If a lake is cut from the ocean and has no large fish as predators (only dragonflies), then the sticklebacks will have a better chance at surviving and reproducing because the sticklebacks will be better adapted to the environment (presence/absence of a pelvic bone) and have little to no predators. The hypothesis was supported. Before the experiment started, background knowledge was collected to better the knowledge of the lakes. Bear Paw Lake is an enclosed lake, meaning no predators could get into the lake. However, Frog Lake is connected to a water system by a small stream, thus allowing predators such as salmon to enter the lake. Twenty fish were collected from each lake and then put into a solution that stains the fish's bones. This makes …show more content…
Natural selection is the process by which evolution occurs where organisms that are better suited to the environment (‘fittest’) survive and pass on favorable traits to the offspring. Organisms must adapt to the environment in order to survive. The stickleback fish adapted to the environment by keeping/removing the pelvic structures. For example, in Frog Lake, the all of the sticklebacks had complete pelvic structures because the lake was connected to a system of streams that allowed predators into the lake. The sticklebacks in Bear Paw Lake had reduced or absent pelvic structures because little/no predators are present in the lake. The pelvic structures on the fish are similar to the legs of four-legged vertebrates. With this said, the pelvic structures are a very important to the survival/defense of a stickleback. The stickleback fish experiment was well designed for many reasons. First, the experiment contained all the variables of a well-designed experiment. The independent variable is the water source (lake) and the dependent variable being the amount of complete, reduced, or absent pelvic structures found in the fish. Also, the experiment contained a constant: the number of fish collected per lake (20). Secondly, the experiment contained lots of data and is
What were the variables? The independent variables are the male and female gender. The dependent variable are the dosage of bolus given. 1.
Does the amount of blubber an Hourglass Dolphin, Lagenorhynchus cruciger, has depend on the environment it inhabits? Introduction Lagenorhynchus cruciger, also known as the Hourglass Dolphin, is a small dolphin found in the Antarctic and Sub Antarctic waters, which tend to be anywhere between -2 and 10 degrees celsius in temperature. As mammals, they are warm-blooded, produce milk, give birth and take care of their young. The Hourglass Dolphin is black and white in colour, with some shades of grey, this pattern resembles an hourglass. They feed on mainly fish, squid and crustaceans.
External Anatomy Let’s start with the pectoral fins which are toward the front and side of the Dogfish Shark. The Dogfish has two dorsal fins, you have a anterior or first dorsal fin and a posterior or a second dorsal fin both have spines so look they looked closely and are available to locate them. As they go to the back of the shark the end is called the coddle fin. They turned the shark over to the ventral side.
For many it’s a first pet, a gift from family, something you won as a prize at a carnival, but for Canadian residents the familiar orange goldfish everyone knows and loves is becoming a serious problem. Some flush them in a hurry because they no longer want to take care of them, others commit them to a porcelain vortex because they believe their beloved fish has passed, and the Canadian Government is issuing a warning now to citizens of Canada to stop flushing their fish. Just a few goldfish with the potential to disrupt an entire ecosystem Goldfish are entering the ecosystem the way that a lot of invasive species end up in an environment they don’t belong, Humans are putting them there. Human interference is one of the leading causes of the beginning of over population of invading alien species. In this case many of the fish are going down drains, and ending up in Canada’s lakes and rivers.
The number of sea otters a long time ago was 150,000–300 000, but unfortunately because of the fur trade, they were hunted a lot for their expensive fur between 1741 and 1911. The world population of sea otters fell to only to about 1 000–2 000. But later after all that, there was an international ban on sea otter hunting, and reintroducing sea otters into previously populated areas has helped to repopulate the species. Because of all the human help the species now occupies has about two-thirds from the population number they had before. The recovery of the sea otter is considered an important success in marine conservation.
The author states that the pollution hypothesis seemed the most likely cause of otters decline along the Alaskan coast and provides three reasons. In contrast, the professor states that the ongiong investigation show that the predation theory is mst likely the cause of the decline and sh.e opposes each of the author 's reasons First, the reading claims that there were known sources of pollution along the Alaskan coast. However, the professor refutes this pint by saying that the pollution theory is weakened by that no dead sea otters were washed up to the shore. She said thet if the infection is the cause of the decline, there should be a lot of killed otters washed up, so this fact is consistent with the predation theory because if the sear otters were killedby predetors, they would not wash up to the shore.
I can’t believe what just happened! Today, my goldfish died! About 2 weeks ago I won little bubbles at a carnival. As long as I have lived I have begged my parents to get a goldfish! That day was the happiest day of my life.
Gila trout are endangered in some stretches of water that are managed as designated wilderness. A hands-off policy would be their doom. Because exotic trout species now swim in the same streams, Gila trout can survive the competition and the temptation to interbreed only if they swim in isolated tributaries. In which a water-fall blocks the upstream movement of other fish. Two decades ago, one such tributary was fortified.
Vertebrates are known to be animals with backbones. Tooth reduction is one of the major evolutionary trends that developed among major vertebrate groups that allowed for the transition from aquatic to terrestrial life. Evolution of limbs and being able to breath air are other evolutionary trends that took placeThese trends include improved respiration and protective and insulating body coverings. More over the transition from water to land also included changing to more efficient reproductive methods like having a placenta for some animals or egg layers for other animals. Lastly, the morphology of organisms evolved such that for land they would have paired, muscular appendages used for crawling and
In my hypothesis, I state that the stickleback fish would not have a pelvic spine caused by an insertion mutation in the Pitx1 enhancer region. According to the gel, the stickleback fish in Big Lake do not have the pelvic spine due to a deletion mutation found in the Pitx1 enhancer region. This can be further proved by the phenotype of the fish found in Big lake. The stickleback fish found in Big Lake (seen in figure 2) is smooth across the bottom, with no pelvic spine present. This proof supports the results of the gel
Polyandry in Anuran Amphibians Polyandry is a breeding pattern where the female mates with multiple males in one mating season, this topic is described by Byrne and Roberts (2012) as a poorly understood topic in evolutionary biology. Polyandry has two types in taxa with external fertilization, e.g. anuran amphibians: simultaneous and sequential polyandry. Simultaneous polyandry occurs when sperm from multiple males compete to fertilize eggs. Sequential polyandry occurs when the eggs from a single female are fertilized by multiple males and sperm competition is absent (Byrne and Roberts 2012).
In Essentials of Biology, natural selection is categorized under ‘Evolution on a Small Scale’, but while natural selection is typically not a drastic, abrupt force that causes huge leaps and bounds in evolution in a short time, natural selection applies to all living things. Natural selection is a process which causes a population (interbred organisms in the same place at the same time) to adapt, meaning, to undergo a change in characteristics to be better suited to their environment. Natural selection is what allows members of a population, who are better suited to their environment, to live. There are various results of natural selection, such as an average phenotype becoming more prominent when nature favors less extreme variation (stabilizing
Natural selection is a process of nature. It decides who survives to procreate, and those who die along the way. Natural selection is often described as “Survival of the Fittest”, which is actually not a bad way to describe it. All animals are born with variations, from fur color, eye color, beak size, paw size, you name it and it is almost definitely variant. Most of those variants can affect an animal's ability to survive in their environment.
Jean-Baptiste Lamarck, a zoologist in the eighteenth and nineteenth century, noticed the different environments caused the wide variations between aquatic animals. In his book Hydrogeologie, Lamarck outlines the how fish became land dwelling creatures, “…by the different environment provided by the waters, nature led them a little by little to the habit of living in the air, first by the water’s edge and afterward on all the dry parts of the globe. Animals have in course of time been profoundly altered by such novel conditions; which so greatly influenced their habits and organs.” Lamarck was one of the first scientists to notice the variations between the same or similar species in different environments, which Darwin would eventually describe as natural
Nat Crocker Introduction Sexual selection is the an accepted theory that is found when a gender of a species chooses (selects ) his or her mate. Charles Darwin put it as, “…the advantage, which certain individuals have over others of the same sex and species solely in respect of reproduction.” (http://infidels.org/library/historical/charles_darwin/descent_of_man/chapter_08.html)