From The Classroom To The Real World

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Sources

Sources The Sources used during the creation of these blogs are as follows Campbell, Neil A. Biology : A Global Approach . New York Pearson, 2018. ‌ Telford, Maximilian J., et al. “Phylogenomic Insights into Animal Evolution.” Current Biology , vol. 25, no. 19, Oct. 2015, pp. R876–R887, www.sciencedirect.com/science/article/pii/S0960982215009288, 10.1016/j.cub.2015.07.060. ‌

The Glass Lizard

Dear Reader, The following post will talk about the European legless lizard. Evolving from a different lineage of legless lizards than did snakes, the Glass Lizard (Ophisaurus apodus) or Sheltopusik shows vestigiality with small rear leg stubs (something some think of as an adaptation which assists with burrowing) and the skeletal musculature having traces of shoulders and a pelvis. Sadly it was hiding within a branch so the only picture taken from a fellow student is one with its head barely sticking out. Ophisaurus apodus Taken from Biology A Global Approach Phylum: Chordata Class: Reptilia (8200 species)- paraphyletic as it excludes both birds and mammals Note-The origin of reptiles lies between 310-320 million years ago in the late Carboniferous period Order: Squamata (8000 species)- Largest order of reptiles consisting of lizards, snakes, and amphisbaenians. Family: Anguidae (100 species) Genus: Pseudopus (one extant species remains) The lizard inhabits open country...

West African Lungfish

Dear Fellow Readers, This post talks about the African lungfish, specifically its classification within the Chordata phylum and its characteristics that demonstrate vestigiality. African Lungfish/ Protopterus annectens Phylum: Chordata Order: Dipnoi Family: Lepidosirenidae Genus: Protopterus Per the name, the African Lungfish is distributed throughout Africa. Being an obligate air breather they are seen in basins and rivers. As of today, there are only seven known species of lungfish, being found in Africa, South America, and Australia. Being abundant since the Triassic geologic period they are thought to be over 250 million years old (phylogenetically speaking). While they do retain marginal teeth and an ossified braincase it has been significantly reduced in size due to vestigiality. This is also visible in something called the cosmine which has been lost in post-Devonian (between ~419-358 million years ago) lungfishes. While called Lungfish they are actually able to live on lan...

Upside-down Jellyfish

Dear fellow reader, The following is information on the Upside-down jellyfish. Upside-down jellyfish/ Cassiopea xamachana The Upside-down jellyfish swim upside down to single-celled algae that live among their tentacles. The algae require sunlight thus the jellyfish swim upside down to accommodate. They are able to remain upside down due to the underneath suctioning itself to the seabed as a way to stabilize. The reason the jellyfish protects and accommodates the algae to this extent (photosynthetic dinoflagellates) is due to the fact that it produces oxygen for itself and the jellyfish it is attached to. They have a symbiotic mutualistic relationship and are typically found in the Gulf of Mexico in coral reefs and lagoons (warm parts of the western Atlantic Ocean). Phylum: Cnidaria (10,000)- Includes corals, jellies, and hydras They have a radially symmetrical body (diplobastic) that have a single opening serving as both mouth and anus Class: Scyphozoa (200)- some sci...

Flatfish and Sharks

Dear Readers, This post will talk about whether several flatfish observed illustrate convergent evolution or homologous evolution. We will also discuss the difference between sharks and 'ordinary fish' and how they are easily distinguished from one another. Flat Fish Those visible in the large monumental hall were The European Plaice/ Pleuronectes platessa and Sole/ Solea solea. European Plaice and Solea Solea Both flatfish come from the same order being Pleuronectiformes. They are both found in similar habitats like the Mediterranean and enjoy burrowing themselves in the sandy or muddy seabed. Since they come from the same order we can hypothesize that both the Common Sole and European Plaice have a common ancestor. Common Stingray with leopard shark directly above Unlike the two flatfish, Dasyatis pastinaca (Common Stingray) shares the same phylum with the flatfish, however not much else. Diverging into the class Chondrichthyes. Much like the flatfish they can be fou...

Artis

Today I went to the Artis Zoo in Amsterdam Through the study of Mollusca, Arthropoda, Amphibians, Cnidaria, Echinodermata, and Vertebrates I related organisms through homology and convergent evolution . Sadly certain areas of the zoo were closed off due to the corona measures so we were unable to see vestigial organs in whales or the several phyla displayed in the specimen cabinets at the beginning. To begin my visit, I walked into a large monumental hall with a vast amount of aquaria. From Flatfish and sharks to Tropical coral reefs (Echinodermata and Cnidaria) we talked about whether their characteristics were due to convergent evolution or not. I then moved on to a species I found particularly interesting called the Blind Cave Fish . The way it shifts direction before hitting the wall is fascinating. Also within the Amazon aquatic ecosystem, I found representatives of the Mollusca and Arthropoda phyla however I will not go into too much detail in terms of these two phyla...

Gymnosperms, Angiosperms, and the life cycle of all Plants

Hello everyone, Today I decided to think about the difference between Gymnosperms and Angiosperms. While Gymnosperms do have four phylum and Angiosperms one, Phylum Anthophyta/ Flowering plants compose around 250,000 known species while Gymnosperms altogether equate to around 806 known species. The major difference between Gymnosperms and Angiosperms is that one has seeds not enclosed in chambers while the other has its seeds develop inside chambers (within flowers). With the numbers above and the inclusion of nonvascular and seedless plants, we can approximate that nearly 90% of living plant species are angiosperms. Now let's talk about the life cycle of all plants. Plants go through a process called alternation of generations between gametophytes and sporophytes. While this does not occur in charophytes (there is always an exception to the rule in biology) this type of reproductive cycle came from green algae. Basically, the process goes as such: The gametophyte produces haplo...

The Evolution of Plants and how they came to be

To those interested in The Evolution of Plants and how they came to be, the following post is dedicated to you. First, let us briefly characterize the main groups of the plant kingdom. Focusing on extant lineages we can see the kingdom is divided into two main groups. Those groups being Nonvascular Plants (Bryophytes: Liverworts, Mosses, and Hornworts) and Vascular Plants (Seedless and With seed including Gymnosperms and Angiosperms. ). They are called vascular due to cells joined into tubes that transport nutrients and water throughout the body. The Ten Phyla of Extant Plants approximates the number of known plant species to be around 300,000. To see pictures of Bryophytes and Gymnosperms you can go back to my Hortus post . How did plants come to be? In Figure 29.6 it is seen that all Plants came from a common Ancestor of Green Alga, a group composed of many unicellular species and small colonial species. With the appearance of spores, early plants arose approximately 470 million...

Hortus

Dear readers, Today has finally come. In a group of three, I went to the Botanical Gardens. From Fungi, Moss, and Cyanobacteria to 15 meter-high tree ferns I learned about major evolutionary trends in plant life and how the expansion of specific plant phylum led to the Ice Ages occurring 400 million years ago to now. Fungi, Moss (Bryophyte), and cyanobacteria Zosterophyllum, Rhynia, Cooksonia, Psilotum/ Whisk Fern Encephalartos altensteinii or Eastern Cape Giant Cycad Until next time, Sol

What is Homology, and is Convergent Evolution somehow different?

Dear Readers, From Darwin's theory of natural selection to Lamarckian inheritance, evolutional theories have been created since the time of Greek philosophers. While the history of how evolution came to be so accepted is important this post will focus on the overwhelming amount of scientific evidence that supports it, specifically Homology and Convergent Evolution. Homology, in simple terms, describes the similarities among different organisms. Per a book called Biology a Global Approach, as descendants of a specific ancestral organism face different environmental conditions they can have characteristics that are similar, yet function in very different ways. This similarity is known as homology when it comes from a common ancestor. While not visible to the naked eye, genetic code is a homologous characteristic shared by all species from its LUCA (Last Universal Common Ancestor). In the coming days, I will be focusing more on homologous characteristics that evolved recently and are...