His idea of common descent was based on observations of homologous structures, convergence of form, embryology, vestigial structures and imperfect structures. A homologous structure is an example of an organ or bone that appears in different animals, showing similarities
The descendants of the first radiation of mammals, monotremes have characteristics of both placentals and marsupials, while still retaining characteristics of reptiles and birds in a combination all their own. Introduction At first glance platypuses seem to be an amalgamation of mammals, birds, and everything in between. In fact, their reproduction biology also has much in common with a variety of animals—reptiles, birds, placentals and marsupial mammals. Platypuses belong to a group of animals called monotremes. These egg-laying mammals have been a mystery to researchers since their discovery by Westerners over 200 years ago.
Lamarck- Lived from 1744-1829. Remembered for the incorrect proposals to explain how evolution occurs. By comparing living species with fossil forms, he had found what appeared to be several lines of descent; each differed by age and time. His two key principles are use and disuse, which was the idea that parts of the body that are used more become stronger and larger, and inheritance of acquired characteristics, which stated that an organism could pass these modifications to its offspring. Also though that evolution happens because organisms have an innate drive to become more
Nature is our DNA/genes. It is all about the biological factors that affect development. Nurture is how we are brought up. It is all about the socioeconomic and environmental factors which affect development. Historically, some philosophers and theorists have argued that we are born to be the way we are.
Some of the organisms such as Tesseropora Roseas (Barnacles) and Knobbly Winks have different adaptations, which allow them to survive in these harsh conditions. Competition with other organisms, availability of food and predation can also affect the abundance and distribution of rock-shelf organisms. To determine the abundance and distribution of these rock-shelf organisms a quadrat with an area of 0.5m2 was used. It was placed randomly in each location. Location 1 was above the high tide mark, Location 2 the tidal rock pools and location 3 the low tide mark.
The Analysis of Shellfish Muscel Proteins in Regard to Evolutionary Change Ramin Baimaninejad Lazia Leon-Guerrero Claire Edwards Michael Yacoub BIOL&212L Abstract: When observing the morphology of mussels, scallops, oysters, and clams one can observe the similarities in physical structure; the question is posed as to whether these traits are due to convergent evolution or genetic similarities. To better understand the evolutionary relationships between the shellfish muscle protein analysis was performed to find similarities and differences between the organisms. Samples of isolated proteins were extracted from the four stated species; shrimp protein was also extracted to serve as an out-group. The protein samples were analyzed via gel electrophoresis and protein mass fragments were weighed. It was found that scallops and clams had the closest relationship with a 44% protein match.
Evolution gives rise to diversity. The features of a common ancestor may have developed and been adapted for different environmental conditions, resulting in morphological differences between present day organisms. In order to make sense of the large diversity and form relationships between the organisms, organisms are classified into different groups. Members of each group have certain shared characteristics that distinguish them from members of other groups. This essay will compare two vermiform phyla, Platyhelminthes and Nematoda in terms of their physical traits, biological systems as well as ecological importance.
ECOLOGICAL ADAPTATION OF AQUATIC ORGANISMS INTRODUCTION All living organisms are affected by the environment they live in; therefore they have to undergo a few changes in order to fit in the environments they live in. Each ecosystem has its own environmental challenges and therefore the essence of this essay is to explain the ecological adaptation of aquatic organisms. The essay will start by defining the key words like adaptation and ecosystem followed by explaining the two types of aquatic ecosystems and how the aquatic organisms adapt in the two types of aquatic ecosystems. According to the Concise Oxford Dictionary (2004:5), adaptation is a change or the process of change by which an organism or species becomes better suited to its environment. According to Charles Darwin theory of evolution by natural selection, the organisms adapt to their environment to become better fitted to survive and passing their genes to the next generation.
o List and describe the evidence for evolution, which was presented by Darwin “Natural Selection” States that favourable variations on species are selected and harmful ones are eliminated according to the ability to survive in the environment. The four main points outlining natural selection are o No species has identical members o In every generation there are offspring that do not reach maturity, and as a result, the characteristics of these members are not carried on as they do not reproduce o Favourable variations allow for the adaptation of the stronger organisms to occur (survival of the fittest) o Favourable variations are passed on to offspring to allow for that trait to become more apparent in a species E.G. “Darwin observed (while on his visit to Australia)crows like our English jackdaws were not uncommon, and another bird something like a magpie. He also saw a rat-kangaroo (a potoroo) which he compared to a European rabbit both in size and behaviour”(2) Natural selection also leads to the evolution of new species. For example; by studying the skeletal and muscular structure in the Hawaiian honeycreeper, scientists were able to find similarities and could confirm that the current 23 species of honeycreepers all evolved from one ancestral species.