis to find out what our lures needed to imitate. The results were that the part of the food chain just beneath our quarry consisted mostly of small fish such as anchovies and young yellowtail, smaller than those shad and bluegill normally eaten in freshwater ponds. To compensate for this difference we would have to use lures smaller than those we were used to using. Luckily we had some.
The morphology of whale sharks is mostly similar to aquatic fish species, but many specific traits help differentiate them from the rest. Whale sharks are the largest fish in the world and can reach a size of around 20 meters (Martins, C., and C. Knickle). This is often compared to the size of a school bus. The shark has a very large transverse mouth. They have 5 very large gill slits and have a larger first dorsal fin compared to the second one (Whale Shark). They have a distinctive spotted “checkerboard” pattern with stripes (Martins, C., and C. Knickle). It is not exactly known why they have this specific body marking. It is believed that the body markings act as a camouflage. The strange thing about whale sharks is that they have 300 rows of teeth that play no role in feeding (Martins, C., and C. Knickle).
When these alterations are helpful, they grow to be fixed in a population and can result in the evolution of new phyla. Evo-devo seeks to figure out how new groups happen by understanding how the method of development has evolved in different lineages. In other word, evo-devo explains the interaction between phenotype and genotype (Hall, 2007). Explanation of morphological novelty of evolutionary origins is one of the middle challenges in current evolutionary biology, and is intertwined with energetic discussion regarding how to connect developmental biology to standard perspectives from the theory of evolution (Laubichler, 2010). A large amount of theoretical and experiential effort is being devoted to novelties that have challenged biologists for more than one hundred years, for instance, the basis of fins in fish, the fin-to-limb change and the evolution of feathers.
Did you know in the world there are more than 90 species of whales, dolphins, and porpoises? (WDC) The dolphin is a very important animal to the ocean and there are many different types to discover. In order to learn about dolphins, it is important to discuss where they live, their appearance, and what they eat. Some helpful words to understand are “dorsal fin”, a dorsal fin is the top pointed fin on the dolphins back, “flippers”, a flipper is a flat fin that dolphins use to swim, and “echolocation” is a tool dolphins use to find food by sounds bouncing off of objects (dictionary.com).